Sky Portal

[glorybound]

When using a VRAY light, in a window as a portal, is the light inside or out? Or, does it matter?

[Pixelcon]

out.

http://www.youtube.com/watch?v=fJm8eZaEWYQ&feature=plcp

This video wont play for me at the moment but I believe there is a demo on how to properly set them up at some point during the video.

[snivlem]

Just wondering, now that the question has been resolved (sorry if this is a hijack) but does everyone here just put portals on a few main large windows? Or does everyone put portals on every single window in a scene?

[Svetlozar Draganov]

Just wondering, now that the question has been resolved (sorry if this is a hijack) but does everyone here just put portals on a few main large windows? Or does everyone put portals on every single window in a scene?

There is no general rule about that. If you are happy with the illumination by using portal lights only on main-large windows you can leave the small ones without a portal-light - this will save you some render-time and optimizing-time. But if you need more light into your scene - you have to use every chance - and in this situation small windows can help you a lot.

[Svetlozar Draganov]

When using a VRAY light, in a window as a portal, is the light inside or out? Or, does it matter?

There is a sensitive difference between inside and outside portal-lights.

Outside portal lights (where the portal-light is behind the window) - produce more physically correct end-result but it is noisier and darker than inside-portal-light, cause the light pass through window and eventually other blocking geometry as blinds curtains and etc.

Inside Portal Lights (the light is in front of the window) - produce more illuminated scene and less amount of noise - the render-times will be lower because Vray will need less samples. The downside is that the result at some situations is somehow unnatural.

In general I always start with outside portal-lights , and If I am not satisfied with the illumination I move to inside portal lights.
In some situation the combination of both could be the best choose.