Tweet
The scene is just a teapot and a plane with one vray light and enviroment GI light. A Mat wrapper is applied to the ground plane to get matte shadows only. I notice in the alpha channel, the matte plane is getting a small amount shadow cast all over it. I am only concerned about the GI and direct light shadows around the teapot itself so this large low level shadow is messing up my alpha. however after trying all variations of include GI, receive GI...etc. it was only when I turned STORE IN IR map in the direct light that the problem went away (see image above). Why is this? Is it because the vray light is large and close to the tea pot?
http://www.geocities.com/highpoly/forum/shadmattes.jpg
The other issue is about getting reflection passes. I know that with matte material in vray, reflects dont show up in alpha (though they do in the VFB) so there are workarounds. I was thinking of just doing all render passes at once except reflections. then put a 100% reflective material (instead of matte one) on the ground plane and then just do a reflect pass. Is this correct?
For some reason, my ground shadows (matte) are showing up in my RGB alpha only and not in Lighting and GI passes. shouldn't they show up there? they dont even show up if i do a shadow pass..does this have something to do with the nature of matte shadow material?
lots of questions here, sorry about that..any help thanks a lot!!
http://www.geocities.com/highpoly/forum/shadmattes.jpg
The other issue is about getting reflection passes. I know that with matte material in vray, reflects dont show up in alpha (though they do in the VFB) so there are workarounds. I was thinking of just doing all render passes at once except reflections. then put a 100% reflective material (instead of matte one) on the ground plane and then just do a reflect pass. Is this correct?
For some reason, my ground shadows (matte) are showing up in my RGB alpha only and not in Lighting and GI passes. shouldn't they show up there? they dont even show up if i do a shadow pass..does this have something to do with the nature of matte shadow material?
lots of questions here, sorry about that..any help thanks a lot!!
