f

core/src/main/java/art/arcane/iris/core/tools/IrisCreator.java

@@ -342,11 +342,16 @@ public class IrisCreator {
         int chunkX = rawLocation.getBlockX() >> 4;
         int chunkZ = rawLocation.getBlockZ() >> 4;
         try {
-            CompletableFuture<Chunk> chunkFuture = PaperLib.getChunkAtAsync(world, chunkX, chunkZ, true);
+            CompletableFuture<Chunk> chunkFuture = PaperLib.getChunkAtAsync(world, chunkX, chunkZ, false);
             if (chunkFuture != null) {
-                chunkFuture.get(15, TimeUnit.SECONDS);
+                chunkFuture.get(10, TimeUnit.SECONDS);
             }
         } catch (Throwable ignored) {
+            return rawLocation;
+        }
+
+        if (!world.isChunkLoaded(chunkX, chunkZ)) {
+            return rawLocation;
         }
 
         CompletableFuture<Location> regionFuture = new CompletableFuture<>();
@@ -376,19 +381,19 @@ public class IrisCreator {
         int z = source.getBlockZ();
         int minY = world.getMinHeight() + 1;
         int maxY = world.getMaxHeight() - 2;
-        int topY = world.getHighestBlockYAt(x, z, HeightMap.MOTION_BLOCKING_NO_LEAVES);
-        int startY = Math.max(minY, Math.min(maxY, topY + 1));
+        int sourceY = source.getBlockY();
+        int startY = Math.max(minY, Math.min(maxY, sourceY));
         float yaw = source.getYaw();
         float pitch = source.getPitch();
 
-        int upperBound = Math.min(maxY, startY + 16);
+        int upperBound = Math.min(maxY, startY + 32);
         for (int y = startY; y <= upperBound; y++) {
             if (isSafeStandingLocation(world, x, y, z)) {
                 return new Location(world, x + 0.5D, y, z + 0.5D, yaw, pitch);
             }
         }
 
-        int lowerBound = Math.max(minY, startY - 24);
+        int lowerBound = Math.max(minY, startY - 64);
         for (int y = startY - 1; y >= lowerBound; y--) {
             if (isSafeStandingLocation(world, x, y, z)) {
                 return new Location(world, x + 0.5D, y, z + 0.5D, yaw, pitch);

core/src/main/java/art/arcane/iris/engine/IrisComplex.java

@@ -433,6 +433,10 @@ public class IrisComplex implements DataProvider {
 
         for (IrisGenerator gen : generators) {
             String key = gen.getLoadKey();
+            if (key == null || key.isBlank()) {
+                continue;
+            }
+
             max += biome.getGenLinkMax(key, engine);
             min += biome.getGenLinkMin(key, engine);
         }

core/src/main/java/art/arcane/iris/engine/IrisEngine.java

@@ -107,6 +107,7 @@ public class IrisEngine implements Engine {
     private double maxBiomeLayerDensity;
     private double maxBiomeDecoratorDensity;
     private IrisComplex complex;
+    private final AtomicBoolean modeFallbackLogged;
 
     public IrisEngine(EngineTarget target, boolean studio) {
         this.studio = studio;
@@ -129,6 +130,7 @@ public class IrisEngine implements Engine {
         context = new IrisContext(this);
         cleaning = new AtomicBoolean(false);
         noisemapPrebakeRunning = new AtomicBoolean(false);
+        modeFallbackLogged = new AtomicBoolean(false);
         execution = getData().getEnvironment().with(this);
         if (studio) {
             getData().dump();
@@ -165,10 +167,29 @@ public class IrisEngine implements Engine {
     }
 
     private void prehotload() {
-        worldManager.close();
-        complex.close();
-        effects.close();
-        mode.close();
+        EngineWorldManager currentWorldManager = worldManager;
+        worldManager = null;
+        if (currentWorldManager != null) {
+            currentWorldManager.close();
+        }
+
+        IrisComplex currentComplex = complex;
+        complex = null;
+        if (currentComplex != null) {
+            currentComplex.close();
+        }
+
+        EngineEffects currentEffects = effects;
+        effects = null;
+        if (currentEffects != null) {
+            currentEffects.close();
+        }
+
+        EngineMode currentMode = mode;
+        mode = null;
+        if (currentMode != null) {
+            currentMode.close();
+        }
         execution = getData().getEnvironment().with(this);
 
         J.a(() -> new IrisProject(getData().getDataFolder()).updateWorkspace());
@@ -178,12 +199,14 @@ public class IrisEngine implements Engine {
         try {
             Iris.debug("Setup Engine " + getCacheID());
             cacheId = RNG.r.nextInt();
-            worldManager = new IrisWorldManager(this);
-            complex = new IrisComplex(this);
+            complex = ensureComplex();
             effects = new IrisEngineEffects(this);
             hash32 = new CompletableFuture<>();
             mantle.hotload();
             setupMode();
+            IrisWorldManager manager = new IrisWorldManager(this);
+            worldManager = manager;
+            manager.startManager();
             getDimension().getEngineScripts().forEach(execution::execute);
             J.a(this::computeBiomeMaxes);
             J.a(() -> {
@@ -207,11 +230,76 @@ public class IrisEngine implements Engine {
     }
 
     private void setupMode() {
-        if (mode != null) {
-            mode.close();
+        EngineMode currentMode = mode;
+        if (currentMode != null) {
+            currentMode.close();
         }
 
-        mode = getDimension().getMode().create(this);
+        mode = null;
+        mode = ensureMode();
+    }
+
+    private EngineMode ensureMode() {
+        EngineMode currentMode = mode;
+        if (currentMode != null) {
+            return currentMode;
+        }
+
+        synchronized (this) {
+            currentMode = mode;
+            if (currentMode != null) {
+                return currentMode;
+            }
+
+            try {
+                IrisComplex readyComplex = ensureComplex();
+                if (readyComplex == null) {
+                    throw new IllegalStateException("Iris complex is unavailable");
+                }
+
+                IrisDimensionMode configuredMode = getDimension().getMode();
+                if (configuredMode == null) {
+                    configuredMode = new IrisDimensionMode();
+                    getDimension().setMode(configuredMode);
+                }
+
+                currentMode = configuredMode.create(this);
+                if (currentMode == null) {
+                    throw new IllegalStateException("Dimension mode factory returned null");
+                }
+            } catch (Throwable e) {
+                Iris.reportError(e);
+                if (modeFallbackLogged.compareAndSet(false, true)) {
+                    Iris.warn("Failed to initialize configured dimension mode for " + getDimension().getLoadKey() + ", falling back to OVERWORLD mode.");
+                }
+                currentMode = IrisDimensionModeType.OVERWORLD.create(this);
+            }
+
+            mode = currentMode;
+            return currentMode;
+        }
+    }
+
+    private IrisComplex ensureComplex() {
+        IrisComplex currentComplex = complex;
+        if (currentComplex != null) {
+            return currentComplex;
+        }
+
+        if (closed) {
+            return null;
+        }
+
+        synchronized (this) {
+            currentComplex = complex;
+            if (currentComplex != null) {
+                return currentComplex;
+            }
+
+            currentComplex = new IrisComplex(this);
+            complex = currentComplex;
+            return currentComplex;
+        }
     }
 
     private void scheduleStartupNoisemapPrebake() {
@@ -447,17 +535,39 @@ public class IrisEngine implements Engine {
         PregeneratorJob.shutdownInstance();
         closed = true;
         J.car(art);
-        getWorldManager().close();
+        EngineWorldManager currentWorldManager = getWorldManager();
+        if (currentWorldManager != null) {
+            currentWorldManager.close();
+        }
         getTarget().close();
         saveEngineData();
         getMantle().close();
-        getComplex().close();
-        mode.close();
+        IrisComplex currentComplex = complex;
+        if (currentComplex != null) {
+            currentComplex.close();
+        }
+        complex = null;
+        EngineMode currentMode = mode;
+        if (currentMode != null) {
+            currentMode.close();
+        }
+        mode = null;
+        effects = null;
+        worldManager = null;
         getData().dump();
         getData().clearLists();
         Iris.service(PreservationSVC.class).dereference();
         Iris.debug("Engine Fully Shutdown!");
-        complex = null;
+    }
+
+    @Override
+    public IrisComplex getComplex() {
+        return ensureComplex();
+    }
+
+    @Override
+    public EngineMode getMode() {
+        return ensureMode();
     }
 
     @Override
@@ -510,7 +620,8 @@ public class IrisEngine implements Engine {
                     }
                 }
             } else {
-                mode.generate(x, z, blocks, vbiomes, multicore);
+                EngineMode activeMode = ensureMode();
+                activeMode.generate(x, z, blocks, vbiomes, multicore);
             }
 
