new reconstruction filter

Hi,

the good ranking my CGSphere image got is a perfect motivation:) I worked a bit further on the VRayIso surfaces. I added a new reconstruction filter. The old version just had a trilinear filter. This is the fastest option, but showed shading discontinuities if you had no Map applied or a map with low frequency noise. I added a BSpline reconstruction filter. I thought this might be a good choice regarding quality and speed. Here's a paper that compares different reconstruction filters. The BSpline filter now generates a much smoother mesh with smooth shading. Of course this costs a lot of speed. Therefore I still recommend the linear filter if you use high frequency noise, because it wouldn't make a difference then. I rendered a small image to show the difference. The cellsize and stepsize settings are the same in both surfaces. Only difference is the reconstruction filter used.
I will do some more tests before I upload it for the betatesters.

My email adress should be visible in my profile now, so if anybody wants to join, just drop me a mail.

Best regards,
Dieter