MaterialXLoader: Implement separate(2|3|4) nodes

[aardgoose]

Fixed #29426

Implement separate(2|3|4) nodes, this is the first multi output node as far as I know so possibly incorrect.
Appears to work with provided test sample.

@beersandrew can you test?

[beersandrew]

Related issue: #29426

Implement separate(2|3|4) nodes, this is the first multi output node as far as I know so possibly incorrect. Appears to work with provided test sample.

@beersandrew can you test?

Hey, thanks for the quick response on this one, really appreciated!

I'm seeing some issues, I've added separate3.mtlx & separate4.mtlx samples in my MaterialX fork and I expect to see the following.

2,3,4 from left to right.

but I currently see this on the current branch:

not sure if this is helpful but it seems that when I step down into the nodes produced underneath the colorNode each SplitNode instance has components of x.

Let me know if you're able to reproduce this with

const SAMPLE_PATH = 'https://raw.githubusercontent.com/beersandrew/MaterialX/separateNodeExample/resources/Materials/Examples/StandardSurface/';

const samples = [
  'separate2.mtlx',
  'separate3.mtlx',
  'separate4.mtlx'
];

[aardgoose]

@beersandrew
I think I have fixed those cases, the initial input was being cached so that the outx was used repeatedly, and output elements weren't handled. Both those fixed now.

[beersandrew]

@aardgoose looks good to me as well, thank you so much!