Light in a room ...

Yoann · Post by **Yoann** » Wed Feb 15, 2006 6:15 pm

Hi !

I had a room maked with 3DsMax, a simple cube, and a light outside my cube. But the light is present in my room... I don't understand why, because all my vertex of my cube are welded...

Somebody can help me ?

Thank you !

Yoann.

Baal Cadar · Post by **Baal Cadar** » Wed Feb 15, 2006 7:06 pm

I don't know what "welded vertices" are, but dynamic lighting ignores occlusion. Back faces aren't lit, but the front faces of the cube lying on the opposite side of the cube are, because they are facing the light.

Only way to fix this is proper light management in your application, meaning to turn off lights outside the room, if you only see the interior of it, or defining the range of the light in a way, that the inside of the cube isn't reached by it.

Yoann · Post by **Yoann** » Wed Feb 15, 2006 9:34 pm

Thank you ...

But It's a very bad new

Yoann · Post by **Yoann** » Thu Feb 16, 2006 10:22 am

Ok... I see...

But what can I desable lights if I'm in my room ... and enable if I'm outside ?

I don't see how to do that ....

Thank you !

Yoann.

Baal Cadar · Post by **Baal Cadar** » Thu Feb 16, 2006 11:43 am

There is no automatic way to do this. Many games use invisible trigger boxes/planes/spheres to trigger some action or change the environment. Invisible means, they only exist in the collision test environment, but not as graphic.
Also a possibility is to turn on/off lights/particleFx/etc by distance checks to the camera. Many different ways to do this, but all ways need a bit of work and additional meta-data.

It is just not enough to through a few meshes, lights and fx in the scene and expect it to be pretty and fast. A huge part of the programming time for a game has to be invested into such micromanagement things. The graphics engine can't help much, because the actual requirements differ greatly from project to project.

Yoann · Post by **Yoann** » Fri Feb 17, 2006 6:34 am

My map is very simple, so, it's not difficult to determinate coordonates when we must enable lights, and when we must desable lights.

Thank you !!!

Yoann

chromdragon · Post by **chromdragon** » Fri Feb 17, 2006 2:18 pm

Have you tried flipping the normal of your cube?

Baal Cadar · Post by **Baal Cadar** » Fri Feb 17, 2006 2:54 pm

With flipped normals a light inside the cube woiuldn't have an effect on the inside of the cube either. Probably not desired either.

Guest · Post by **Guest** » Wed Feb 22, 2006 4:04 pm

I wouldn't triger off the light,, I would put an intensive light into the room with let's say, black or brown color, or set the diffuse parameter of textures down to appear dark beeing enlighted by the light ....and fliped the normals or did an inside roof ..