Is there any information available on how to use the "Light Shader" (karma:light:shader) on light prims? I've had a bit of luck importing the defaultlightsurface hda and saving out a modified version of it and then setting the above parameter to "opdef:/Vop/myshader". However it is very difficult to iterate since it needs to be saved as an hda each time. Is there a way to have it use a live vop shader rather than a saved hda? Is it possible to access custom properties on the light prim?