DirectX Compute is incorrect.

[RogersDoug]

Load in this large model into dxViewer: https://www.dropbox.com/s/fv5kfmveepkosb4/825_napoli.obj?dl=0

Under 'Compute', Select HLSL Compute

[manuelk]

I have noticed some "interesting" issues there recently as well - i'll try to take a look, but it will take me a few days to get to it.

[RogersDoug]

Any update on this?

[davidgyu]

Thank you for reporting this. Yes, it looks like there may be bugs with the DirectX viewer and DirectX compute evaluator when evaluating very large meshes. One is that Osd::D3D11ComputeEvaluator::EvalStencils() isn't always evaluating all of the stencils. We'll dig into that!

One thing to note is that this test case is almost a worst case for Catmull-Clark subdivision. If you start with the exact same data points, but connect them using a quad mesh topology instead of a triangle mesh topology, then this test case will run fine.

Otherwise, at the first level of subdivision, every triangle is being subdivided into three quads each of which is extraordinary. This results in a huge increase in the amount of data and computation needed to process the mesh.

[jtran56]

Filed as internal issue #151671.