I'm trying to use a RGB ramp VOP as an input to diffuse in principal shader in 16.5 in /mat. Unfortunately, when I plug it in I get a VEX compile error and the shader bugs out:

Errors or warnings encountered during VEX compile:
/mat/ramp1: Shader parameter ramp_the_basis_strings has the same name as a global variable. (17,23:51).

If I just assign the VOP directly as a shader by dragging and dropping, I get the same thing in case anyone else cares to try.

Anyone seen this, reported this or has a workaround?

I only get the error when using the ramp directly as a shader, not when the ramp is connected to basecolor on the principledshader.

-b

I think I had something similar some time ago when I had multiple RGB ramps in a mat network. Not sure but I think for me it was just renaming the ramps to something other than ramp1 or the likes, then it worked, but could have been coincidence of course!

There's something weird with the ramp VOP… indeed as Bonsak says, it works fine if you plug it in, but you can't drag and drop it and use it as a shader itself.

I just ran into the same issue, plugging the ramp into a null node and dragging that node onto the geometry made me able to preview the results of my ramp.