How do I extend a 3Ds Max material correctly

Answer 1

Two possiblities:

1. Does your exporter enumerate all the paramblocks? I imagine that your parameters in the script will end up in an additional pblock. If your exporter just looks at pblock 0 that might be your problem.

2. I haven't seen this usage before where parameters have the same name in the script and the delegate. I think you typically are supposed to make new parameters in the script and assign to the delegate ones appropriately, using different names. At least, that's how I've done it.

Answer 2

Here's a basic extended shader. I think the problem you have is that your rollout is not specified for the parameters. If it's not defined, then you cannot find then, if it cannot find them then exporter get's all buggy.

plugin material Matte name:"Matte" classID:#(0x61108483, 0x4d218a72) extends:Standard replaceUI:true version:1
( 
    parameters main rollout:params
    (
        kdColor type:#color default:[90,90,90] ui:mkdColor
        on kdColor set val do delegate.diffuse_color = val
    )

    rollout params "Matte Parameters"
    (
        -- Basic matte parameters
        group "Basic Parameters" (
            colorpicker mkdColor "Diffuse: " across:2
        )

    )
)