public static PaintContext BeginPaintSurfaceMask(Terrain terrain, Rect boundsInTerrainSpace, int extraBorderPixels = 0) { int surfaceMaskResolution = terrain.terrainData.surfaceMaskResolution; PaintContext ctx = InitializePaintContext(terrain, surfaceMaskResolution, surfaceMaskResolution, Terrain.surfaceMaskRenderTextureFormat, boundsInTerrainSpace, extraBorderPixels); ctx.GatherSurfaceMask(); return(ctx); }