             World realWorld = getWorld().realWorld();

core/src/main/java/art/arcane/iris/engine/IrisWorldManager.java

@@ -195,7 +195,12 @@ public class IrisWorldManager extends EngineAssignedWorldManager {
         };
         looper.setPriority(Thread.MIN_PRIORITY);
         looper.setName("Iris World Manager " + getTarget().getWorld().name());
-        looper.start();
+    }
+
+    public void startManager() {
+        if (!looper.isAlive()) {
+            looper.start();
+        }
     }
 
     private void discoverChunks() {
@@ -528,6 +533,11 @@ public class IrisWorldManager extends EngineAssignedWorldManager {
             return;
         }
 
+        IrisComplex complex = getEngine().getComplex();
+        if (complex == null) {
+            return;
+        }
+
         if (initial) {
             energy += 1.2;
         }

core/src/main/java/art/arcane/iris/engine/mantle/components/IrisCaveCarver3D.java

@@ -0,0 +1,265 @@
+/*
+ * Iris is a World Generator for Minecraft Bukkit Servers
+ * Copyright (c) 2022 Arcane Arts (Volmit Software)
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package art.arcane.iris.engine.mantle.components;
+
+import art.arcane.iris.core.loader.IrisData;
+import art.arcane.iris.engine.framework.Engine;
+import art.arcane.iris.engine.mantle.MantleWriter;
+import art.arcane.iris.engine.object.IrisCaveFieldModule;
+import art.arcane.iris.engine.object.IrisCaveProfile;
+import art.arcane.iris.engine.object.IrisRange;
+import art.arcane.iris.util.project.noise.CNG;
+import art.arcane.volmlib.util.collection.KList;
+import art.arcane.volmlib.util.math.RNG;
+import art.arcane.volmlib.util.matter.MatterCavern;
+
+public class IrisCaveCarver3D {
+    private static final byte LIQUID_AIR = 0;
+    private static final byte LIQUID_WATER = 1;
+    private static final byte LIQUID_LAVA = 2;
+    private static final byte LIQUID_FORCED_AIR = 3;
+
+    private final Engine engine;
+    private final IrisData data;
+    private final IrisCaveProfile profile;
+    private final CNG baseDensity;
+    private final CNG detailDensity;
+    private final CNG warpDensity;
+    private final CNG surfaceBreakDensity;
+    private final RNG thresholdRng;
+    private final KList<ModuleState> modules;
+    private final double normalization;
+    private final MatterCavern carveAir;
+    private final MatterCavern carveWater;
+    private final MatterCavern carveLava;
+    private final MatterCavern carveForcedAir;
+
+    public IrisCaveCarver3D(Engine engine, IrisCaveProfile profile) {
+        this.engine = engine;
+        this.data = engine.getData();
+        this.profile = profile;
+        this.carveAir = new MatterCavern(true, "", LIQUID_AIR);
+        this.carveWater = new MatterCavern(true, "", LIQUID_WATER);
+        this.carveLava = new MatterCavern(true, "", LIQUID_LAVA);
+        this.carveForcedAir = new MatterCavern(true, "", LIQUID_FORCED_AIR);
+        this.modules = new KList<>();
+
+        RNG baseRng = new RNG(engine.getSeedManager().getCarve());
+        this.baseDensity = profile.getBaseDensityStyle().create(baseRng.nextParallelRNG(934_447), data);
+        this.detailDensity = profile.getDetailDensityStyle().create(baseRng.nextParallelRNG(612_991), data);
+        this.warpDensity = profile.getWarpStyle().create(baseRng.nextParallelRNG(770_713), data);
+        this.surfaceBreakDensity = profile.getSurfaceBreakStyle().create(baseRng.nextParallelRNG(341_219), data);
+        this.thresholdRng = baseRng.nextParallelRNG(489_112);
+
+        double weight = Math.abs(profile.getBaseWeight()) + Math.abs(profile.getDetailWeight());
+        int index = 0;
+        for (IrisCaveFieldModule module : profile.getModules()) {
+            CNG moduleDensity = module.getStyle().create(baseRng.nextParallelRNG(1_000_003L + (index * 65_537L)), data);
+            ModuleState state = new ModuleState(module, moduleDensity);
+            modules.add(state);
+            weight += Math.abs(state.weight);
+            index++;
+        }
+
+        normalization = weight <= 0 ? 1 : weight;
+    }
+
+    public int carve(MantleWriter writer, int chunkX, int chunkZ) {
+        int worldHeight = writer.getMantle().getWorldHeight();
+        int minY = Math.max(0, (int) Math.floor(profile.getVerticalRange().getMin()));
+        int maxY = Math.min(worldHeight - 1, (int) Math.ceil(profile.getVerticalRange().getMax()));
+        int sampleStep = Math.max(1, profile.getSampleStep());
+        int surfaceClearance = Math.max(0, profile.getSurfaceClearance());
+        int surfaceBreakDepth = Math.max(0, profile.getSurfaceBreakDepth());
+        double surfaceBreakNoiseThreshold = profile.getSurfaceBreakNoiseThreshold();
+        double surfaceBreakThresholdBoost = Math.max(0, profile.getSurfaceBreakThresholdBoost());
+        int waterMinDepthBelowSurface = Math.max(0, profile.getWaterMinDepthBelowSurface());
+        boolean waterRequiresFloor = profile.isWaterRequiresFloor();
+        boolean allowSurfaceBreak = profile.isAllowSurfaceBreak();
+        if (maxY < minY) {
+            return 0;
+        }
+
+        int x0 = chunkX << 4;
+        int z0 = chunkZ << 4;
+        int carved = 0;
+
+        for (int x = x0; x < x0 + 16; x++) {
+            for (int z = z0; z < z0 + 16; z++) {
+                double threshold = profile.getDensityThreshold().get(thresholdRng, x, z, data) - profile.getThresholdBias();
+                int columnSurface = engine.getHeight(x, z);
+                int clearanceTopY = Math.min(maxY, Math.max(minY, columnSurface - surfaceClearance));
+                boolean surfaceBreakColumn = allowSurfaceBreak
+                        && signed(surfaceBreakDensity.noise(x, z)) >= surfaceBreakNoiseThreshold;
+                int columnMaxY = surfaceBreakColumn
+                        ? Math.min(maxY, Math.max(minY, columnSurface))
+                        : clearanceTopY;
+                int surfaceBreakFloorY = Math.max(minY, columnSurface - surfaceBreakDepth);
+                if (columnMaxY < minY) {
+                    continue;
+                }
+
+                for (int y = minY; y <= columnMaxY; y += sampleStep) {
+                    double localThreshold = threshold;
+                    if (surfaceBreakColumn && y >= surfaceBreakFloorY) {
+                        localThreshold += surfaceBreakThresholdBoost;
+                    }
+
+                    if (sampleDensity(x, y, z) <= localThreshold) {
+                        int carveMaxY = Math.min(columnMaxY, y + sampleStep - 1);
+                        for (int yy = y; yy <= carveMaxY; yy++) {
+                            writer.setData(x, yy, z, resolveMatter(x, yy, z, localThreshold, waterMinDepthBelowSurface, waterRequiresFloor));
+                            carved++;
+                        }
+                    }
+                }
+            }
+        }
+
+        return carved;
+    }
+
+    private double sampleDensity(int x, int y, int z) {
+        double warpedX = x;
+        double warpedY = y;
+        double warpedZ = z;
+        double warpStrength = profile.getWarpStrength();
+
+        if (warpStrength > 0) {
+            double offsetX = signed(warpDensity.noise(x, y, z)) * warpStrength;
+            double offsetY = signed(warpDensity.noise(y, z, x)) * warpStrength;
+            double offsetZ = signed(warpDensity.noise(z, x, y)) * warpStrength;
+            warpedX += offsetX;
+            warpedY += offsetY;
+            warpedZ += offsetZ;
+        }
+
+        double density = signed(baseDensity.noise(warpedX, warpedY, warpedZ)) * profile.getBaseWeight();
+        density += signed(detailDensity.noise(warpedX, warpedY, warpedZ)) * profile.getDetailWeight();
+
+        for (ModuleState module : modules) {
+            if (y < module.minY || y > module.maxY) {
+                continue;
+            }
+
+            double moduleDensity = signed(module.density.noise(warpedX, warpedY, warpedZ)) - module.threshold;
+            if (module.invert) {
+                moduleDensity = -moduleDensity;
+            }
+
+            density += moduleDensity * module.weight;
+        }
+
+        return density / normalization;
+    }
+
+    private MatterCavern resolveMatter(int x, int y, int z, double localThreshold, int waterMinDepthBelowSurface, boolean waterRequiresFloor) {
+        int lavaHeight = engine.getDimension().getCaveLavaHeight();
+        int fluidHeight = engine.getDimension().getFluidHeight();
+
+        if (profile.isAllowLava() && y <= lavaHeight) {
+            return carveLava;
+        }
+
+        if (profile.isAllowWater() && y <= fluidHeight) {
+            int surfaceY = engine.getHeight(x, z);
+            if (surfaceY - y < waterMinDepthBelowSurface) {
+                return carveAir;
+            }
+
+            double depthFactor = Math.max(0, Math.min(1.5, (fluidHeight - y) / 48D));
+            double cutoff = 0.35 + (depthFactor * 0.2);
+            double aquifer = signed(detailDensity.noise(x, y * 0.5D, z));
+            if (aquifer <= cutoff) {
+                return carveAir;
+            }
+
+            if (waterRequiresFloor && !hasAquiferCupSupport(x, y, z, localThreshold)) {
+                return carveAir;
+            }
+
+            return carveWater;
+        }
+
+        if (!profile.isAllowLava() && y <= lavaHeight) {
+            return carveForcedAir;
+        }
+
+        return carveAir;
+    }
+
+    private boolean hasAquiferCupSupport(int x, int y, int z, double threshold) {
+        int floorY = Math.max(0, y - 1);
+        int deepFloorY = Math.max(0, y - 2);
+        int aboveY = Math.min(engine.getHeight() - 1, y + 1);
+        if (!isDensitySolid(x, floorY, z, threshold)) {
+            return false;
+        }
+
+        if (!isDensitySolid(x, deepFloorY, z, threshold - 0.05D)) {
+            return false;
+        }
+
+        int support = 0;
+        if (isDensitySolid(x + 1, y, z, threshold)) {
+            support++;
+        }
+        if (isDensitySolid(x - 1, y, z, threshold)) {
+            support++;
+        }
+        if (isDensitySolid(x, y, z + 1, threshold)) {
+            support++;
+        }
+        if (isDensitySolid(x, y, z - 1, threshold)) {
+            support++;
+        }
+        if (isDensitySolid(x, aboveY, z, threshold)) {
+            support++;
+        }
+
+        return support >= 4;
+    }
+
+    private boolean isDensitySolid(int x, int y, int z, double threshold) {
+        return sampleDensity(x, y, z) > threshold;
+    }
+
+    private double signed(double value) {
+        return (value * 2D) - 1D;
+    }
+
+    private static final class ModuleState {
+        private final CNG density;
+        private final int minY;
+        private final int maxY;
+        private final double weight;
+        private final double threshold;
+        private final boolean invert;
+
+        private ModuleState(IrisCaveFieldModule module, CNG density) {
+            IrisRange range = module.getVerticalRange();
+            this.density = density;
+            this.minY = (int) Math.floor(range.getMin());
+            this.maxY = (int) Math.ceil(range.getMax());
+            this.weight = module.getWeight();
+            this.threshold = module.getThreshold();
+            this.invert = module.isInvert();
+        }
+    }
+}

