(Fixed, Fixed) [HOU-2067] [HOU-2074] Material selects crash - Urgent!

[david.anastacio]

Hi,

I'm getting a major issue using material selects, when linking a specific material VFH completly stops/crashes, I tried waiting for a very long time for Houdini to respond again with no luck, everytime I need to crash houdini.
Right now it's happening with a referenced material, but I tested on another clean scene with referenced material and it seemed to work, but in the test scene I attached, whenever I try rendering houdini freezes and this only happens when the "clearcoat" material select is activated. No difference if the material path in the material select is a wildcard or explicit.
I simplified the shaders and removed all textures for the example scene, please check it out.
We are in need of this to be fixed ASAP for a ongoing project.

Also, material selects doesn-t seem to work if you target a reference node which is a real shame.

Best,
David.

[Gosho.Genchev]

Hey david.anastacio ,

could you please send the archive to gosho.genchev@chaosgroup.com
There appears to be an issue with the forum attachments - our ITs are looking into it but since it's urgent for you, I'd rather take a look as soon as possible.

Thank you!

[david.anastacio]

Hi Gosho.Genchev, just sent the attachement by mail. Thanks for looking itno it.

Best,
David.

[david.anastacio]

Forgot to add the additional info:
VFH 4.30.03 from 2020.07.07
Windows 10
Houdini 18.0.397

[david.anastacio]

Also tried with a newer VFH version 2020-07-21 and also does the same.

[bdancer]

We'll fix the crash, however bump brdf can't write to material select channels, you'll have to select smth upper in heirarhy (like add single mtl node), but we may try to workaround it at export time.

> Also, material selects doesn-t seem to work if you target a reference node which is a real shame.

Could u send me a scene for that?

[david.anastacio]

Hi, thanks for looking into this bdancer .

Regarding not being able to export from the bump shader, that's quite bad then, since exporting something after the bump is a no go (since then it's not the shader anymore), and exporting before the bump means then the shader is incomplete.
In general a shader is only complete with bump/normal, and since bump needs to go anter the shader exporting from a bump shader needs to work or a under the hood solution should be implemented.

Here is the issue with the material selects and reference shaders:




This is important for cases were you are instancing a shader through several other shaders and you want to export a material select for only one of those shaders and not all where that instance is used.

Best,
David.

[bdancer]

Well, this is not implemented for BRDFBump at all, so this will take some time and I'll have to check with Core why it's not there...
For V-Ray 5.x this'll be not needed since bump is a part of BRDFVRayMtl now...
And I'll add ref node support, could u send me a simple scene just in case?

[david.anastacio]

Sure,

Attached the example file, or you need the file to be mailed?

Regarding the change you mentioned that is going to happen in V-Ray 5.x, why are you changing it at all? Having the seperate Bump mtl is great actually, will the Bump BRDF will still be there in vray 5.x? Or are you guys removing it?

Best,
David.

[bdancer]

> why are you changing it at all?

Because, umm... Houdini is not the only V-Ray integration we have? And it's convenient for other projects?

> Or are you guys removing it?

Of course, no

[bdancer]

Try today's nightly, that scene seems to work for me.

[david.anastacio]

Thanks for the clarification, so we gonna get more options, that's great then.

First thing tomorrow morning I'll try out the new build, thanks bdancer

[david.anastacio]

Hi again, Just looked into the new V-Ray nightlie and no more crash, thanks bdancer.
Another thing I realized, I assumed that to export the material select of a material with bump, I would need to target the bumpBRDF, and you also suggested "you'll have to select smth upper in heirarhy" , but I now tried targetting the materialBRDF before the bumpBRDF and the material select comes with the bump....doesn't make much sense but I'll take it

Best,
David.

[bdancer]

> doesn't make much sense but I'll take it

Then we need to fix this...

[david.anastacio]

> doesn't make much sense but I'll take it

Then we need to fix this...

Sure, but only fix it when you fixed the bumpBRDF material select export, or I'll lose the bump export

Thanks,
David.