camera behind a portal light renders black area?

[wannabeartist]

Hi,

 

I need to render an interior scene where the camera is outside the building - this is so that I can use a more suitable focal length. I use clipping planes to cut out the wall closest to the camera.

 

This works great for regular walls, but I've got one wall with a window that has MR portal light on it: It seems that having the portal light between the interior and the camera causes part of the scene not to render at all (shows as a black rectangle) - funny enough, during FG the image looks fine, but once it starts to render it, part of the image turns completely black.

 

So the problem setup is:

camera >---- portal light --> (clipping plane) ---- geometry

 

If I remove the portal light, the image renders correctly, but of course with totally different lighting - is there anyway to keep the portal light and still get it to render correctly?

[cg_Butler]

Hello.

 

I'm assuming your using an mr Sky Portal Light. In the advanced Parameters roll out there is a tick box called Visible To Renderer. Make sure this is not ticked and also make sure the Transparency: Colour is set to White.

 

If that doesn't help, can post an image of your problem and the light settings?

[Corey Beaulieu]

Try not using the portal and just deleting the glass instead.

[wannabeartist]

Thanks for the tips, guys!

 

It turned out to be the transparency color, which I had set to black and also the portal light was visible to renderer. There was no glass there to get rid of, this was purely misuse of portal light.

 

I did need to adjust the portal light's position a little. I had it just outside a window frame and once I got rid of the black area, I started getting the frame visible in the render, even though it's outside the clipping plane. Pushing the portal light to the inner edge of the frame solved that and I finally got a clean render.

 

Thanks again!

[cg_Butler]

Having it visible to the camera and transparency of black will be why. I think even if it's not visible to camera it will cause a big black area where the light is if the transparency colour is black.

 

Glad i helped you fix it though, I don't even use mental ray! VRay is my renderer of choice. :-)