core/src/main/java/art/arcane/iris/engine/mantle/components/MantleCarvingComponent.java

@@ -25,14 +25,21 @@ import art.arcane.iris.engine.mantle.IrisMantleComponent;
 import art.arcane.iris.engine.mantle.MantleWriter;
 import art.arcane.iris.engine.object.IrisBiome;
 import art.arcane.iris.engine.object.IrisCarving;
+import art.arcane.iris.engine.object.IrisCaveProfile;
+import art.arcane.iris.engine.object.IrisDimension;
 import art.arcane.iris.engine.object.IrisRegion;
 import art.arcane.iris.util.project.context.ChunkContext;
 import art.arcane.volmlib.util.documentation.ChunkCoordinates;
 import art.arcane.volmlib.util.mantle.flag.ReservedFlag;
 import art.arcane.volmlib.util.math.RNG;
 
+import java.util.IdentityHashMap;
+import java.util.Map;
+
 @ComponentFlag(ReservedFlag.CARVED)
 public class MantleCarvingComponent extends IrisMantleComponent {
+    private final Map<IrisCaveProfile, IrisCaveCarver3D> profileCarvers = new IdentityHashMap<>();
+
     public MantleCarvingComponent(EngineMantle engineMantle) {
         super(engineMantle, ReservedFlag.CARVED, 0);
     }
@@ -49,9 +56,18 @@ public class MantleCarvingComponent extends IrisMantleComponent {
 
     @ChunkCoordinates
     private void carve(MantleWriter writer, RNG rng, int cx, int cz, IrisRegion region, IrisBiome biome) {
-        carve(getDimension().getCarving(), writer, new RNG((rng.nextLong() * cx) + 490495 + cz), cx, cz);
-        carve(biome.getCarving(), writer, new RNG((rng.nextLong() * cx) + 490495 + cz), cx, cz);
-        carve(region.getCarving(), writer, new RNG((rng.nextLong() * cx) + 490495 + cz), cx, cz);
+        IrisCaveProfile dimensionProfile = getDimension().getCaveProfile();
+        IrisCaveProfile biomeProfile = biome.getCaveProfile();
+        IrisCaveProfile regionProfile = region.getCaveProfile();
+        IrisCaveProfile activeProfile = resolveActiveProfile(dimensionProfile, regionProfile, biomeProfile);
+        if (isProfileEnabled(activeProfile)) {
+            carveProfile(activeProfile, writer, cx, cz);
+            return;
+        }
+
+        carve(getDimension().getCarving(), writer, nextCarveRng(rng, cx, cz), cx, cz);
+        carve(biome.getCarving(), writer, nextCarveRng(rng, cx, cz), cx, cz);
+        carve(region.getCarving(), writer, nextCarveRng(rng, cx, cz), cx, cz);
     }
 
     @ChunkCoordinates
@@ -59,17 +75,60 @@ public class MantleCarvingComponent extends IrisMantleComponent {
         carving.doCarving(writer, rng, getEngineMantle().getEngine(), cx << 4, -1, cz << 4, 0);
     }
 
+    private RNG nextCarveRng(RNG rng, int cx, int cz) {
+        return new RNG((rng.nextLong() * cx) + 490495L + cz);
+    }
+
+    @ChunkCoordinates
+    private void carveProfile(IrisCaveProfile profile, MantleWriter writer, int cx, int cz) {
+        if (!isProfileEnabled(profile)) {
+            return;
+        }
+
+        IrisCaveCarver3D carver = getCarver(profile);
+        carver.carve(writer, cx, cz);
+    }
+
+    private IrisCaveCarver3D getCarver(IrisCaveProfile profile) {
+        synchronized (profileCarvers) {
+            IrisCaveCarver3D carver = profileCarvers.get(profile);
+            if (carver != null) {
+                return carver;
+            }
+
+            IrisCaveCarver3D createdCarver = new IrisCaveCarver3D(getEngineMantle().getEngine(), profile);
+            profileCarvers.put(profile, createdCarver);
+            return createdCarver;
+        }
+    }
+
+    private boolean isProfileEnabled(IrisCaveProfile profile) {
+        return profile != null && profile.isEnabled();
+    }
+
+    private IrisCaveProfile resolveActiveProfile(IrisCaveProfile dimensionProfile, IrisCaveProfile regionProfile, IrisCaveProfile biomeProfile) {
+        if (isProfileEnabled(biomeProfile)) {
+            return biomeProfile;
+        }
+
+        if (isProfileEnabled(regionProfile)) {
+            return regionProfile;
+        }
+
+        return dimensionProfile;
+    }
+
     protected int computeRadius() {
-        var dimension = getDimension();
+        IrisDimension dimension = getDimension();
         int max = 0;
 
         max = Math.max(max, dimension.getCarving().getMaxRange(getData(), 0));
 
-        for (var i : dimension.getAllRegions(this::getData)) {
+        for (IrisRegion i : dimension.getAllRegions(this::getData)) {
             max = Math.max(max, i.getCarving().getMaxRange(getData(), 0));
         }
 
-        for (var i : dimension.getAllBiomes(this::getData)) {
+        for (IrisBiome i : dimension.getAllBiomes(this::getData)) {
             max = Math.max(max, i.getCarving().getMaxRange(getData(), 0));
         }
 

core/src/main/java/art/arcane/iris/engine/mantle/components/MantleObjectComponent.java

