# BeamNG.drive Snippets

## Lua Code Snippets

### Drawing a marker & Vehicle detection

Drawing markers in the map can be one of the best ways to indicate to the user that there is some form of interaction that they can do there.

Drawing a marker is fairly easy. Here is an example of how the bus route marker is drawn:

```Lua
  local function createBusMarker(markerName)
    local marker =  createObject('TSStatic')
    marker:setField('shapeName', 0, "art/shapes/interface/position_marker.dae")
    marker:setPosition(vec3(0, 0, 0))
    marker.scale = vec3(1, 1, 1)
    marker:setField('rotation', 0, '1 0 0 0')
    marker.useInstanceRenderData = true
    marker:setField('instanceColor', 0, '1 1 1 0')
    marker:setField('collisionType', 0, "Collision Mesh")
    marker:setField('decalType', 0, "Collision Mesh")
    marker:setField('playAmbient', 0, "1")
    marker:setField('allowPlayerStep', 0, "1")
    marker:setField('canSave', 0, "0")
    marker:setField('canSaveDynamicFields', 0, "1")
    marker:setField('renderNormals', 0, "0")
    marker:setField('meshCulling', 0, "0")
    marker:setField('originSort', 0, "0")
    marker:setField('forceDetail', 0, "-1")
    marker.canSave = false
    marker:registerObject(markerName)
    scenetree.MissionGroup:addObject(marker)
    return marker
  end

  -- this can then be called in a loop to setup your markers. 
  -- NOTE: You should only do this once as part of your setup and not called on each frame.
  if #markers == 0 then
    for k,v in pairs(nameMarkers) do
      local mk = scenetree.findObject(v)
      if mk == nil then
        log('I', logTag,'Creating marker '..tostring(v))
        mk = createBusMarker(v)
        ScenarioObjectsGroup:addObject(mk.obj)
      end
      table.insert(markers, mk)
    end
  end
```

Here is a custom marker example from [BeamNG-FuelStations](https://github.com/BeamMP/BeamNG-FuelStations/tree/master):

```Lua
  local stations = [
    { "location": [ -778.813,  485.973, 23.46 ], "type":"gas" },
    { "location": [  617.164, -192.107, 53.2  ], "type":"ev"  },
  ]

  local function IsEntityInsideArea(pos1, pos2, radius)
    return pos1:distance(pos2) < radius
  end

  local onUpdate = function (dt)
    for k, spot in pairs(stations) do -- loop through all spots on the current map
      local bottomPos = vec3(spot.location[1], spot.location[2], spot.location[3])
      local topPos = bottomPos + vec3(0,0,2) -- offset vec to get top position (2m tall)

      local spotInRange = false -- is this spot in range? used for color
      local spotCompatible = false -- is this spot compatible?

      if activeVeh then -- we have a car and its ours (if in mp)
        local vehPos = activeVeh:getPosition()

        spotInRange = IsEntityInsideArea(vec3(vehPos.x, vehPos.y,vehPos.z), bottomPos, 1.5)

        spotCompatible = activeFuelType == "any" or spot.type == "any" or activeFuelType == spot.type
      end

      local spotColor = (spotInRange and spotCompatible) and activeColorMap[spot.type] or inactiveColorMap[spot.type] or ColorF(1,1,1,0.5)

      debugDrawer:drawCylinder(bottomPos:toPoint3F(), topPos:toPoint3F(), 1, spotColor) --bottom, top, radius, color
    end
  end
```


## IMGUI Code Snippets

## CEF UI Code Snippets