problem with environment map and exit portals

[lape]

You need exit portals in both windows. Light only goes through exit portals if one is in the scene.

Now I am totally confused. Exit portals in both windows?

Nothing gets rendered behind an exit portal, right? So if I put exit portals an all visible windows, I can't show what is outside these windows. I had a similar scene with windows on the left, but not visible (with exit portals), and windows in viewing direction, where I wanted to show a terrace outside in front of the room. This won't work with an exit portal.

[juan_irender]

Hi, Lape.
No, exit portal objects aren´t visible for camera...

[lape]

Hi, Lape.
No, exit portal objects aren´t visible for camera...

This the manual:
http://www.indigorenderer.com/documenta ... s-sketchup

And there I read this:
"Finally, note that nothing gets rendered behind an exit portal: when a light ray strikes the portal it is assumed to immediately "exit" or escape to the background / environment, without considering any other objects in the scene"

[juan_irender]

Well, Exit Portal are shortcuts to allow light rays hit the environment/background in a straight way, avoiding more geometry intersection tests.
But environment/background *renders* behind Exit Portals. I left you a pic.

Ciao.

[lape]

Sorry, but I think you missed my aim:

I just want to render an interior room with a view outside the windows, exterior geometry. If I use exit portals on these windows, the environment map is rendered, but the objects that are outside the room can't be seen.

And if I don't use exit portals on these windows, the environment map renders black!

[juan_irender]

If you want that some exterior objects can be seen trough windows, then you cannot use Exit Portals.
After all Exit Portals are rendering optimizers for some situations, so all you will get if you cant use it is... more rendering time.
Updated: I´m not a Sketchup user, so I can´t revise the Sketchup/Indigo exporter options, but I´ll try to replicate your scenario in Cinema 4D.

Ciao.

[bubs]

Lape, I'm afraid the effect you're after isn't completely simple to achieve. Essentially as soon as you insert any exit portal into a scene, then the light will come only from this area. Therefore when you put an exit portal on one window and not on the other the one without an exit portal doesn't allow any light to enter (hence the black window).

At the moment (to my knowledge) the only way to achieve what you're after is a bit of a work-around.

This is what works for me;

1.Create a box outside the window you want to see things through. (make sure the items you wish to see are within the box)
2. Delete the face closest to the camera so that you are looking into an open sided box.
3. assign the 'exit portal' status to all remaining faces of the box. (obviously make sure all your normals are facing the camera.

I've attached a terrible sketch to try and explain myself.
Hope this helps, it should work.

Bubs

[juan_irender]

OK, it seems that your background isn´t emitting enough light. If you want your background can illuminate the scene and also be seen, it must have light emission properties and its emmisive scale must be adjusted properly.
You can have the same texture used for rendering the color (albedo) of the background, used for the light emission section of the material also, or you can use a constant emmisive one (not reccomended for exterior backgrounds).
Here´s a pic: no Exit Portals, so we can see the horizon plane geometry.

[juan_irender]

Nice trick, Bubs!

[Headroom]

Just briefly browsed through this thread, so if this has been said already I apologize.

Exit portals cannot be used selectively. Either all openings to an interior need to be covered, or none.

[OnoSendai]

Just briefly browsed through this thread, so if this has been said already I apologize.

Exit portals cannot be used selectively. Either all openings to an interior need to be covered, or none.

Yes, what Headroom says is correct.

By the way, we plan to add a new type of exit portal that will allow outside geometry to be rendered as well. But for now, nothing outside the exit portal apart from the background will be visible.

[CTZn]

Bubs trick: just make sure that the portals have all edges hard.

I may be wrong here, but a while ago I was under the impression that portals were using shading normals, showing a different result depending on the edges smoothness (kind of bending rays when smooth). If so you want them to have hard edges.

PS: the shape of a portal volume does not have to be a paralleloid.

[lape]

1.Create a box outside the window you want to see things through. (make sure the items you wish to see are within the box)
2. Delete the face closest to the camera so that you are looking into an open sided box.
3. assign the 'exit portal' status to all remaining faces of the box. (obviously make sure all your normals are facing the camera.

Bubs

Ok, seems I missunderstood how to use exit portals the right way. So I have to cover all openings with exit portals. Your workaround is a good idea! Thanks!

[Zom-B]

By the way, we plan to add a new type of exit portal that will allow outside geometry to be rendered as well. But for now, nothing outside the exit portal apart from the background will be visible.

That sound super sweet!!1!

[Pibuz]

Hi Lape!
..I've personally recently had a kind of this "problem" to solve for the last interior visualization I did. Rendering interior and exterior simultaneously was very unefficient, so I ended up putting exit portals on the windows (which is actually the most efficient way I know to render an interior), using the alpha background feature (which actually preserves all the nice reflections on the glasses). Then I rendered a second image, from the same point of view, with only outdoor geometry visible; with the GPU acceleration that took nothing more than a couple hours on an old q6600. In the end, I composited the indoor and outdoor shot in PS, having also the possibility to adjust the brightness of the outdoor region as the client wanted (if you render interio and exterior together, you'll have a 99% probability to get a ultrabright exterior.. but you know that