How to multipass render a a scene with complex materials?

[Caveman]

Hi! The scene I am working on has a wall (with two sided material) in front of the camera. The main channel renders fine but all the other channels renders black. Does the mib 2 sided material have any problem with Render Channels.

One more problem I am facing with the Render Channels is that I am not getting the combined result from materials with multiple shaders and textures. For example I have set up a material with some textures on top of an architectural material and instead of getting their merged result I am getting the result from the Architectural material only. I have used the store in color channel, but is their a better way?

Please help

[Hirazi Blue]

I'm unsure, if I understand your question correctly but for using the Architectural Material in conjunction with RenderChannels/Framebuffers (if you are on 64-bits SI) you could/should consider using the Mia_Material_Advanced phenomena by Felix Geremus AKA Mossman (si-community thread).

Mia_Material_Advanced is a shader phenomena which should solve most of your issues with the standard Softimage implementation of the Architectural Material, facilitate working with channels, plus add few additional nice features.

[Caveman]

Hi Hirazi.

When there is nothing in front of the camera, not even the invisible wall, I get the render channels (there's a catch though, I will explain that in the next para). But when the camera tries to shoot through the wall accept for the main channel, I get black renders for all the other channels . The wall has a two sided material with a transparent material on the side which is facing the camera. The main channel renders fine regardless of whether the invisible wall is in front of the camera or not, but the other channels simply won't render when the invisible wall comes in front of the camera. Is there a problem with those two(sided material and render channels)?

My second question is. My render channels doesn't contain the merged final result of a shading network. I got the channels rendered with reflection, diffuse, irradiance etc but no textures were rendered in any of those channels accept the main. How do I get the textures to render in the channels. I have used the store color in channel to render that object in a custom channel, but that would mean I will have to render a separate pass again to add them together.

Please advice I have just started rendering in passes for about a week now and my head is still trying to think like a compositor. Thanks for your patience.

[Caveman]

Hi, I have found the solution to my second question. The solution was store in color channel. This way I rendered both the texture and material in custom channels and merged them together in post without rendering a separate pass. Which is a huge time saver.

Although the first question still bothers me. Why would the channels render black when the camera shoots through a 2 sided material.