Dave Buckley Posted June 25, 2008 Share Posted June 25, 2008 i have a window that needs a sky portal behind it, but its a weird shape. does this matter that i can only do rectangular portals. the window is kind of rectangular but the top edge slants down towards one of the bottom corners. it stops just before becoming a triangle, still keeping it four sided??? Link to comment Share on other sites More sharing options...
SandmanNinja Posted June 25, 2008 Share Posted June 25, 2008 The tutorial I did that came with Max 9 (or was it 2008? Think it was Max 9) had me drag a sky portal the size of the entire house! Don't know if i did the tutorial correctly, but I swear that's what I saw. And did. Sky Portals just 'punch' a hole into the scene and funnel the mrsun and mrsky parameters into that area. I usually bring up light lister, keep the mrsun and mrsky at 1.0 multiplier and then tweak the sky portals' multipliers. If you make the sky portals instances, you can just change 1 and the parameters will change for all (good or bad - u decide). Link to comment Share on other sites More sharing options...
Dave Buckley Posted June 25, 2008 Author Share Posted June 25, 2008 i am ok with controlling sky portals, but the whole "punch a whole in the scene" is what i'm worried about, i don't want it directing light through a solid wall also, i have glass in the windows (a&d thin glass) with sky portals behind the glass. if i take the glass windows out, will the light be different in my scene or will this just affect render time. the glass isn't in shot Link to comment Share on other sites More sharing options...
Dave Buckley Posted June 25, 2008 Author Share Posted June 25, 2008 cool, didn't think so but thanks for confirming Link to comment Share on other sites More sharing options...
SandmanNinja Posted June 25, 2008 Share Posted June 25, 2008 I tend to use poetic license to describe techie things.... We are not worthy.... hehe Link to comment Share on other sites More sharing options...
pfbreton Posted June 25, 2008 Share Posted June 25, 2008 Sky portals are special Area lights that emit energy based on the sky color and intensity. They shoot photons and cast soft shadows exactly like Photometric Area Lights. The right way to use them is to create them behind your windows in such a way that you cast shadows from your window frames. So, yes they can be placed behind an irregularly shaped window. The larger it is, the more samples you need to use as the renderer internally divides the area of the sky portal in small point lights under the hood. Internally, they block FG rays to defer the lighting computation from a "first shot". A usage tips: - make the horizon more blurred in the sky, that will reduce some of the noise inside. - Link to comment Share on other sites More sharing options...
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