View Full Version : Switching to Multi Channel OpenEXR

09 September 2011, 05:29 PM
Until now my workflow has involved rendering separate passes from Cinema 4D and VRay then compositing in Nuke. Each pass is brought in with a separate read node and then multiplied and plussed together:

((Lighting/Diffuse) x Diffuse) + reflection + refraction + specular + GI

Cinema 4D R13 has added support for multi channel EXRs and I'm wondering how I should comp these together in Nuke?

Would the 'proper' way be to read in the multi channel EXR, then, for the diffuse x Raw Light for instance:

Attach both A and B inputs from a merge node to the same read node. Then in the merge settings choose Diffuse as the A channel and Raw Light as the B channel? (see attached image)

Or should I use an Expression node? (see attached image)

Do people tend to use the beauty pass and just use the other passes to add or subtract from that?

Any help would be much appreciated.

09 September 2011, 07:27 PM
The most common method (I've seen) is to split out multi-channel EXRs into shuffle nodes and then rebuild the AOVs using Plus, Multiply, etc nodes.

09 September 2011, 08:42 AM
Thanks earlyworm. After watching the Escape Studio's training they suggest either the shuffle method you mention, or the first method I described, connecting both A and B to the same read.

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09 September 2011, 08:42 AM
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