Archviz background through glass vs open window

[flipside]

Hi,

I've seen this problem come up a lot, but never really saw a real solution.

If you use color mapping, with affect background turned off, you have problems with the background image if you have both regions with and without glass windows.

See this pic:



Left is glass window, and the bg is affected by the color mapping because actually it's the refraction that gets color mapped. The right side has no glass, you see directly the image, so no color mapping is applied here. Because of this there is a huge difference between left and right.

All you archviz guys must have had this problem a thousand times. What are the possible workarounds?

Thanks in advance,

flipside

[egz]

I'd render once without BG image, but with alpha channels through the glass. Then render a separate BG pass and comp it all in PS, AFX Combustion or whatever you prefer.

[doan]

Since there is a tranparency problem beetwen glass surface and background, the only solution which works is the one explained by Egz.

- Anoyher way also, when you use Coreldraw as the post process program, is to add your background there. That works fine for me...

[kippu]

ok i am having the same problem and i just could not solve it without a standard material for the glass..... egz or anyone else .....can you please teach me how to render the pass with alpha channels through the glass ....its kinda bothering my head now

ok i chatted with egz on msn and he helped me out ......just a simple affect alpha check box