Page 1 of 2

Attribute Workflow *FIXED

Posted: Thu Jan 03, 2019 1:10 am
by 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?

Re: Attribute Workflow

Posted: Thu Jan 03, 2019 10:13 am
by 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

Re: Attribute Workflow

Posted: Thu Jan 03, 2019 2:12 pm
by 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.

Re: Attribute Workflow

Posted: Thu Jan 03, 2019 2:30 pm
by 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

Re: Attribute Workflow

Posted: Thu Jan 03, 2019 3:17 pm
by daryl.dunlap
Agreed.

Re: Attribute Workflow

Posted: Fri Jan 04, 2019 12:42 am
by 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.

Re: Attribute Workflow

Posted: Fri Jan 04, 2019 1:47 am
by daryl.dunlap
Houdini has 4 levels of attributes, listed here based on data priority: Point -> Vertex -> Primitive -> Detail.

As described by this image: 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.

Re: Attribute Workflow

Posted: Fri Jan 04, 2019 1:50 am
by abstrax
Got it. If nothing goes wrong, we will change it with the next build.

Re: Attribute Workflow

Posted: Fri Jan 04, 2019 7:08 pm
by blobbybarack
Will be great to be able to use string attribute too with a RGB texture like.

Re: Attribute Workflow

Posted: Sun Jan 06, 2019 2:57 pm
by 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?

Image
Image