Ramps in a Shader

[jim c]

I'm making a SOP DA, and in the SOP there's a SHOP node with a custom shader in it. The shader has 3 ramp parameters. In the SOP's parameter interface I'd like to expose the ramps UIs. I had been going type properties, Parameters, click on the "From Nodes" tab, and then drag the ramps from the material. Is this the correct way to do this?

I ask because it worked at first, then I did some editing on the DA for something else, and all of sudden the material had the yellow-black stripes on it and was warning that all the ramp points were invalid, or something like that? It then wouldn't render right, as if it was ignoring the data on the ramps. Is there a proper way to handle this?

[Macha]

Not sure if it helps but it is known that promoting ramps upwards isn't working very well.

[jim c]

Well, at least I know I'm not alone! I ended up deleting the variables at the Shader VOP level, recreating them, and then adding them again to the DA. At the moment this work. Is this at all related to why you get warnings whenever you use the Simple Ramp shader from the Material Gallery? If I put that in a scene, save it, and then open it again, I get warning about the ramp variables in the shader. They all seem to work OK, but it's really annoying.

[katisss]

Any known solution to this?

[jim c]

No I don't think so. In one of the newer Sidefx tutorials on Vimeo the instructor actually makes a shader with a ramp and runs into this. and comments that this is a known issue and it's not fixed. Really sucks. Makes creating a shader with a number of ramps and turning it into a DA a total PITA.