How to use Portals ?

[ingoerik]

I have an interior model that has a 20 meter long exterior wall with three 1 meter wide windows with a distance of 6 meter between each. Should i use three portals, one for each window or is one that covers all three windows enough ? I guess three portals means longer rendertime, or ?

Also i have seen the option to use a mesh for portals, so is it possible to make a polygon for each window opening and add these as a mesh to one portal ? Even if there are more windows from other directions ?

[boyan]

Hey, Eric,

Thank you for the post, if you've already updated to NEXT you don't need to use them, just enable the "Adaptive" option located in GI tab -> below Enable EIS, the option is available in Dome light as well. I think if you replace the portals with area light will be better, also try to increase the exposure value located in VFB.

Cheers,

[ingoerik]

Thanks, but i have not yet updated to NEXT.

[vladimir.nedev]

In my opinion, it's best to use 3 separate portals, instead of one large one.
With the large one, a lot of the shadow rays will end up in the wall, increasing noise and the render time.

Of course, if you can, test it out on your scene to be sure.

As for one mesh light with 3 separate polygons, I am not sure if that would be noticeably better than 3 separate lights, might be.

Greetings,
Vladimir Nedev