@@ -63,21 +63,29 @@ public class MantleObjectComponent extends IrisMantleComponent {
         int xxx = 8 + (x << 4);
         int zzz = 8 + (z << 4);
         IrisRegion region = getComplex().getRegionStream().get(xxx, zzz);
-        IrisBiome biome = getComplex().getTrueBiomeStream().get(xxx, zzz);
+        IrisBiome surfaceBiome = getComplex().getTrueBiomeStream().get(xxx, zzz);
+        IrisBiome caveBiome = getComplex().getCaveBiomeStream().get(xxx, zzz);
         if (traceRegen) {
             Iris.info("Regen object layer start: chunk=" + x + "," + z
-                    + " biome=" + biome.getLoadKey()
+                    + " surfaceBiome=" + surfaceBiome.getLoadKey()
+                    + " caveBiome=" + caveBiome.getLoadKey()
                     + " region=" + region.getLoadKey()
-                    + " biomePlacers=" + biome.getSurfaceObjects().size()
-                    + " regionPlacers=" + region.getSurfaceObjects().size());
+                    + " biomeSurfacePlacers=" + surfaceBiome.getSurfaceObjects().size()
+                    + " biomeCavePlacers=" + caveBiome.getCarvingObjects().size()
+                    + " regionSurfacePlacers=" + region.getSurfaceObjects().size()
+                    + " regionCavePlacers=" + region.getCarvingObjects().size());
         }
-        ObjectPlacementSummary summary = placeObjects(writer, rng, x, z, biome, region, traceRegen);
+        ObjectPlacementSummary summary = placeObjects(writer, rng, x, z, surfaceBiome, caveBiome, region, traceRegen);
         if (traceRegen) {
             Iris.info("Regen object layer done: chunk=" + x + "," + z
-                    + " biomePlacersChecked=" + summary.biomePlacersChecked()
-                    + " biomePlacersTriggered=" + summary.biomePlacersTriggered()
-                    + " regionPlacersChecked=" + summary.regionPlacersChecked()
-                    + " regionPlacersTriggered=" + summary.regionPlacersTriggered()
+                    + " biomeSurfacePlacersChecked=" + summary.biomeSurfacePlacersChecked()
+                    + " biomeSurfacePlacersTriggered=" + summary.biomeSurfacePlacersTriggered()
+                    + " biomeCavePlacersChecked=" + summary.biomeCavePlacersChecked()
+                    + " biomeCavePlacersTriggered=" + summary.biomeCavePlacersTriggered()
+                    + " regionSurfacePlacersChecked=" + summary.regionSurfacePlacersChecked()
+                    + " regionSurfacePlacersTriggered=" + summary.regionSurfacePlacersTriggered()
+                    + " regionCavePlacersChecked=" + summary.regionCavePlacersChecked()
+                    + " regionCavePlacersTriggered=" + summary.regionCavePlacersTriggered()
                     + " objectAttempts=" + summary.objectAttempts()
                     + " objectPlaced=" + summary.objectPlaced()
                     + " objectRejected=" + summary.objectRejected()
@@ -92,32 +100,40 @@ public class MantleObjectComponent extends IrisMantleComponent {
     }
 
     @ChunkCoordinates
-    private ObjectPlacementSummary placeObjects(MantleWriter writer, RNG rng, int x, int z, IrisBiome biome, IrisRegion region, boolean traceRegen) {
-        int biomeChecked = 0;
-        int biomeTriggered = 0;
-        int regionChecked = 0;
-        int regionTriggered = 0;
+    private ObjectPlacementSummary placeObjects(MantleWriter writer, RNG rng, int x, int z, IrisBiome surfaceBiome, IrisBiome caveBiome, IrisRegion region, boolean traceRegen) {
+        int biomeSurfaceChecked = 0;
+        int biomeSurfaceTriggered = 0;
+        int biomeCaveChecked = 0;
+        int biomeCaveTriggered = 0;
+        int regionSurfaceChecked = 0;
+        int regionSurfaceTriggered = 0;
+        int regionCaveChecked = 0;
+        int regionCaveTriggered = 0;
         int attempts = 0;
         int placed = 0;
         int rejected = 0;
         int nullObjects = 0;
         int errors = 0;
+        IrisCaveProfile biomeCaveProfile = resolveCaveProfile(caveBiome.getCaveProfile(), region.getCaveProfile());
+        IrisCaveProfile regionCaveProfile = resolveCaveProfile(region.getCaveProfile(), caveBiome.getCaveProfile());
+        int biomeSurfaceExclusionDepth = resolveSurfaceObjectExclusionDepth(biomeCaveProfile);
+        int regionSurfaceExclusionDepth = resolveSurfaceObjectExclusionDepth(regionCaveProfile);
 
-        for (IrisObjectPlacement i : biome.getSurfaceObjects()) {
-            biomeChecked++;
+        for (IrisObjectPlacement i : surfaceBiome.getSurfaceObjects()) {
+            biomeSurfaceChecked++;
             boolean chance = rng.chance(i.getChance() + rng.d(-0.005, 0.005));
             if (traceRegen) {
                 Iris.info("Regen object placer chance: chunk=" + x + "," + z
-                        + " scope=biome"
+                        + " scope=biome-surface"
                         + " chanceResult=" + chance
                         + " chanceBase=" + i.getChance()
                         + " densityMid=" + i.getDensity()
                         + " objects=" + i.getPlace().size());
             }
             if (chance) {
-                biomeTriggered++;
+                biomeSurfaceTriggered++;
                 try {
-                    ObjectPlacementResult result = placeObject(writer, rng, x << 4, z << 4, i, traceRegen, x, z, "biome");
+                    ObjectPlacementResult result = placeObject(writer, rng, x << 4, z << 4, i, biomeSurfaceExclusionDepth, traceRegen, x, z, "biome-surface");
                     attempts += result.attempts();
                     placed += result.placed();
                     rejected += result.rejected();
@@ -126,7 +142,41 @@ public class MantleObjectComponent extends IrisMantleComponent {
                 } catch (Throwable e) {
                     errors++;
                     Iris.reportError(e);
-                    Iris.error("Failed to place objects in the following biome: " + biome.getName());
+                    Iris.error("Failed to place objects in the following biome: " + surfaceBiome.getName());
+                    Iris.error("Object(s) " + i.getPlace().toString(", ") + " (" + e.getClass().getSimpleName() + ").");
+                    Iris.error("Are these objects missing?");
+                    e.printStackTrace();
+                }
+            }
+        }
+
+        for (IrisObjectPlacement i : caveBiome.getCarvingObjects()) {
+            if (!i.getCarvingSupport().equals(CarvingMode.CARVING_ONLY)) {
+                continue;
+            }
+            biomeCaveChecked++;
+            boolean chance = rng.chance(i.getChance() + rng.d(-0.005, 0.005));
+            if (traceRegen) {
+                Iris.info("Regen object placer chance: chunk=" + x + "," + z
+                        + " scope=biome-cave"
+                        + " chanceResult=" + chance
+                        + " chanceBase=" + i.getChance()
+                        + " densityMid=" + i.getDensity()
+                        + " objects=" + i.getPlace().size());
+            }
+            if (chance) {
+                biomeCaveTriggered++;
+                try {
+                    ObjectPlacementResult result = placeCaveObject(writer, rng, x, z, i, biomeCaveProfile, traceRegen, x, z, "biome-cave");
+                    attempts += result.attempts();
+                    placed += result.placed();
+                    rejected += result.rejected();
+                    nullObjects += result.nullObjects();
+                    errors += result.errors();
+                } catch (Throwable e) {
+                    errors++;
+                    Iris.reportError(e);
+                    Iris.error("Failed to place cave objects in the following biome: " + caveBiome.getName());
                     Iris.error("Object(s) " + i.getPlace().toString(", ") + " (" + e.getClass().getSimpleName() + ").");
                     Iris.error("Are these objects missing?");
                     e.printStackTrace();
@@ -135,20 +185,20 @@ public class MantleObjectComponent extends IrisMantleComponent {
         }
 
         for (IrisObjectPlacement i : region.getSurfaceObjects()) {
-            regionChecked++;
+            regionSurfaceChecked++;
             boolean chance = rng.chance(i.getChance() + rng.d(-0.005, 0.005));
             if (traceRegen) {
                 Iris.info("Regen object placer chance: chunk=" + x + "," + z
-                        + " scope=region"
+                        + " scope=region-surface"
                         + " chanceResult=" + chance
                         + " chanceBase=" + i.getChance()
                         + " densityMid=" + i.getDensity()
                         + " objects=" + i.getPlace().size());
             }
             if (chance) {
-                regionTriggered++;
+                regionSurfaceTriggered++;
                 try {
-                    ObjectPlacementResult result = placeObject(writer, rng, x << 4, z << 4, i, traceRegen, x, z, "region");
+                    ObjectPlacementResult result = placeObject(writer, rng, x << 4, z << 4, i, regionSurfaceExclusionDepth, traceRegen, x, z, "region-surface");
                     attempts += result.attempts();
                     placed += result.placed();
                     rejected += result.rejected();
@@ -165,11 +215,49 @@ public class MantleObjectComponent extends IrisMantleComponent {
             }
         }
 
