Comping Reflections

V-Ray V-Ray for 3ds Max General
1

So, I have this scene that has a very large panoramic image as the background. The image is so large that I can’t render the scene with it visible as the image takes up too much memory. So I decided to composite it in. Well, I can’t figure out what settings/blending modes to use.

I’m rendering an animation and am using after effects to comp. Since the frames take forever to render, I’ve done a quick mock-up to test settings. Here’s what I’m trying to do:

This is my reference image. The box represents the background of my actual scene. I rendered the scene with the background hidden (the box). Then I rendered the box with everything else set to matte. Refer to the following images for what’s not working:


I’ve went through all the AE blending modes but cannot get the reflection to look like the reference image. Any ideas? If someone needs these sample files, I can provide. Let me know.

Thanks in advance for any ideas!

2

The blend mode should just be normal. But to get it to work correctly you need to have an alpha channel of the reflection. I haven’t done any reflection passes out of Vray lately so I’m not sure if it saves an alpha with the reflection…But in the past I’ve rendered an additional pass with everything I want to reflect having a 100% white material and making it invisible to camera. This gave me a mask that I could use like an alpha channel.

Tim J

3

use vray frame buffer.
add reflection channel to the g-buffer.
save out seperate reflection channel images.