We need to get a lot of geometry from houdini to v-ray on a linux based system. Any experience on the problem is appreciated.
thx!
Make sure that you are using a newer build of V-Ray; it should support .bgeo files which on the whole convert much faster.
Best regards,
Vlado
That’s great news. But you only done this on Windows?
No of course; you get ply2vrmesh with the Linux installations of V-Ray as well.
Best regards,
Vlado
aaaaaaaahhh! Things are getting clearer, it IS a linux prog allready, Got fooled by the .exe extension.
Cheers mate!
Just for the info, primitive group in Houdini give you the shading group.
Nice. And while we’re close to the subject- how well does vray handle point/primitive/vertex attributes? Can they be accessed by shaders?
What kind of Attributes? Can you give an example?
I guess at the moment we are not skipping unknown attributes.
We are processing positions, normals, uvs and velocities, I think.
/Teodor
Arbitrary attributes. For example, say we have a selfillumination thing going on in our shader we could create a point variable on the mesh that then acts as a multiplier in the shader. Or in my case, I got water that goes from solid to foam, I need to control this by particle attributes that gets picked up by the shader.
You want user attributes in the proxy. I add a thread about this : http://www.chaosgroup.com/forums/vbulletin/showthread.php?65694-User-attributes-in-Proxy (but before in Maya).
I don’t know if it is very diffucult or if this “big” feature can be here quicly.
We start a new feature film with some armies and this feature will help us a lot (for variations in the shader, switch textures, etc etc).
Do it with a color set, and it will work fine - there is a VRayVertexColors texture for accessing color set information from within a shader. Color sets are also stored in .vrmesh files.
For accessing particle attributes, you can use the particleSampler shading node.
Best regards,
Vlado
Not necessarily. For the particular case, Color Sets will work just fine.
Best regards,
Vlado
No, according to your thread your thing would be per object. I want to pickup attributes from points or polygons. In my case these would need to be baked into a houdini geo/bgeo and converted to vrmesh data through ply2vrmesh.
I see; however at the moment ply2vrmesh doesn’t understand those attributes. Even if it did though, eventually they would end up as color sets.
Best regards,
Vlado
Just want to drop some thoughts on this. I’ve recenly discovered that you can’t displace a vr proxy. This is a major drawback as all houdini I/O is happening through proxies and displacement is an everyday thing.
We’ve never really got over the fact that one can’t read/write point attributes either. If you do anything with particles, you want hidden attributes.
My hopes is that alembic will be a saviour for both of these issues and maby your work should be focused on getting that to play with vray but in my experience the I/O currently needs some love to be able to carry through effect heavy productions.
The proxies were not really meant to be a universal way for transporting geometry data between applications; they are just a way to render efficiently a lot of polygons coming from various sources.
I’m hoping that alembic will take care of the geometry exchange thing too.
Best regards,
Vlado
The proxies were not really meant to be a universal way for transporting geometry data between applications; they are just a way to render efficiently a lot of polygons coming from various sources.
I see, thanks for clearing that.
I also think that alembic will be the way to go for exchange…once u have your mesh in maya with additional point attributes you can store the inside vertex colors (if they aren’t already) and use them for shading…those vertex colors can also be stored inside vray proxies…
I’m sure Alembic will take us a long way but I’m still worried about velocity vectors for motion blur and custom attributes for shading. I reckon it will be up to vray to integrate alembic properly rather then getting the data from a maya importer as mayas meshes. It would be interesting to know if such importer might be under consideration?
And to be fair, this should probably be seen as a Maya issue rather then a vray limitation. Would autodesk have opened up their data handling more we would have solved all data shuffling a long time ago. But as that’s not likely to change I guess we have to work around them.
It’s not ruled out and we are trying to figure out if it is worth the effort. Proper support for a geometry format (and managing yet another piece of foreign code) is quite a bit of work, and if we can avoid it and get all the data from Maya, then I’d be happier. If not, then work it is 
But even if we do it, it still won’t be quite the same as .vrmesh files.
Best regards,
Vlado