Hello Folks:

I am trying to use a very basic texture baking setup just to color attributes to a base texture map saved to a png file using bake texture node.

I don't get anything but a white image.

Must be something obvious I'm missing here.

Here is the scene file,

I can't say for certain what's going on (your scene file seems to be missing), but I'm guessing you're looking at the beauty pass instead of the image planes that are extracted. Bake texture ROP by default only outputs opacity in its beauty pass which may appear all white. You can toggle “Disable Lighting/Emission” in the ROP (under Baking tab) to enable full shader evaluation, although the recommended workflow would be to use bake exports and extract the needed planes from the rendered .rat image. Please see the doc [www.sidefx.com] for more info.