Multipass compositing

I’ve been having trouble reconstructing a multipass rendered scene to look the same as the original rendered image. I need to be able to change the different passes without changing anything else in the image. As it is now I’m not able to reconstruct the combined image from the separate rendered passes and I haven’t even gotten to the color corrections.

If there is a good tutorial or example of compositing the passes back together again i’d like too know about it.

Sorry, the passes are intended to enhance/alter a render, NOT recreate a render. What you are attempting is often questioned on this board with the same answers: A.) it’s a pointless endeavor and, B.) it can’t be done.

Well I’m not trying to recreate a render so don’t misunderstand me, I’m trying to set a good starting point for further adjustments to the render. So I strongly disagree with the statement “it’s a pointless endeavor”, I would even go as far as to say that: “when you take something apart then you should be able to put it back together again”.

My goal is very simple, I want to be able to adjust (color correct, blur, etc…) individual passes without changing anything else. To do this I need to be able to separate the render in individual passes and adjust only the passes I want to adjust and nothing else. At this point simply compositing the individual passes back together again will automatically result in a different looking render, so its impossible to have full control over what you change because basically everything will change.

But of course if it cant be done it cant be done, I hope that this is a point of improvement that would be considered by the Blender developers in the near future.

Hi, MadMesh maybe this can help:

http://blenderunderground.com/2008/03/31/introduction-to-composite-nodes-part-1/

http://blenderunderground.com/2008/04/10/introduction-to-composite-nodes-part-2/

I think this tutorial match exactly your request :cool:

Thank you josecabana, I just had a quick look and it seems to do exactly what I’m looking. I just hope that this compositing technique will translate well to my own scenes. The example scenes are a bit more basic then what I’m trying to do.

MadMesh, nearly any tutorial about something as complex as Blender’s Compositor is going to need massaging to fit specific needs, so unless you can be a lot more specific about what you’re trying to accomplish (maybe post some example stills of your compositing elements?), you’re going to get fairly generic responses. From what I’ve read in this thread so far, it seems that using Render Layers & the Compositor may be a solution (I’ve done discrete color & effects modulations on specific objects in a scene using that technique), but that’s really only a guess because it’s hard to visualize your actual intent.

The examples given by josecabana seem to cover pretty much what I’m trying to do. Unfortunately this is for a commercial project so I cant post the Blend files. Naturally there’s going to be some tweaking to my scene to transfer the technique described in the tutorial but I’m confident it will work. If it doesn’t work or I need more help I’ll be sure to post again.

The examples given by josecabana seem to cover pretty much what I’m trying to do. Unfortunately this is for a commercial project so I cant post the Blend files. Naturally there’s going to be some tweaking to my scene to transfer the technique described in the tutorial but I’m confident it will work. If it doesn’t work or I need more help I’ll be sure to post again.