ray tracing spline surfaces hi net due to further investigation i would like to study the following article peterson ray tracing general b splines proc acm mountain regional conference april unfortunately i didn t find it in any library s register if there is anyone having access to this paper or knowing about a library containing those proceedings preferrably in germany please let me know any help would be appreciated thanks a lot joerg haber joerg haber haberj mathematik tu muenchen de mathematisches institut tu muenchen
