I suspect that comparatively few 3D programs will render curves (lines and curves being, basically, infinitely thin). The RenderMan 3.2 standard has a RiCurves primitive (I use that for P5 hair in my RenderMan exporter), which is designed to be used especially for hair and fur. The advantage is that you give it a curve and thickness values as input and it'll turn them into geometry only when rendering the respective pixels. Could you take note of the thickness settigns for the hair and export as cylinder/cone segments? (bet that'd make for some large .OBJ files!). Exactly. If you convert hair curves to full-blown polygon tubes, you'll end up wasting a lot of RAM and CPU, compared to the RenderMan way of rendering curves. This poser5 hair rendered Cinema4DXL you might try checking this guys technique(link) although he used several!!! third party plugins to get get p5 splines to render solid you may be able to be able to pull some useful info from it. Yes, I've seen that one. I think this link was posted here a few weeks earlier too. I can't try his method, as the link to one of the plugins doesn't work (site is down). Even if I have to write my own import plugins for C4D or Carrara, there must be an easier way than that.