Luxrender Interior scene with outside plane for background - help please :)

Hi guys!

I’ve been using blender for several years now, and have dipped into Luxrender from time to time. Although I know some bits here and there, I was looking for some info on the following:

I have an Interior render with a bay window (3 windows together). I’ve just got the a sun lamp coming though the windows, plus I’ve used Portals covering the windows and the scene renders reasonably fast. But I was experimenting with adding a background plane of a street scene to help compliment it.

I’m an amature photographer and know that when the interior is exposed correctly then the view of the window exterior (background) will be overexposed - simple stuff. So I created a plane outside of the building and set it as an emitter with a low value so that it was essentially an evenly lit plane (a bit like a shadless material). But obviously to make the plane visible, I had to remove the Portals.

So my scene now takes a lot longer to render :frowning:

Is there a better working method to make the plane visible through the windows and also use Portals, or is this impossible? Will I just have to put up with the extra render time, or is there another method? It would be great if it were possible to have the Portals do their job, but be rendered invisible to the camera.

Cheers in advance :wink:

Update, somone over in the Luxrender forum just pointed it out to me that Portals in lux don’t occlude the geometry, so I can have both Portals and also a background plane behind them - good stuff! :slight_smile: