on the material you want to have generate the matte, use a rayswitch to make refraction and transparency rays white, all others black (or a different color for each, whatever you need). Then make the other object 100% transparent with a refractive index of 1, and turn off its shadow-casting abilities.
On Thu, Jan 23, 2014 at 11:00 AM, Jeff McFall <jeff.mcf...@sas.com> wrote: > There is a handy booltrace shader by Alan Jones on http://rray.de/xsi/ > > > > That maybe sounds similar to what you are looking for > > > > Jeff > > > > > > *From:* softimage-boun...@listproc.autodesk.com [mailto: > softimage-boun...@listproc.autodesk.com] *On Behalf Of *Eric Lampi > *Sent:* Thursday, January 23, 2014 10:55 AM > *To:* softimage@listproc.autodesk.com > *Subject:* Matte from Geo intersection > > > > Can anyone offer a suggestion how to achieve this? > > Just a simple matte on an object where another one is intersecting, so the > surface inside the volume is white, outside is black. The volume itself > would be hidden. > > The geo isn't very dense, someone here suggested generating a wieghtmap > via ICE, but it won't have enough resolution. > > > > Eric > > Freelance 3D and VFX animator > > http://vimeopro.com/user7979713/3d-work >