Storm BasisCurves interpolate varying primvars incorrectly

[spitzak]

Description of Issue

Varying primvars (displayColor at least) are not interpolated correctly. Widths do seem to be interpolated correctly

Steps to Reproduce

Attached rdla file should render six very similar cone shapes using basisCurves, assuming I understand the interpolation correctly. Instead the colors don't match, even though the widths (using the same interpolation as the colors) do seem to match.

System Information (OS, Hardware)

Linux

Package Versions

20.05

curvesVarying.zip

[spitzak]

Above image is with complexity=Very High. Setting complexity=Low will also undesirable artifacts.

[drwave]

RenderMan doesn’t like “linearVarying” and “bezierVarying”: For linearVarying it complains thusly: third_party/renderman-23/plugin/hdPrman/context.cpp -- </linearVarying> primvar 'displayColor' size (3) did not match expected (2) third_party/renderman-23/plugin/hdPrman/context.cpp -- </linearVarying> primvar 'widths' size (3) did not match expected (2) And for “bezierVarying” it says: third_party/renderman-23/plugin/hdPrman/context.cpp -- </bezierVarying> primvar 'displayColor' size (3) did not match expected (5) third_party/renderman-23/plugin/hdPrman/context.cpp -- </bezierVarying> primvar 'widths' size (3) did not match expected (5)

[jtran56]

Filed as internal issue #USD-6319