the shape on the left is an import from Lightwave (mesh count 2700), the shape on the right is the render mesh from an object modelled in Rhino (mesh count 3700). if you multiply this by say x10,000 for complex scenes, its easy to see why rhino models will display slower. the objects themselves might not be so heavy, but the render meshes are.
I’m always amazed when I import really complex scenes from Maya/Softimage/Modo/Lightwave etc and they spin around Rhino with ease, no lag in orbit/zoom/rotate at all. But if I was to model the exact same scene in Rhino, it would be clunky and I would have to turn objects and layers off just to make my viewports usable. And there’s no way for me to control it. It’s all handled by the mesher and apart from a few options, there’s not much useful control in there.
So, is render meshing getting looked at for improvements for v6?