Lighting: Ies Sun And Sky

[Maven]

Here is another shot.

http://www.angelfire.com/hi5/chrisjl/Images/tun2.jpg

[Arnage]

use the lighttracer instead of the radiosity, it works a lot better for scenes like yours.

[Maven]

I need to use the radiosity because we want to measure light levels.

[Aaron Moore]

leonec i dunno how accurate the radiosity will simulate realism. It is based on mathematical principles, and thus will not represent true results...

[Maven]

Its actually pretty close I have a IES Lighting handbook here. and my results are very similar to it. I just can't figure out what is wrong with that surface that causes it to speckle like that.

[zicher]

Geez, I saw that one already, but now I can't remember what the problem was... Not a bug, it was just a setting.

First make sure there are no 2 coincident objects there. Overlapping faces always messes up the z-buffer and produce that kind of effect. But as I said above, it might be the same problem I had a while ago, which was another issue.

Try changing antialiasing method, and other settings in both the rendering and radiosity. I'm sorry I can't remember what it was exactly.

Anyway, your idea of using radiosity for the tunnels is correct. Just make sure you subdivide the tunnels and (but not necessarily) the ground just in front of them.
Decrease the color bleeding to half of the default, or even a third, and use an interactive filtering of at least 2.

[Maven]

Thanks Zicher, I will get those suggestions a try on Monday.

[Maven]

I just thought I would post that I figured out what the problem was.

My model was too far away from 0,0. I draw my models in realworld coords. So I moved it to 0,0 and it is fixed. I guess the further you get from the origin the more mistakes in the mathmatical processing that can take place.

There is allways a solution.

[zicher]

z-buffer issue probably.
It's a bit tricky to set up units and system units in max, but the whole system is there to keep any model within a resonable range for the internal calculations.

I always have that problem whan I use 2 planes to create a ground grid. One plane is the grid (wireframe material) and the other is a matte, just to get some shadows but still see the background.

The matte plane is a bit lower than the grid, but depending on the size of the scene or the angle of the camera, in the distance, the planes start mixing up.

Only solution is to separate them a bit more until the problems goes away. Planes of 100x100 units are never a problem, but when I have 20000x20000 it gets tricky...

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