[HOU-1541] Crash when trying to bake from VrayScene object

[racoonart]

Since baking to another object is supported now (thanks for that!), I tried to bake from a complex .vrscene I exported from max to a simplified object I generated in Houdini. However, as soon as the render process starts, houdini freezes and crashes after a few seconds.
Just to clarify why I want to do that: The vrscene files contain objects with dozens of material assignments and complex shaders (which would be a pain to rebuild in H). I'd like to automatically bake them to simplified objects using houdini.

Vray 4.12.03 daily build: number:6029 hash:21bc157 from 10 Dec 2019 04:38 (the last one I have access to apparently?)
Houdini 17.5.360

You will find a simple scene to reproduce the problem below. Just press render in the Vray renderer in the /Out context

[bdancer]

This is just not supported.

[racoonart]

aaand... won't be, presumably?

[bdancer]

I'll have to check what changes will be required...

[racoonart]

That would be great, I could imagine lots of different things I would push over to Houdini if that worked

[bdancer]

There are a few things that could be confusing:
1. What to do if vrscene contain multiple Node plugins?
2. Now sure yet how to match UV mapping. Scenes from 3dsmax default to 1 as the first channel (and do not use "named" channels), while Maya / Houdini to 0 (and use named channels). Probably I could just extend the bake UI with override index control for 3dsmax case, but user will still have to adjust it manually.

[racoonart]

There are a few things that could be confusing:
1. What to do if vrscene contain multiple Node plugins?

Not quite sure what you mean with that. Some nodes that are not supported when rendering the vrscene file in houdini?

2. Now sure yet how to match UV mapping. Scenes from 3dsmax default to 1 as the first channel (and do not use "named" channels), while Maya / Houdini to 0 (and use named channels). Probably I could just extend the bake UI with override index control for 3dsmax case, but user will still have to adjust it manually.

Manual overrides are perfectly fine for me but wouldn't it be logical to use whatever is the default behavior when loading a vrscene into houdini? I mean, when the vrscene is loaded into houdini, it should render fine, so I would expect it to bake that way too (when I bake in Houdini). But I may miss the point here, sorry if I do . If you're referring to the problem from 1) and vrscene files are treated differently in Houdini and standalone I would go with manual overrides.

[bdancer]

1. Bake works only with Node plugin. Exported *.vrscene may contain multiple Node plugins (e.g. "table", "chair", etc).
2. It'll be manual controls then

[racoonart]

Still not a 100% sure If understand the issue but I would treat the whole vrscene file as 1 object. If there are multiple objects in it I would treat it as one collapsed entity. Not sure if you mean that but if that's not possible I would either throw an error and notify the user about it or let the user pick an object to use (but this would probably be quite tricky to implement and definitely needs a fallback to "the first object in the list" or something like that).

[bdancer]

I've made some tests exactly like "the first object in the list", seem to work, but still under code review.

> If there are multiple objects in it I would treat it as one collapsed entity.

Not sure it'll be possible... vrscene may contain mesh, proxy, hair, another vrscene... but I'll think of some solution...

[racoonart]

Great! Thanks a lot for your efforts, much appreciated