Using a portal will not alter the final rendered image in any way, but it makes Octane more efficient in rendering light that comes through the windows. If you render an interior with all light coming from an environment through a few small windows, the image should have less noise after rendering ...

face wrote:Have you try to flip the normal direction?

face

Yes , I've tried the normal Inward/Outward ... still nothing happen . I can attach this .osc file for who interest to try this simple test .... Thanks

I made a very simple scene , with a big window and a plane for simulation of portal light (NORMAL FACING INWARD , no careless mistake I think ... :D )

http://www.mental-production.com/001.jpg

Then I made a couple compared render , 1 of it was plugged w portal material , using PMC :

http://www ...