.:: Indigo 0.9T5 and Exit Portal -- second part

General questions about Indigo, the scene format, rendering etc...
alex22
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Location: Germany

Post by alex22 » Fri Aug 17, 2007 12:38 am

Exit Portals look like a non transparent zero alpha material in Blender. They make a portal from the infinte sky into the room. Through this portal light gets into the scene. You could imagine it as a camera, which takes a picture of the incoming light, with its direction from where it comes from. Then it emits that picture in the exit portal.
Thats what I think.

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Kram1032
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Location: Austria near Vienna

Post by Kram1032 » Fri Aug 17, 2007 12:48 am

ONLY non-geometry lights go through an exit portal.
That means:
1) atmosphere (old)
2) background light (although, no one tried that, I think)

How they work, I already answered, hundreds of times, although, that's how I explain it myself:

not a single ray hits any surface, "outside" the portal. Only the atmosphere, which actually is a lightsource.

If there's no light, the portal looks black. (In case of BiDir, at least)

Also, incase of the normals pointing in the wrong direction, you get wrong pics. Check them. (Normals need to point in the direction, the light flows)

_Inside_ a room, is, where the normal of the exit portal points, to :)
_Outside_ is, where the normal points away from.

Btw, I've no idea, what happens, if you use a plane, with thickness, with all the normals pointing outward.

They let light trough? I didn't know that...
Light is forced to go through the exit portal, but the portal doesn't check for geometry behind it.

mrCarnivore
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Location: Stuttgart, Germany

Post by mrCarnivore » Fri Aug 17, 2007 1:14 am

I don't think you understand me...

I know how to use exitportals for "normal" conditions and that the hdr and sky are visible through it and that you have to cover all openings for unbiased results and such!

What I don't know is, whether meshlights are actually uninfluenced by the exitportal and if to meshlights the exitportal is just a non-transparent geometry...

Also I would like to get confirmed, if it's true that if at least one exitportal is in a scene, the sunlight/hdr HAS to go through an exitportal before the rays become visible.

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Kram1032
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Location: Austria near Vienna

Post by Kram1032 » Fri Aug 17, 2007 1:27 am

An exitportal erases the geometry. And I *think* meshlight can't pass, either.

When there is an exitportal, light comes visible, as soon as it passes the Portal, if you set BiDir to true.
In non-bidir scenes, light passes anyway, for some reason.

But as Ono already said: Don't use exitporals in anormal conditions

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