+        for (IrisObjectPlacement i : region.getCarvingObjects()) {
+            if (!i.getCarvingSupport().equals(CarvingMode.CARVING_ONLY)) {
+                continue;
+            }
+            regionCaveChecked++;
+            boolean chance = rng.chance(i.getChance() + rng.d(-0.005, 0.005));
+            if (traceRegen) {
+                Iris.info("Regen object placer chance: chunk=" + x + "," + z
+                        + " scope=region-cave"
+                        + " chanceResult=" + chance
+                        + " chanceBase=" + i.getChance()
+                        + " densityMid=" + i.getDensity()
+                        + " objects=" + i.getPlace().size());
+            }
+            if (chance) {
+                regionCaveTriggered++;
+                try {
+                    ObjectPlacementResult result = placeCaveObject(writer, rng, x, z, i, regionCaveProfile, traceRegen, x, z, "region-cave");
+                    attempts += result.attempts();
+                    placed += result.placed();
+                    rejected += result.rejected();
+                    nullObjects += result.nullObjects();
+                    errors += result.errors();
+                } catch (Throwable e) {
+                    errors++;
+                    Iris.reportError(e);
+                    Iris.error("Failed to place cave objects in the following region: " + region.getName());
+                    Iris.error("Object(s) " + i.getPlace().toString(", ") + " (" + e.getClass().getSimpleName() + ").");
+                    Iris.error("Are these objects missing?");
+                    e.printStackTrace();
+                }
+            }
+        }
+
         return new ObjectPlacementSummary(
-                biomeChecked,
-                biomeTriggered,
-                regionChecked,
-                regionTriggered,
+                biomeSurfaceChecked,
+                biomeSurfaceTriggered,
+                biomeCaveChecked,
+                biomeCaveTriggered,
+                regionSurfaceChecked,
+                regionSurfaceTriggered,
+                regionCaveChecked,
+                regionCaveTriggered,
                 attempts,
                 placed,
                 rejected,
@@ -185,6 +273,7 @@ public class MantleObjectComponent extends IrisMantleComponent {
             int x,
             int z,
             IrisObjectPlacement objectPlacement,
+            int surfaceObjectExclusionDepth,
             boolean traceRegen,
             int chunkX,
             int chunkZ,
@@ -213,6 +302,11 @@ public class MantleObjectComponent extends IrisMantleComponent {
             }
             int xx = rng.i(x, x + 15);
             int zz = rng.i(z, z + 15);
+            int surfaceObjectExclusionRadius = resolveSurfaceObjectExclusionRadius(v);
+            if (surfaceObjectExclusionDepth > 0 && hasSurfaceCarveExposure(writer, xx, zz, surfaceObjectExclusionDepth, surfaceObjectExclusionRadius)) {
+                rejected++;
+                continue;
+            }
             int id = rng.i(0, Integer.MAX_VALUE);
             try {
                 int result = v.place(xx, -1, zz, writer, objectPlacement, rng, (b, data) -> {
@@ -253,16 +347,270 @@ public class MantleObjectComponent extends IrisMantleComponent {
         return new ObjectPlacementResult(attempts, placed, rejected, nullObjects, errors);
     }
 
+    @ChunkCoordinates
+    private ObjectPlacementResult placeCaveObject(
+            MantleWriter writer,
+            RNG rng,
+            int chunkX,
+            int chunkZ,
+            IrisObjectPlacement objectPlacement,
+            IrisCaveProfile caveProfile,
+            boolean traceRegen,
+            int metricChunkX,
+            int metricChunkZ,
+            String scope
+    ) {
+        int attempts = 0;
+        int placed = 0;
+        int rejected = 0;
+        int nullObjects = 0;
+        int errors = 0;
+        int minX = chunkX << 4;
+        int minZ = chunkZ << 4;
+        int density = objectPlacement.getDensity(rng, minX, minZ, getData());
+        KMap<Long, KList<Integer>> anchorCache = new KMap<>();
+        IrisCaveAnchorMode anchorMode = resolveAnchorMode(objectPlacement, caveProfile);
+        int anchorScanStep = resolveAnchorScanStep(caveProfile);
+        int objectMinDepthBelowSurface = resolveObjectMinDepthBelowSurface(caveProfile);
+        int anchorSearchAttempts = resolveAnchorSearchAttempts(caveProfile);
+
+        for (int i = 0; i < density; i++) {
+            attempts++;
+            IrisObject object = objectPlacement.getScale().get(rng, objectPlacement.getObject(getComplex(), rng));
+            if (object == null) {
+                nullObjects++;
+                if (traceRegen) {
+                    Iris.warn("Regen cave object placement null object: chunk=" + metricChunkX + "," + metricChunkZ
+                            + " scope=" + scope
+                            + " densityIndex=" + i
+                            + " density=" + density
+                            + " placementKeys=" + objectPlacement.getPlace().toString(","));
+                }
+                continue;
+            }
+
+            int x = 0;
+            int z = 0;
+            int y = -1;
+            for (int search = 0; search < anchorSearchAttempts; search++) {
+                int candidateX = rng.i(minX, minX + 15);
+                int candidateZ = rng.i(minZ, minZ + 15);
+                int candidateY = findCaveAnchorY(writer, rng, candidateX, candidateZ, anchorMode, anchorScanStep, objectMinDepthBelowSurface, anchorCache);
+                if (candidateY < 0) {
+                    continue;
+                }
+
+                x = candidateX;
+                z = candidateZ;
+                y = candidateY;
+                break;
+            }
+
+            if (y < 0) {
+                rejected++;
+                continue;
+            }
+
+            int id = rng.i(0, Integer.MAX_VALUE);
+
+            try {
+                int result = object.place(x, y, z, writer, objectPlacement, rng, (b, data) -> {
+                    writer.setData(b.getX(), b.getY(), b.getZ(), object.getLoadKey() + "@" + id);
+                    if (objectPlacement.isDolphinTarget() && objectPlacement.isUnderwater() && B.isStorageChest(data)) {
+                        writer.setData(b.getX(), b.getY(), b.getZ(), MatterStructurePOI.BURIED_TREASURE);
+                    }
+                }, null, getData());
+
+                if (result >= 0) {
+                    placed++;
+                } else {
+                    rejected++;
+                }
+
+                if (traceRegen) {
+                    Iris.info("Regen cave object placement result: chunk=" + metricChunkX + "," + metricChunkZ
+                            + " scope=" + scope
+                            + " object=" + object.getLoadKey()
+                            + " resultY=" + result
+                            + " anchorY=" + y
+                            + " px=" + x
+                            + " pz=" + z
+                            + " densityIndex=" + i
+                            + " density=" + density);
+                }
+            } catch (Throwable e) {
+                errors++;
+                Iris.reportError(e);
+                Iris.error("Regen cave object placement exception: chunk=" + metricChunkX + "," + metricChunkZ
+                        + " scope=" + scope
+                        + " object=" + object.getLoadKey()
+                        + " densityIndex=" + i
+                        + " density=" + density
+                        + " error=" + e.getClass().getSimpleName() + ":" + e.getMessage());
+            }
+        }
+
+        return new ObjectPlacementResult(attempts, placed, rejected, nullObjects, errors);
+    }
+
+    private int findCaveAnchorY(MantleWriter writer, RNG rng, int x, int z, IrisCaveAnchorMode anchorMode, int anchorScanStep, int objectMinDepthBelowSurface, KMap<Long, KList<Integer>> anchorCache) {
+        long key = Cache.key(x, z);
+        KList<Integer> anchors = anchorCache.computeIfAbsent(key, (k) -> scanCaveAnchorColumn(writer, anchorMode, anchorScanStep, objectMinDepthBelowSurface, x, z));
+        if (anchors.isEmpty()) {
+            return -1;
+        }
+
+        if (anchors.size() == 1) {
+            return anchors.get(0);
+        }
+
+        return anchors.get(rng.i(0, anchors.size() - 1));
+    }
+
+    private KList<Integer> scanCaveAnchorColumn(MantleWriter writer, IrisCaveAnchorMode anchorMode, int anchorScanStep, int objectMinDepthBelowSurface, int x, int z) {
+        KList<Integer> anchors = new KList<>();
+        int height = getEngineMantle().getEngine().getHeight();
+        int step = Math.max(1, anchorScanStep);
+        int surfaceY = getEngineMantle().getEngine().getHeight(x, z);
+        int maxAnchorY = Math.min(height - 1, surfaceY - Math.max(0, objectMinDepthBelowSurface));
+        if (maxAnchorY <= 1) {
+            return anchors;
+        }
+
+        for (int y = 1; y < maxAnchorY; y += step) {
+            if (!writer.isCarved(x, y, z)) {
+                continue;
+            }
+
+            boolean solidBelow = y <= 0 || !writer.isCarved(x, y - 1, z);
+            boolean solidAbove = y >= (height - 1) || !writer.isCarved(x, y + 1, z);
+            if (matchesCaveAnchor(anchorMode, solidBelow, solidAbove)) {
+                anchors.add(y);
+            }
+        }
+
+        return anchors;
+    }
+
+    private boolean matchesCaveAnchor(IrisCaveAnchorMode anchorMode, boolean solidBelow, boolean solidAbove) {
+        return switch (anchorMode) {
+            case PROFILE_DEFAULT, FLOOR -> solidBelow;
+            case CEILING -> solidAbove;
+            case CENTER -> !solidBelow && !solidAbove;
+            case ANY -> true;
+        };
+    }
+
+    private IrisCaveProfile resolveCaveProfile(IrisCaveProfile preferred, IrisCaveProfile secondary) {
+        IrisCaveProfile dimensionProfile = getDimension().getCaveProfile();
+        if (preferred != null && preferred.isEnabled()) {
+            return preferred;
+        }
+
+        if (secondary != null && secondary.isEnabled()) {
+            return secondary;
+        }
+
+        if (dimensionProfile != null) {
+            return dimensionProfile;
+        }
+
+        return new IrisCaveProfile();
+    }
+
+    private IrisCaveAnchorMode resolveAnchorMode(IrisObjectPlacement objectPlacement, IrisCaveProfile caveProfile) {
+        IrisCaveAnchorMode placementMode = objectPlacement.getCaveAnchorMode();
+        if (placementMode != null && !placementMode.equals(IrisCaveAnchorMode.PROFILE_DEFAULT)) {
+            return placementMode;
+        }
+
+        if (caveProfile == null) {
+            return IrisCaveAnchorMode.FLOOR;
+        }
+
+        IrisCaveAnchorMode profileMode = caveProfile.getDefaultObjectAnchor();
+        if (profileMode == null || profileMode.equals(IrisCaveAnchorMode.PROFILE_DEFAULT)) {
+            return IrisCaveAnchorMode.FLOOR;
+        }
+
+        return profileMode;
+    }
+
+    private int resolveAnchorScanStep(IrisCaveProfile caveProfile) {
+        if (caveProfile == null) {
+            return 1;
+        }
+
+        return Math.max(1, caveProfile.getAnchorScanStep());
+    }
+
+    private int resolveObjectMinDepthBelowSurface(IrisCaveProfile caveProfile) {
+        if (caveProfile == null) {
+            return 6;
+        }
+
+        return Math.max(0, caveProfile.getObjectMinDepthBelowSurface());
+    }
+
+    private int resolveSurfaceObjectExclusionDepth(IrisCaveProfile caveProfile) {
+        if (caveProfile == null) {
+            return 5;
+        }
+
+        return Math.max(0, caveProfile.getSurfaceObjectExclusionDepth());
+    }
+
+    private int resolveSurfaceObjectExclusionRadius(IrisObject object) {
+        if (object == null) {
+            return 1;
+        }
+
+        int maxDimension = Math.max(object.getW(), object.getD());
+        return Math.max(1, Math.min(8, Math.floorDiv(Math.max(1, maxDimension), 2)));
+    }
+
+    private int resolveAnchorSearchAttempts(IrisCaveProfile caveProfile) {
+        if (caveProfile == null) {
+            return 6;
+        }
+
+        return Math.max(1, caveProfile.getAnchorSearchAttempts());
+    }
+
+    private boolean hasSurfaceCarveExposure(MantleWriter writer, int x, int z, int depth, int radius) {
+        int horizontalRadius = Math.max(0, radius);
+        for (int dx = -horizontalRadius; dx <= horizontalRadius; dx++) {
+            for (int dz = -horizontalRadius; dz <= horizontalRadius; dz++) {
+                int columnX = x + dx;
+                int columnZ = z + dz;
+                int surfaceY = getEngineMantle().getEngine().getHeight(columnX, columnZ, true);
+                int fromY = Math.max(1, surfaceY - Math.max(0, depth));
+                int toY = Math.min(getEngineMantle().getEngine().getHeight() - 1, surfaceY + 1);
+                for (int y = fromY; y <= toY; y++) {
+                    if (writer.isCarved(columnX, y, columnZ)) {
+                        return true;
+                    }
+                }
+            }
+        }
+
+        return false;
+    }
+
     private boolean isRegenTraceThread() {
         return Thread.currentThread().getName().startsWith("Iris-Regen-")
                 && IrisSettings.get().getGeneral().isDebug();
     }
 
