| paintContext | PaintContext describing the area we are editing, and the terrain space. |
| brushXform | BrushTransform from terrain space to Brush UVs. |
| material | Material to populate with transform properties. |
Sets up all of the material properties used by functions in TerrainTool.cginc.
TerrainTool.cginc contains useful transforms for terrain tool shader; this function fills out the material properties necessary for those transforms to work properly.