private void OnEnable()
{
Undo.undoRedoPerformed += OnUndoRedo;
instance = (GRampMaker)target;
instance.Internal_UpdateFalloffTexture();
previewPropertyBlock = new MaterialPropertyBlock();
GCommon.RegisterBeginRender(OnCameraRender);
GCommon.RegisterBeginRenderSRP(OnCameraRenderSRP);
}