     private record ObjectPlacementSummary(
-            int biomePlacersChecked,
-            int biomePlacersTriggered,
-            int regionPlacersChecked,
-            int regionPlacersTriggered,
+            int biomeSurfacePlacersChecked,
+            int biomeSurfacePlacersTriggered,
+            int biomeCavePlacersChecked,
+            int biomeCavePlacersTriggered,
+            int regionSurfacePlacersChecked,
+            int regionSurfacePlacersTriggered,
+            int regionCavePlacersChecked,
+            int regionCavePlacersTriggered,
             int objectAttempts,
             int objectPlaced,
             int objectRejected,

core/src/main/java/art/arcane/iris/engine/modifier/IrisCarveModifier.java

@@ -108,6 +108,8 @@ public class IrisCarveModifier extends EngineAssignedModifier<BlockData> {
                 output.set(rx, yy, rz, context.getFluid().get(rx, rz));
             } else if (c.isLava()) {
                 output.set(rx, yy, rz, LAVA);
+            } else if (c.getLiquid() == 3) {
+                output.set(rx, yy, rz, AIR);
             } else {
                 if (getEngine().getDimension().getCaveLavaHeight() > yy) {
                     output.set(rx, yy, rz, LAVA);

core/src/main/java/art/arcane/iris/engine/object/IrisBiome.java

@@ -102,6 +102,8 @@ public class IrisBiome extends IrisRegistrant implements IRare {
     private int lockLayersMax = 7;
     @Desc("Carving configuration for the dimension")
     private IrisCarving carving = new IrisCarving();
+    @Desc("Profile-driven 3D cave configuration")
+    private IrisCaveProfile caveProfile = new IrisCaveProfile();
     @Desc("Configuration of fluid bodies such as rivers & lakes")
     private IrisFluidBodies fluidBodies = new IrisFluidBodies();
     @MinNumber(1)
@@ -194,12 +196,21 @@ public class IrisBiome extends IrisRegistrant implements IRare {
     }
 
     public double getGenLinkMax(String loadKey, Engine engine) {
+        if (loadKey == null || loadKey.isBlank()) {
+            return 0;
+        }
+
         Integer v = genCacheMax.aquire(() ->
         {
             KMap<String, Integer> l = new KMap<>();
 
             for (IrisBiomeGeneratorLink i : getGenerators()) {
-                l.put(i.getGenerator(), i.getMax());
+                String generatorKey = i.getGenerator();
+                if (generatorKey == null || generatorKey.isBlank()) {
+                    continue;
+                }
+
+                l.put(generatorKey, i.getMax());
 
             }
 
@@ -210,12 +221,21 @@ public class IrisBiome extends IrisRegistrant implements IRare {
     }
 
     public double getGenLinkMin(String loadKey, Engine engine) {
+        if (loadKey == null || loadKey.isBlank()) {
+            return 0;
+        }
+
         Integer v = genCacheMin.aquire(() ->
         {
             KMap<String, Integer> l = new KMap<>();
 
             for (IrisBiomeGeneratorLink i : getGenerators()) {
-                l.put(i.getGenerator(), i.getMin());
+                String generatorKey = i.getGenerator();
+                if (generatorKey == null || generatorKey.isBlank()) {
+                    continue;
+                }
+
+                l.put(generatorKey, i.getMin());
             }
 
             return l;
@@ -225,12 +245,21 @@ public class IrisBiome extends IrisRegistrant implements IRare {
     }
 
     public IrisBiomeGeneratorLink getGenLink(String loadKey) {
+        if (loadKey == null || loadKey.isBlank()) {
+            return null;
+        }
+
         return genCache.aquire(() ->
         {
             KMap<String, IrisBiomeGeneratorLink> l = new KMap<>();
 
             for (IrisBiomeGeneratorLink i : getGenerators()) {
-                l.put(i.getGenerator(), i);
+                String generatorKey = i.getGenerator();
+                if (generatorKey == null || generatorKey.isBlank()) {
+                    continue;
+                }
+
+                l.put(generatorKey, i);
             }
 
             return l;

core/src/main/java/art/arcane/iris/engine/object/IrisBiomeGeneratorLink.java

@@ -52,12 +52,21 @@ public class IrisBiomeGeneratorLink {
 
     public IrisGenerator getCachedGenerator(DataProvider g) {
         return gen.aquire(() -> {
-            IrisGenerator gen = g.getData().getGeneratorLoader().load(getGenerator());
+            String generatorKey = getGenerator();
+            if (generatorKey == null || generatorKey.isBlank()) {
+                generatorKey = "default";
+            }
+
+            IrisGenerator gen = g.getData().getGeneratorLoader().load(generatorKey);
 
             if (gen == null) {
                 gen = new IrisGenerator();
             }
 
+            if (gen.getLoadKey() == null || gen.getLoadKey().isBlank()) {
+                gen.setLoadKey(generatorKey);
+            }
+
             return gen;
         });
     }

core/src/main/java/art/arcane/iris/engine/object/IrisCaveAnchorMode.java

@@ -0,0 +1,21 @@
+package art.arcane.iris.engine.object;
+
+import art.arcane.iris.engine.object.annotations.Desc;
+
+@Desc("Defines which carved-space anchor to target for cave object placement.")
+public enum IrisCaveAnchorMode {
+    @Desc("Use the active cave profile default anchor mode.")
+    PROFILE_DEFAULT,
+
+    @Desc("Target cave floor anchors where carved space has solid support below.")
+    FLOOR,
+
+    @Desc("Target cave ceiling anchors where carved space has solid support above.")
+    CEILING,
+
+    @Desc("Target carved positions with no immediate solid support above or below.")
+    CENTER,
+
+    @Desc("Target any carved-space anchor.")
+    ANY
+}

