FadeLODNode not fading

I’ve setup a FadeLODNode and it works a-ok as long as I use fixed-function pipeline or the shader generator but with a shader I wrote.

With a bit of detective work (while writing this post) I found out the the FadeLODNode uses alpha as a ColorScale attribute - ‘attr_colorscale’ in a cg shader, my problem is that I wanted to use GLSL and the attr_colorscale input is not present.

What can I do?

I’ll add a p3d_ColorScale input for the next Panda release.