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API ReferenceGE ExtensionseditortoolUtilities

Editor Tool Utilities – Terrain Painter

Paints terrain materials underneath a spline by rasterising the spline polygon to the terrain grid. Supports revertable operations with stored undo data.

Paints terrain materials underneath a spline by rasterising the spline polygon to the terrain grid. Supports revertable operations with stored undo data.


Public API

FunctionSignatureDescription
M.paint(group)Paints the terrain under the spline using group.paintMaterialIdx and group.paintMargin. Stores undo data in the group
M.revert(group)Reverts terrain materials to pre-paint state using stored undo data
M.revertAll(groups)Reverts all groups' terrain painting

Code Examples

local terrainPainter = require('editor/toolUtilities/terrainPainter')

-- Configure the spline group for painting
myGroup.paintMaterialIdx = 3     -- terrain material index to paint
myGroup.paintMargin = 2.0        -- extra margin beyond spline width (meters)
myGroup.paintedDataX = {}        -- storage for undo X coords
myGroup.paintedDataY = {}        -- storage for undo Y coords
myGroup.paintedDataVals = {}     -- storage for original material indices

-- Paint the terrain under the spline
terrainPainter.paint(myGroup)

-- Revert to original materials
terrainPainter.revert(myGroup)

-- Revert all groups at once (e.g., on tool deactivation)
terrainPainter.revertAll(allGroups)

-- The paint algorithm:
-- 1. Computes AABB of spline division points + paint margin
-- 2. Builds polygon from left/right edge points (binormals * half width)
-- 3. Rasterises polygon using scanline spans
-- 4. For each grid point inside the polygon:
--    - Stores the old material index for undo
--    - Sets the new material index
--    - Marks the point in a set-mask to avoid double-writes
-- 5. Updates terrain grid materials and heightmap
-- 6. Stores all undo data in the group table

See Also

  • Tool Utilities - Fit Polyline - Related reference
  • Editor Tool Utilities – Geometry - Related reference
  • Editor Tool Utilities – Gizmo - Related reference
  • World Editor Guide - Guide

Editor Tool Utilities – Style

Centralised style configuration for spline-editing tools. Provides debug-draw colours, line thicknesses, sphere scales, pulse animation parameters, and ImGui colour theme palettes.

Editor Tool Utilities – Util

Common utility functions shared across spline-editing tools. Provides mouse interaction, raycasting, unit conversions, colour generation, spline helpers, GLTF export, and PNG debug output.

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Public APICode ExamplesSee Also