core/src/main/java/art/arcane/iris/engine/object/IrisCaveFieldModule.java

@@ -0,0 +1,36 @@
+package art.arcane.iris.engine.object;
+
+import art.arcane.iris.engine.object.annotations.Desc;
+import art.arcane.iris.engine.object.annotations.MaxNumber;
+import art.arcane.iris.engine.object.annotations.MinNumber;
+import art.arcane.iris.engine.object.annotations.Snippet;
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+import lombok.experimental.Accessors;
+
+@Snippet("cave-field-module")
+@Accessors(chain = true)
+@NoArgsConstructor
+@AllArgsConstructor
+@Desc("Represents a modular cave-density layer.")
+@Data
+public class IrisCaveFieldModule {
+    @Desc("Density style used by this module.")
+    private IrisGeneratorStyle style = NoiseStyle.CELLULAR_IRIS_DOUBLE.style();
+
+    @MinNumber(0)
+    @Desc("Layer contribution multiplier.")
+    private double weight = 1;
+
+    @MinNumber(-1)
+    @MaxNumber(1)
+    @Desc("Threshold offset applied to this layer before blending.")
+    private double threshold = 0;
+
+    @Desc("Vertical bounds where this module can contribute.")
+    private IrisRange verticalRange = new IrisRange(0, 384);
+
+    @Desc("Invert this module before weighting.")
+    private boolean invert = false;
+}

core/src/main/java/art/arcane/iris/engine/object/IrisCaveProfile.java

@@ -0,0 +1,127 @@
+package art.arcane.iris.engine.object;
+
+import art.arcane.iris.engine.object.annotations.ArrayType;
+import art.arcane.iris.engine.object.annotations.Desc;
+import art.arcane.iris.engine.object.annotations.MaxNumber;
+import art.arcane.iris.engine.object.annotations.MinNumber;
+import art.arcane.iris.engine.object.annotations.Snippet;
+import art.arcane.volmlib.util.collection.KList;
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+import lombok.experimental.Accessors;
+
+@Snippet("cave-profile")
+@Accessors(chain = true)
+@NoArgsConstructor
+@AllArgsConstructor
+@Desc("Represents a configurable 3D cave profile.")
+@Data
+public class IrisCaveProfile {
+    @Desc("Enable profile-driven cave carving.")
+    private boolean enabled = false;
+
+    @Desc("Global vertical bounds for profile cave carving.")
+    private IrisRange verticalRange = new IrisRange(0, 384);
+
+    @Desc("Base density style for cave field generation.")
+    private IrisGeneratorStyle baseDensityStyle = NoiseStyle.CELLULAR_IRIS_DOUBLE.style();
+
+    @Desc("Detail density style blended into base caves.")
+    private IrisGeneratorStyle detailDensityStyle = new IrisGeneratorStyle(NoiseStyle.SIMPLEX);
+
+    @Desc("Warp style used to distort cave coordinates.")
+    private IrisGeneratorStyle warpStyle = new IrisGeneratorStyle(NoiseStyle.FLAT);
+
+    @MinNumber(0)
+    @Desc("Base cave field multiplier.")
+    private double baseWeight = 1;
+
+    @MinNumber(0)
+    @Desc("Detail cave field multiplier.")
+    private double detailWeight = 0.35;
+
+    @MinNumber(0)
+    @Desc("Coordinate warp strength for cave fields.")
+    private double warpStrength = 0;
+
+    @Desc("Threshold range used for carve cutoff decisions.")
+    private IrisStyledRange densityThreshold = new IrisStyledRange(-0.2, 0.2, NoiseStyle.CELLULAR_IRIS_DOUBLE.style());
+
+    @MinNumber(0)
+    @MaxNumber(1)
+    @Desc("Extra threshold bias subtracted from sampled threshold before carve tests.")
+    private double thresholdBias = 0.16;
+
+    @MinNumber(1)
+    @MaxNumber(8)
+    @Desc("Vertical sample step used while evaluating cave density.")
+    private int sampleStep = 2;
+
+    @MinNumber(0)
+    @MaxNumber(64)
+    @Desc("Minimum solid clearance below terrain surface where carving may occur.")
+    private int surfaceClearance = 4;
+
+    @Desc("Allow profile-driven cave carving to break through terrain surface in selected columns.")
+    private boolean allowSurfaceBreak = true;
+
+    @Desc("Noise style used to decide where surface-breaking cave columns are allowed.")
+    private IrisGeneratorStyle surfaceBreakStyle = new IrisGeneratorStyle(NoiseStyle.SIMPLEX).zoomed(0.08);
+
+    @MinNumber(-1)
+    @MaxNumber(1)
+    @Desc("Minimum signed surface-break noise value required before near-surface carving is allowed.")
+    private double surfaceBreakNoiseThreshold = 0.62;
+
+    @MinNumber(0)
+    @MaxNumber(64)
+    @Desc("Near-surface depth window used for surface-break carve logic.")
+    private int surfaceBreakDepth = 18;
+
+    @MinNumber(0)
+    @MaxNumber(1)
+    @Desc("Additional threshold boost applied while carving in the surface-break depth window.")
+    private double surfaceBreakThresholdBoost = 0.2;
+
+    @MinNumber(0)
+    @MaxNumber(64)
+    @Desc("Minimum depth below terrain surface required for cave-only object anchor placement.")
+    private int objectMinDepthBelowSurface = 6;
+
+    @MinNumber(0)
+    @MaxNumber(32)
+    @Desc("Skip surface-object placement when carved cells exist this many blocks below terrain surface.")
+    private int surfaceObjectExclusionDepth = 5;
+
+    @ArrayType(type = IrisCaveFieldModule.class, min = 1)
+    @Desc("Additional layered cave-density modules.")
+    private KList<IrisCaveFieldModule> modules = new KList<>();
+
+    @Desc("Default cave anchor mode for cave-only object placement.")
+    private IrisCaveAnchorMode defaultObjectAnchor = IrisCaveAnchorMode.FLOOR;
+
+    @MinNumber(1)
+    @MaxNumber(8)
+    @Desc("Vertical scan step used while searching cave anchors.")
+    private int anchorScanStep = 1;
+
+    @MinNumber(1)
+    @MaxNumber(64)
+    @Desc("Maximum random column retries while searching a valid cave object anchor in the chunk.")
+    private int anchorSearchAttempts = 6;
+
+    @Desc("Allow cave water placement below fluid level.")
+    private boolean allowWater = true;
+
+    @MinNumber(0)
+    @MaxNumber(64)
+    @Desc("Minimum depth below terrain surface required before cave water may be placed.")
+    private int waterMinDepthBelowSurface = 12;
+
+    @Desc("Require solid floor support below cave water to reduce cascading cave waterfalls.")
+    private boolean waterRequiresFloor = true;
+
+    @Desc("Allow cave lava placement based on lava height.")
+    private boolean allowLava = true;
+}

core/src/main/java/art/arcane/iris/engine/object/IrisDimension.java

@@ -142,10 +142,12 @@ public class IrisDimension extends IrisRegistrant {
     private boolean postProcessingSlabs = true;
     @Desc("Add painted walls in post processing")
     private boolean postProcessingWalls = true;
-    @Desc("Carving configuration for the dimension")
-    private IrisCarving carving = new IrisCarving();
-    @Desc("Configuration of fluid bodies such as rivers & lakes")
-    private IrisFluidBodies fluidBodies = new IrisFluidBodies();
+    @Desc("Carving configuration for the dimension")
+    private IrisCarving carving = new IrisCarving();
+    @Desc("Profile-driven 3D cave configuration")
+    private IrisCaveProfile caveProfile = new IrisCaveProfile();
+    @Desc("Configuration of fluid bodies such as rivers & lakes")
+    private IrisFluidBodies fluidBodies = new IrisFluidBodies();
     @Desc("forceConvertTo320Height")
     private Boolean forceConvertTo320Height = false;
     @Desc("The world environment")

