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View Full Version : Help with Combustion and Maya Zdepth

Arcon
11-20-2004, 11:04 PM
i'm rendering from mental ray for maya, and i'm testing out the trial version of combustion 3. i'm looking for a compositing app that must be able to do the following 4 things with Zdepth info rendered from maya:

- DOF
- 3D blur
- 3D glow
- 3D fog

can combustion 3 do this...?? IFF files from MRfM contain Zdepth, but i havn't been able to get the effects to work in combustion.... or its quite possible it can be done but i don't know how to use combustion properly yet :)

RLA images rendered from MRfM write out the Zdepth info to a seperate image sequence, and i'm not sure how to get combustion to use a seperate sequence as the Zdepth buffer. another option if C* can't use IFF, is for me to use a depth-shader from maya to get a smooth-edged (fake) Zdepth sequence, but i'm still faced with the same problem of not knowing how to import that as Zdepth in C*.

any help greatly appreciated from people who've used maya with C*.

-paul
Arcon
11-22-2004, 10:26 PM
for those interested, by searching the forum i've found one attempt at solving the DOF effect for maya:

by using a compound blur op and the zdepth sequence as the key, DOF can be generated for an IFF sequence, but it doesn't quite work because although a foreground object will be in focus, the edges of that object are blurred along with the background, which kills the effect and denotes the whole point of DOF. i think this happens because of the way maya anti-aliases the Z channel when objects overlap, which i don't think its supposed to do.... but that's just a guess.

the 3D fog is an easy effect to achieve using a dpethShader from maya and any editing app, but good blur and DOF are a different matter. i've done some more research and a lot of people are saying that with maya's Zdepth, more highend apps like Shake are the only real solution to these problems... hmmm.
Lorecanth
12-10-2004, 03:58 AM
shake is your answer. It can do all of the above very well. and in any case you shouldn't be using straight zdepth data no antialiasing. Just render a 32 bit per channel image with the depth shader. Also if you're looking to stay with windows I believe nuke can do all of the above as well.
pierrejasmin
12-10-2004, 08:09 AM
IFF Z are now correctly extracted in Combustion
Check our RSMB and it's Mental Ray shader friend for your Motion Blur problems at
http://www.revisionfx.com/mblur.htm
http://www.revisionfx.com/generalfaqsMVFrom3D.htm

Pierre
RE:Vision Effects
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