cheerfulskeptic
12-13-2005, 11:07 PM
Hello all,
I was wondering if someone could direct me to specific tutorials or give me a brief overview of some good compositing tutorials involving 3D action and live action/CG action... basically to bring two different videos together..
I currently use 3ds Max 7 and After Effects for comping (though I have access to Combustion).
Please correct me if I'm wrong, but here's the theory I know...
1) the lighting in the CG scene has to match the 2nd scene (background, so to speak) - video or cg
2) the camera movements have to match
Thats about all I know!
For example, I have a scene where a bike rider is riding through a canyon. I rendered the bike with Brazil to get a nice photorealistic look. I also have a cg anim of a canyon flythrough (with the same lighting and camera setup as the biker). But I cant get the reflections of the canyon onto the bike!. I cant render them both togther - that would be too much for my machine to handle. Even without reflections, things look strange. I tried using alpha masks, but when i brought them togheter, theres a small outline around the biker showing the cutoff between the biker and the alpha mask.
I guess my questions are:
1) how to fake reflections while compositing
2) how to make a proper alpha mask (i usually render TGA sequences)?
3) If I'm to use 3ds max generated automatic alpha masks, how can i get rid of the thin boundaries that come up during compositing?
Thanks! I hope I explained myself... if not, then please let me know and I'll clarify!
I was wondering if someone could direct me to specific tutorials or give me a brief overview of some good compositing tutorials involving 3D action and live action/CG action... basically to bring two different videos together..
I currently use 3ds Max 7 and After Effects for comping (though I have access to Combustion).
Please correct me if I'm wrong, but here's the theory I know...
1) the lighting in the CG scene has to match the 2nd scene (background, so to speak) - video or cg
2) the camera movements have to match
Thats about all I know!
For example, I have a scene where a bike rider is riding through a canyon. I rendered the bike with Brazil to get a nice photorealistic look. I also have a cg anim of a canyon flythrough (with the same lighting and camera setup as the biker). But I cant get the reflections of the canyon onto the bike!. I cant render them both togther - that would be too much for my machine to handle. Even without reflections, things look strange. I tried using alpha masks, but when i brought them togheter, theres a small outline around the biker showing the cutoff between the biker and the alpha mask.
I guess my questions are:
1) how to fake reflections while compositing
2) how to make a proper alpha mask (i usually render TGA sequences)?
3) If I'm to use 3ds max generated automatic alpha masks, how can i get rid of the thin boundaries that come up during compositing?
Thanks! I hope I explained myself... if not, then please let me know and I'll clarify!