core/src/main/java/art/arcane/iris/engine/object/IrisObject.java

@@ -689,10 +689,7 @@ public class IrisObject extends IrisRegistrant {
             // todo Convert this to a dedicated mode.
             y = (getH() + 1) + rty;
             if (!config.isForcePlace()) {
-                if (placer.isCarved(x, y, z) ||
-                        placer.isCarved(x, y - 1, z) ||
-                        placer.isCarved(x, y - 2, z) ||
-                        placer.isCarved(x, y - 3, z)) {
+                if (shouldBailForCarvingAnchor(placer, config, x, y, z)) {
                     bail = true;
                 }
             }
@@ -700,7 +697,7 @@ public class IrisObject extends IrisRegistrant {
             if (config.getMode().equals(ObjectPlaceMode.CENTER_HEIGHT) || config.getMode() == ObjectPlaceMode.CENTER_STILT) {
                 y = (c != null ? c.getSurface() : placer.getHighest(x, z, getLoader(), config.isUnderwater())) + rty;
                 if (!config.isForcePlace()) {
-                    if (placer.isCarved(x, y, z) || placer.isCarved(x, y - 1, z) || placer.isCarved(x, y - 2, z) || placer.isCarved(x, y - 3, z)) {
+                    if (shouldBailForCarvingAnchor(placer, config, x, y, z)) {
                         bail = true;
                     }
                 }
@@ -717,7 +714,7 @@ public class IrisObject extends IrisRegistrant {
                     for (int ii = minZ; ii <= maxZ; ii++) {
                         int h = placer.getHighest(i, ii, getLoader(), config.isUnderwater()) + rty;
                         if (!config.isForcePlace()) {
-                            if (placer.isCarved(i, h, ii) || placer.isCarved(i, h - 1, ii) || placer.isCarved(i, h - 2, ii) || placer.isCarved(i, h - 3, ii)) {
+                            if (shouldBailForCarvingAnchor(placer, config, i, h, ii)) {
                                 bail = true;
                                 break;
                             }
@@ -743,7 +740,7 @@ public class IrisObject extends IrisRegistrant {
                     for (int ii = minZ; ii <= maxZ; ii += Math.abs(zRadius) + 1) {
                         int h = placer.getHighest(i, ii, getLoader(), config.isUnderwater()) + rty;
                         if (!config.isForcePlace()) {
-                            if (placer.isCarved(i, h, ii) || placer.isCarved(i, h - 1, ii) || placer.isCarved(i, h - 2, ii) || placer.isCarved(i, h - 3, ii)) {
+                            if (shouldBailForCarvingAnchor(placer, config, i, h, ii)) {
                                 bail = true;
                                 break;
                             }
@@ -767,7 +764,7 @@ public class IrisObject extends IrisRegistrant {
                     for (int ii = minZ; ii <= maxZ; ii++) {
                         int h = placer.getHighest(i, ii, getLoader(), config.isUnderwater()) + rty;
                         if (!config.isForcePlace()) {
-                            if (placer.isCarved(i, h, ii) || placer.isCarved(i, h - 1, ii) || placer.isCarved(i, h - 2, ii) || placer.isCarved(i, h - 3, ii)) {
+                            if (shouldBailForCarvingAnchor(placer, config, i, h, ii)) {
                                 bail = true;
                                 break;
                             }
@@ -795,7 +792,7 @@ public class IrisObject extends IrisRegistrant {
                     for (int ii = minZ; ii <= maxZ; ii += Math.abs(zRadius) + 1) {
                         int h = placer.getHighest(i, ii, getLoader(), config.isUnderwater()) + rty;
                         if (!config.isForcePlace()) {
-                            if (placer.isCarved(i, h, ii) || placer.isCarved(i, h - 1, ii) || placer.isCarved(i, h - 2, ii) || placer.isCarved(i, h - 3, ii)) {
+                            if (shouldBailForCarvingAnchor(placer, config, i, h, ii)) {
                                 bail = true;
                                 break;
                             }
@@ -808,7 +805,7 @@ public class IrisObject extends IrisRegistrant {
             } else if (config.getMode().equals(ObjectPlaceMode.PAINT)) {
                 y = placer.getHighest(x, z, getLoader(), config.isUnderwater()) + rty;
                 if (!config.isForcePlace()) {
-                    if (placer.isCarved(x, y, z) || placer.isCarved(x, y - 1, z) || placer.isCarved(x, y - 2, z) || placer.isCarved(x, y - 3, z)) {
+                    if (shouldBailForCarvingAnchor(placer, config, x, y, z)) {
                         bail = true;
                     }
                 }
@@ -816,7 +813,7 @@ public class IrisObject extends IrisRegistrant {
         } else {
             y = yv;
             if (!config.isForcePlace()) {
-                if (placer.isCarved(x, y, z) || placer.isCarved(x, y - 1, z) || placer.isCarved(x, y - 2, z) || placer.isCarved(x, y - 3, z)) {
+                if (shouldBailForCarvingAnchor(placer, config, x, y, z)) {
                     bail = true;
                 }
             }
@@ -825,7 +822,7 @@ public class IrisObject extends IrisRegistrant {
         if (yv >= 0 && config.isBottom()) {
             y += Math.floorDiv(h, 2);
             if (!config.isForcePlace()) {
-                bail = placer.isCarved(x, y, z) || placer.isCarved(x, y - 1, z) || placer.isCarved(x, y - 2, z) || placer.isCarved(x, y - 3, z);
+                bail = shouldBailForCarvingAnchor(placer, config, x, y, z);
             }
         }
 
@@ -1160,6 +1157,23 @@ public class IrisObject extends IrisRegistrant {
         return y;
     }
 
+    private boolean shouldBailForCarvingAnchor(IObjectPlacer placer, IrisObjectPlacement placement, int x, int y, int z) {
+        boolean carved = isCarvedAnchor(placer, x, y, z);
+        CarvingMode carvingMode = placement.getCarvingSupport();
+        return switch (carvingMode) {
+            case SURFACE_ONLY -> carved;
+            case CARVING_ONLY -> !carved;
+            case ANYWHERE -> false;
+        };
+    }
+
+    private boolean isCarvedAnchor(IObjectPlacer placer, int x, int y, int z) {
+        return placer.isCarved(x, y, z)
+                || placer.isCarved(x, y - 1, z)
+                || placer.isCarved(x, y - 2, z)
+                || placer.isCarved(x, y - 3, z);
+    }
+
     public IrisObject rotateCopy(IrisObjectRotation rt) {
         IrisObject copy = copy();
         copy.rotate(rt, 0, 0, 0);

core/src/main/java/art/arcane/iris/engine/object/IrisObjectPlacement.java

@@ -99,6 +99,8 @@ public class IrisObjectPlacement {
     private boolean underwater = false;
     @Desc("If set to true, objects will place in carvings (such as underground) or under an overhang.")
     private CarvingMode carvingSupport = CarvingMode.SURFACE_ONLY;
+    @Desc("When carving placement is enabled, select which carved-space anchor this placement targets.")
+    private IrisCaveAnchorMode caveAnchorMode = IrisCaveAnchorMode.PROFILE_DEFAULT;
     @Desc("If this is defined, this object wont place on the terrain heightmap, but instead on this virtual heightmap")
     private IrisNoiseGenerator heightmap;
     @Desc("If set to true, Iris will try to fill the insides of 'rooms' and 'pockets' where air should fit based off of raytrace checks. This prevents a village house placing in an area where a tree already exists, and instead replaces the parts of the tree where the interior of the structure is. \n\nThis operation does not affect warmed-up generation speed however it does slow down loading objects.")
@@ -165,6 +167,7 @@ public class IrisObjectPlacement {
         p.setOnwater(onwater);
         p.setSmartBore(smartBore);
         p.setCarvingSupport(carvingSupport);
+        p.setCaveAnchorMode(caveAnchorMode);
         p.setUnderwater(underwater);
         p.setBoreExtendMaxY(boreExtendMaxY);
         p.setBoreExtendMinY(boreExtendMinY);

core/src/main/java/art/arcane/iris/engine/object/IrisRegion.java

@@ -114,6 +114,8 @@ public class IrisRegion extends IrisRegistrant implements IRare {
     private double caveBiomeZoom = 1;
     @Desc("Carving configuration for the dimension")
     private IrisCarving carving = new IrisCarving();
+    @Desc("Profile-driven 3D cave configuration")
+    private IrisCaveProfile caveProfile = new IrisCaveProfile();
     @Desc("Configuration of fluid bodies such as rivers & lakes")
     private IrisFluidBodies fluidBodies = new IrisFluidBodies();
     @RegistryListResource(IrisBiome.class)

nms/v1_21_R7/src/main/java/art/arcane/iris/core/nms/v1_21_R7/CustomBiomeSource.java

@@ -203,8 +203,15 @@ public class CustomBiomeSource extends BiomeSource {
 
         int blockX = x << 2;
         int blockZ = z << 2;
-        int blockY = (y - engine.getMinHeight()) << 2;
-        IrisBiome irisBiome = engine.getComplex().getTrueBiomeStream().get(blockX, blockZ);
+        int blockY = y << 2;
+        int surfaceY = engine.getComplex().getHeightStream().get(blockX, blockZ).intValue();
+        boolean underground = blockY <= surfaceY - 2;
+        IrisBiome irisBiome = underground
+                ? engine.getComplex().getCaveBiomeStream().get(blockX, blockZ)
+                : engine.getComplex().getTrueBiomeStream().get(blockX, blockZ);
+        if (irisBiome == null && underground) {
+            irisBiome = engine.getComplex().getTrueBiomeStream().get(blockX, blockZ);
+        }
         if (irisBiome == null) {
             return getFallbackBiome();
         }
@@ -226,7 +233,9 @@ public class CustomBiomeSource extends BiomeSource {
             return getFallbackBiome();
         }
 
-        org.bukkit.block.Biome vanillaBiome = irisBiome.getSkyBiome(noiseRng, blockX, blockY, blockZ);
+        org.bukkit.block.Biome vanillaBiome = underground
+                ? irisBiome.getGroundBiome(noiseRng, blockX, blockY, blockZ)
+                : irisBiome.getSkyBiome(noiseRng, blockX, blockY, blockZ);
         Holder<Biome> holder = NMSBinding.biomeToBiomeBase(biomeRegistry, vanillaBiome);
         if (holder != null) {
             return holder;