Attribute Workflow *FIXED Tweet

[daryl.dunlap]

Maybe not a bug, per-se, but, its not intuitive as it currently exists...

In the OBJ params, params are labeled Point Attributes, and only list Point attributes for selection for extraction in the drop-down. However, in the /mat context, the VOP nodes to consume the Point Attributes are labeled as <*> Vertex Attributes.

Is this intentional or some design restriction?

[juanjgon]

Hi Daryl,

Currently, Octane only supports point level attributes (one value for each object point, not for each point of each polygon), although internally in Octane they are called "vertex" attributes, so I suppose that this is why the VOP node has this name.

Thanks,
-Juanjo

[daryl.dunlap]

I do understand that the internal name in the Octane API is 'vertex attributes', but since the implementation is actually 'point attributes' is there any hurdle to labeling the VOP nodes as 'point attributes' in the tool (Houdini)?

Since, if I understand you correctly, you cant actually consume vertex attributes.

[juanjgon]

All the VOP nodes names, parameter names, default values, etc. come from the Octane API to be sure that everything is the same across all the DCCs and the Standalone. I could hardcode the VOP node names in the Houdini plugin, but it is not a good idea at all, because some features, like the LiveDB or the future .orbx proxy referencing could be broken.

In any case, in the future Octane could add proper support for real vertex level attributes, probably retrieved using the same VOP node ... at this point, the VOP node name is going to have more sense

Thanks,
-Juanjo

[daryl.dunlap]

Agreed.

[abstrax]

Please bear with my lack of knowledge about Houdini, but if I understand you correctly, you would prefer to specify different vertex attributes for shared vertices, depending on the polygon that shares the vertex? I.e. similar to UV coordinates and normals?
Just want to confirm, because we can do that fairly easily since on the GPU side we already store the attributes per primitive, but have to change it now to avoid issues with the backwards compatibility of scenes later.

[daryl.dunlap]

Houdini has 4 levels of attributes, listed here based on data priority: Point -> Vertex -> Primitive -> Detail.

As described by this image:

So Yes, Vertex Attributes (similar to UV data) would be very helpful in allowing the Houdini plugin developer to support more levels of attribute data, intuitively.

Thanks guys.

[abstrax]

Got it. If nothing goes wrong, we will change it with the next build.

[blobbybarack]

Will be great to be able to use string attribute too with a RGB texture like.

[aLeXXtoR]

Could you please help me with the primitive color attribute — what setup I must do in Houdini to use that colors with my mesh material?