Sample terrain height for ERODE_STILT

core/src/main/java/art/arcane/iris/structure/object/PlacementModuleStilt.java

@@ -36,20 +36,13 @@ public final class PlacementModuleStilt implements PlacementModule {
         PlacementModule height = switch (mode) {
             case CENTER, ORGANIC, CEILING -> new PlacementModuleCenterHeight();
             case MIN -> new PlacementModuleHeight(PlacementModuleHeight.Mode.MIN, fast);
-            case DEFAULT -> new PlacementModuleHeight(PlacementModuleHeight.Mode.MAX, fast);
+            case DEFAULT, ERODE -> new PlacementModuleHeight(PlacementModuleHeight.Mode.MAX, fast);
-            case ERODE -> PlacementModuleStilt::installUnsampledHeight;
         };
         height.install(lifecycle);
         lifecycle.add(FILL, PlacementStage.AFTER_BLOCKS, this::fill, PlacementModuleAnchor.HEIGHT,
                 PlacementModuleBlocks.COMPLETE, PlacementModuleTreeGrounding.ROOTS);
     }
 
-    /** The legacy runner never sampled terrain for ERODE_STILT, so surface placements keep the unset height. */
-    private static void installUnsampledHeight(PlacementLifecycleBuilder lifecycle) {
-        PlacementModuleAnchor.install(lifecycle, (context, state, ignored) -> {
-        });
-    }
-
     private static StiltLayers stiltLayers(ObjectPlacementBake bake, PlacementPalette palette) {
         int lowest = Integer.MAX_VALUE;
         int highest = Integer.MIN_VALUE;

core/src/test/java/art/arcane/iris/structure/object/IrisObjectPlacementLifecycleRegressionTest.java

@@ -249,6 +249,15 @@ public class IrisObjectPlacementLifecycleRegressionTest {
         assertTrue(placer.writes().stream().noneMatch(write -> write.y() <= 75));
     }
 
+    @Test
+    public void erodeStiltResolvesItsOwnSampledAnchor() {
+        RecordingPlacer placer = new RecordingPlacer(null);
+        IrisObjectPlacement config = placement();
+        config.setMode(ObjectPlaceMode.ERODE_STILT);
+        assertEquals(ANCHOR_Y, lineObject(1).place(0, -1, 0, placer, config, new RNG(2L), data));
+        assertFalse(placer.writes().isEmpty());
+    }
+
     @Test
     public void explicitMinimumHeightAndFloatingDoNotNeedTerrainSampling() {
         for (ObjectPlaceMode mode : List.of(ObjectPlaceMode.MIN_HEIGHT, ObjectPlaceMode.FAST_MIN_HEIGHT,

core/src/test/java/art/arcane/iris/structure/object/ObjectPlacementGoldenTest.java

@@ -63,7 +63,7 @@ public class ObjectPlacementGoldenTest {
 
     private static final int OBJECTS = 200;
     private static final int SEEDS = 5;
-    private static final long GOLDEN = 0x408f9d4113015897L;
+    private static final long GOLDEN = 0x07dedb3d00b420c0L;
     private static final long MARKER_GOLDEN = 0x60b4bbf1144b239cL;
     private static final long HIGH_VARIANT_GOLDEN = 0xf017622340ecac42L;