Material Builder Sub Material Issue

[chadstevens]

Hi there, I'm having an issue where Vray is not rendering the sub-material in a material builder.

For example, I have a single geo node with a sphere and a box and I want them to have their own materials.
If I create a Vray Material Builder and create a material for the box and the sphere and assign it to a material node in sops, it only uses one of the materials. I think this is a BUG.

The way I've gotten around this till now is to use a PatternID node and the name attribute to apply to sub-objects in SOPs

The main problem is when I take it to Solaris this doesn't work, but strangely enough the first method does.

So I can't get consistent results.

For Non-Solaris (SOPS): I have to use PatternID
For Solaris I have to assign the sub-material in the material builder to the components individually.

I would like both these methods to work if possible.
Let me know if I'm doing something wrong.

Here are some screenshots to illustrate my problem.
I've also included a Hip File.

Houdini 19.5.605
V-Ray for Houdini number:22528 hash:aa5d38d from 03 Oct 2023 00:57
V-Ray Core 6.10.20 [b1a7ffe9] from 2 Oct 2023

[bdancer]

What V-Ray for Houdini version are you using?
Both work for me without any issues...

[chadstevens]

bdancer thanks for getting back to me, It's in my original post.

V-Ray for Houdini number:22528 hash:aa5d38d from 03 Oct 2023 00:57
V-Ray Core 6.10.20 [b1a7ffe9] from 2 Oct 2023

Cheers.

[chadstevens]

bdancer I've just tried this on the latest nightly and I'm still having this problem.

Build: V-Ray for Houdini number:22651 hash:82c1b12 from 18 Feb 2024 02:06
V-Ray Core 6.20.05 [31923cf8] from 17 Feb 2024

[bdancer]

I'm on the latest nighlty as well, so I'm not sure how to help you...
Attaching Solaris and non-Solaris result:

[chadstevens]

bdancer Alright, I'm not sure what to do either. Are you using Houdini 20?

I might need to uninstall all my Houdini and Vray versions.

[bdancer]

Yes, I'm on H20, but this particular code is there for years...
You could drop me a line to the email in my signature for a TeamViewer session if you have time.

[chadstevens]

bdancer thanks very much for the help, I'll try uninstalling all the versions of Houdini and Vray I can to see if that fixes it, if not I'll, try and get you on TeamView if you're available.

Cheers.

[chadstevens]

bdancer Okay, so I uninstalled everything and reinstalled Houdini 19.5.805 and the latest Vray Nightliy and I'm still getting the problem but I've been testing it with the IPR and that's where the problem lies, if I try to do a production render it works. see attached

Is this a bug?

[bdancer]

> Is this a bug?

Yes, for sure it must work in both IPR/Production...

[chadstevens]

bdancer Alright, thanks for getting back to me. So is this happening on your side as well or is something on my system that's causing an issue?

Cheers.

[bdancer]

> So is this happening on your side as well or is something on my system that's causing an issue?

Ok, this particular setup has a kind of bug, but in general it's not entirely correct... For some reason you've:
1. removed output node from the builder (is there a reason for that? this node is important)
2. using different shaders from the same builder (which is considered single material) as separate materials
If you separate your setup in 2 different material builders everything will work.

[chadstevens]

bdancer Yes, I removed the output node because Solaris doesn't see the output node as a material, this was my original problem.

I create many variations of materials in a single material builder as I can reference different parameters more easily, I do usually use an output node, but when I created a complex material that used a pattern ID to apply to different sub-objects it didn't pick it up in Solaris and didn't work at all, which was the reason I created this post to find out the correct way to make materials that work in both SOPS and Solaris.

Let me know if you need any more information.

Cheers.

[chadstevens]

This is the Setup I've been using in SOPS but it doesn't work in Solaris.

So if you IPR render this in SOPS it works great, but if you go to stage and enable viewport rendering it doesn't work at all.

[bdancer]

> I removed the output node because Solaris doesn't see the output node as a material, this was my original problem.

You don't need to select output node, select material builder itself.

The problem here is that you expect some things to work in USD the same way as in SOP, which is not correct in all the cases.

TexPatternID works in Solaris the same way as in SOP, however no-one guarantees SOP names will be translated the same into the USD.
What is the object paths in the stage? the same as in obj heirarhy?
Are you using custom string attribute or rely on scene path?

> I create many variations of materials in a single material builder as I can reference different parameters more easily

I'm not sure we'll invest time in fixing various issues (as this one) relates to this because it's not the intended workflow...