point aligned data colormapping is balky on ospray implicits
By default vtk ospray's point and line representations don't show any colormaps of point aligned values by default. You have to turn off scalar interpolation and go into the nasty mode where colors are interpolated directly instead values (or rather indices into 1D texture map) are.
The reason is that ospray at least initially did not support textures for osp::cylinder and osp::sphere. If it does now we should use it. That will also fix texture maps not working on ospray points and lines.
We might fake it with ospray materials if not, but that isn't a great option.