Combustion RPF and renderpasses workflow

#1

Hey, recently started working with combustion and 3Dsmax coming from Maya and AE.
Ive discovered the RPF files in max and what I can do with them in Combustion, however I have problems combining RPF files and working with renderpasses.
If for example I want to render out a shadowpass for a colorpass I rendered out with RPF, do I have to render the shadowpass with all the RPF information aswell (and add the same operators to it and hope it does exactly the same per pixel as it did on the colorpass), or is there any workaround letting me add layers before adding motionblur for example.
Also is there any other operators besides the ones in 3d post that will make full use of the RPF files, Ive figured out I can do a show gbuffer and choose Zdepth and use that with other DOF operators but besides that?

Any help appreciated.

#2

What you can do is render one pass with the needed rpf data. Render the other passes as another file type like TGA. Create a nested composite with the various passes together. Then use Gbuffer builder on top of the composite. Plug the data into Gbuffer builder from the RPF, this may require the use of the show gbuffer operator to seperate it out. It’s been a while since I used Gbuffer builder so experiment to find out the quickest way to go about it.

Hope this helps some,
-Eric

#3

Back at work, finally got your method working, my problems seems to have started with all the settings that exist in show gbuffer, gbuffer builder and finally the actual operator that does something like motion blur or DOF.
Im having trouble figuring out what good values is for max velocity and more importantly near and far plane on the Zbuffer is. I realized that the scene Im working on is probably extra tricky when it comes to this since I have camera movement which goes from pretty far away from an object to very close, meaning the scale of the scene is somewhat strange, and near far planes goes up to almost 100 000. But is there any way to get a grip on what to use in those fields?

#4

The values really depend on the scene. For the near and far plane these are clamp values, ie anything beyond those values will be black or white. So how far from the camera do you want the DOF to happen? I typically set the Near to 0.0 and adjust as needed in the operator. The max velocity really depends on how fast the object is moving and again is a clamp/scale value. With a higher value you will get more motion blur, but slow moving vectors may not register. With a smaller value fast moving parts will get clamped.

Hope this helps,
-Eric

#5

Am I right when saying, the first, the showgbuffer near/far value is a clamp, while the gbufferbuilder one is a scale? so if I set 0-100 on the show gbuffer one, and then 0-50 on the gbufferbuild one, in DOF I will have 0-50 to work with that represents 0-100 in my scene…?
Anyways, I think im getting it now… one last thing tho, when setting the max velocity, I have to set it fairly high to get nonclamped motionvectors on the closeup shots, which results in very little motionblur/very evenly colored motionvectors in the noncloseup shots. Im guessing Id have to animate the max velocity between the shots to get it to work properly? is this something that combustion does automatically when using 3d post normally (without rebuilding it) for me? Cus from what I can see I dont have any such problems if I just add motion blur to the original RPF layers.

Btw thank you so much :slight_smile:

#6

This thread has been automatically closed as it remained inactive for 12 months. If you wish to continue the discussion, please create a new thread in the appropriate forum.