hiding a ceiling

[jnoftle123]

im doing a interior scene from a top down view, how would i go about hiding the ceiling from the camera, but having it there for the light to bounce around in?
similar to this view. would anyone have any ideas of how to achieve this in octane
http://www.westcoastillustration.com/im ... 24_big.jpg

Thanks,

[gristle]

This is what you need single sided polygons for. Mentioned it a long time ago, I think the response was there is a slim chance it might be added.

[[gk]]

using the largest possible range for the AO pass you can get very close to the images look refferenced with no ceeling mesh

[jbeau3d]

I haven't tried this in octane but it should work. Make the ceiling specular, 100% white, turn all other settings to 0 and change IOR to 1.0(air), then increase the bounces until it completely disappears. This should give you the desired look; you could also do a seperate AO pass and multiply it in with curves/level tweaks for contrast, as [gk] mentions. I would be more interested in a true ambient pass.

Now if I could get some documentation on the way an *.osc file is structured then I could write a Perl script that would parse a file and swap out all your materials to something specific. This would be ideal for all kinds of custom passes like mattes, object ID's, mat ID, custom AO, etc.

[jbeau3d]

Tested the IOR trick and it doesn't work as expected; due to artifacting. Make the opacity 0% on your ceiling material and that will work.