RayTracing of Lines has wrong colors
The OpenGL, OSPRay and OptiX rendering of line segments differs in a big way. OpenGL correctly does a linear interpolation of colors between the two vertices making one Line Segment. OSPRay does a constant coloring using only the data of the 0-th vertex of the segment. OptiX does worse, in an order that does not seem obvious.
included is a vtkPolyData to test: SevenLines.vtp