Dave Fothergill

HI,

this is good, and makes sense, however it would be better if all possible attributes in a particle bgeo are added as dynamic attributes to the maya particle shape by the Houdini engine when you press sync. I cant see any reason why you wouldn't want this, as you should only be exporting from Houdini the attributes that you will need.

Thanks,
Dave.

Hi,

on a particle shape, yes all the extra attributes could be stored as dynamic attributes. When using Arnold, the particle shape has a field to type in what attributes you want to export to Arnold. These can then be picked up in shading networks using the aiUserDataColor/Float/Vector shading nodes.

Mesh shapes are different and don't hold point data like Houdini, but can hold multiple colorSets which would be required to hold velocity data for motion blur, and other color data such as opacity or temperature for example.

thanks.

how do I access attributes sored on points in a bgeo?

I read the bgeo cache into the Houdini engine, and can render these particles in Arnold. Standard attributes for color / velocity etc. render fine, but how do I pick up arbitrary point attributes stored in the begeo to use in my Arnold shader. I know what attributes are in the bgeo files, but they don't seem to be available in maya? I put the name into an arnold user data node, but they don't have any effect.