Opensubdiv border options

[bencowell]

Hello,

I need some help with how the Vray opensubdiv UV border options line up against the Pixar spec and Maya's viewport settings.

I can make a few of them line up against each other but then I'm always left confused by what Maya means by edges and what Vray means by Internal ?

The Pixar specs list :
Linear All - linear interpolation everywhere (boundaries and interior)
Linear Corners only - sharpen (linearly interpolate) corners only
Linear Boundaries - linear interpolation along all boundary edges and corners
Linear None - smooth everywhere the mesh is smooth]
Linear Corners plus1 - CORNERS_ONLY + sharpening of junctions of 3 or more regions
Linear Corners plus2 - CORNERS_PLUS1 + sharpening of darts and concave corners

Maya has:
None
Preserve Edges and Corners
Preserve Edges
Maya Catmull-Clark (I'm guessing this is legacy and not part of OSD)

Vray:
None
Internal
All

[bencowell]

So I've tried all the variations .. see the attached image.

To my eye I'm getting the best results with Maya's Preserve Corners and Edges for viewport preview. This is an ok match with Vray's Internal setting. However they're not quite the same as you can see on that bottom seam there.

Here's how I think they stack up :

Maya None = Vray ??
Maya preserve Corners and Edges = Vray Internal (ish)
Maya preserve edges = Vray Internal (although vray seems to be preserving the very end of the bevel loop which is similar to Maya's Catmull Clark .. see the red ring on the image)
Maya Catmull Clark = All

[ivaylo.ivanov]

V-Ray's method is a separate implementation. It doesn't use the OpenSubdiv's methods (which are different for 2 and 3). Maya also has its own implementation.

[bencowell]

Ah .. thanks for the clarification Ivaylo.

It'd be a very welcome feature in future to support the pixar methods, not that anyone else seems to be .. so far I've found Mari, Arnold and Maya all go their own way.