Quote - Paolo can answer the light portal query, assuming siggraph is wrapped up. I've never used them to be honest, but they do have an entry in the RUG.

:)

SIGGRAPH starts on next Monday, the 5th, and I will be driving back home the morning of the 10th. The drive from LA to Santa Cruz is about 8 hours so I will be semi-offline for a few days. Nevertheless you want to keep an eye on the news because I will be making an announcement. I will also be on site for demos and to chat. If anybody is there I will gladly meet with you. 

Anyway, portals are not for focusing or changing the light. They are an optimization tool. With a portal you are telling Lux where the light goes through so that the program doesn't need to waste time working on areas that are not covered by the portal.

Hope this helps.

Paolo

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