TerrainData.SetDetailResolution
SetDetailResolution(detailResolution: int, resolutionPerPatch: int): void;
void SetDetailResolution(int detailResolution, int resolutionPerPatch);
def SetDetailResolution(detailResolution as int, resolutionPerPatch as int) as void
Parameters

detailResolution Specifies the number of pixels in the detail resolution map. A larger detailResolution, leads to more accurate detail object painting.
resolutionPerPatch Specifies the size in pixels of each individually rendered detail patch. A larger number reduces draw calls, but might increase triangle count since detail patches are culled on a per batch basis. A recommended value is 16. If you use a very large detail object distance and your grass is very sparse, it makes sense to increase the value.
Description

Set the resolution of the detail map.