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View Full Version : Compositing .rpf and Render Elements (diffuse, specular, etc)

Brian Harp
06-12-2003, 11:42 PM
Hi,
Hope someone can help me to understand this and hopefully I can explain my self what I’m trying to do and hope I'm in the right forum.

I’m trying to learn a real world example of how you would mix the .rpf files and the “Render to Elements” option in 3D Studio Max. Any steps on how to mix these or IF you’re suppose to.

For example, I want to glow specific objects and materials using object and material id’s in the .rpf files In Combustion AND have the control of changing the diffuse, specular, reflection and atmosphere in that scene while having the same control of a .rpf file. Can I do this,...is this the right process everyone else does?

I would like to have the same control of my “Rendered to Elements” option, such as atmosphere, diffuse, specular, z-depth, and so on as I do for the .rpf files. I know with these .rpf files you have incredible control of that image and the information in it. In Combustion I can use these .rpf files to extract a G-Buffer Object ID or Material ID, and along with it, know where these objects are placed in 3D space (Z-Depth).

I’m trying to understand, if I have a diffuse channel and a specular channel (rendered to elements images), how do you extract the .rpf information out of it and how would the layers be set up in Combustion to work with all the same control as an .rpf.

What are the correct steps to take in creating something like this with the most control? For example, how can you use z-depth information in the diffuse or specular channels of an image in Combustion like you normally would with a .rpf file?

Does anyone have any real world examples on how a 3D compositor and 3D animator approach something like this?
I just want total control of all channels (diffuse, specular, reflection, atmosphere, zi-depth etc) and the object id and material ID's (.rpf)

Hope I explained it clearly enough,

Thank You for your help,
Brian
mouj
06-13-2003, 02:30 AM
Could this (http://www.cgarchitect.com/upclose/article9_TB.asp) be helpfull ?

mouj
Brian Harp
06-13-2003, 04:44 PM
Here are more details on what I'm trying to do.

We have a 3D hallway with columns on each side created in Max. Down the middle of the hallway are several electrical arcs and pulses also created in Max. We want to be able to have the POV move from behind the columns while looking at the arcs and pulses, then move into the hallway for a full view of them. Finally, we will composite this footage in combustion and want to have control over the following:

We want to be able to separately control the glows and effects on each of the arcs and pulses. We also want to control qualities of the hallway imagery such as specular, diffuse and atmospheres. And we want to do with as little rendering as possible.

So, here's the issue:

With RPF, we can easily do most of the above by rendering the hallway as an RPF stream, then the arcs and pulses as another RPF stream, then using the Z-buffer and material/object ids to get the effects described above in the composite. The arcs and pulses layers can be composited into the RPF hallway background using the Z-buffer and will be behind the columns at the first of the shot, then in front at the end...just as we want them. And the material/object ids can be used to separately effect the arcs and pulses.

However, with RPF, it seems we don't have control over items such as atmospheres, reflections, specular, etc. that we get with Render Elements...which is vital to the look of the hallway.

So, the basic question is how do you combine the qualities of each of these image types for compositing? Can you use the Z-Depth information in Render Elements to have the matte effect you get from RPF (e.g. - the arcs and pulses behind/in front of the columns)? Or do you have to do a separate matte/shadow pass if you're using the Render Elements approach?

Or can you combine certain Render Elements with the RPF layer of the hallway to control the specular, atmosphere, etc. qualities?

Or are we SOL?

Thanks again for the help,
Brian
Reality3D
06-13-2003, 07:53 PM
Some time ago i was asking that one to my mind 8). And I couldn't get a conclussion. Maybe master of composition can give some tips around this
Reality3D
07-01-2003, 02:30 PM
http://www.cgtalk.com/showthread.php?s=&postid=687768
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