Lighting: glow + reflection problems

# 1 01-04-2005 , 05:06 PM

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Join Date: Mar 2005

Posts: 126

Hiya peeps!

Im trying to make a disco scene where the tile lights change, as spot lights from ceiling move around, as disco ball rotates reflecting lights.

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1) Disco floor = it uses glow attribute for shader, so i dont have to make.. 48 lights underneath.

2) Ceiling lights = they use colored spotlights

3) Disco Ball = phong E w/ reflection + raytracing reflection
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The glow works well, lights up in sequence as i want. Even when a spot light shines on it, it look as i want.

But when 2 spot lights meet each other, the glow becomes crazy bright.

I messed with the glow intensity, and its pretty low on the picture but still it gets crazy bright when 2 or more spot lights hit it.

So i messed with the spot lights. Making it decay makes the shape of light casted into wall to disappear, if i raise intensity.. makes glow go crazy again.

So.. would anyone know a way to not let the spot light affect the glow too much? or when spot lights meet, let it not add up too much light? The floor is blinn, and i tried getting rid of all specularity and reflectivity.

Thanks.

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# 2 04-04-2005 , 11:42 AM

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Location: London, UK

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I would do the glows in comp. If you render the floor tiles on their own as a separate pass you can control all of you glows in 2d. That way you can re-tweak without using maya's awful glows etc.

The reason the go so bright is because maya's lights are additive so 1+1+1= 3 and 3 = super bright glows. Just maya being crap, You could maybe do something with the falloff values to make that stop happening.

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Alan

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Currently working on: Your Highness

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# 3 05-04-2005 , 02:01 PM

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Join Date: Mar 2005

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thanks, i understand the 1+1+1=3 concept on the lights. And exactly what im trying to fix is to get rid of the additions.

and as you mention, it would be the best to tweak in in 2d rather than in Maya.

You mentioned "do the glows in comp", what does that mean? thanks!

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# 4 05-04-2005 , 02:29 PM

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and as you mention, it would be the best to tweak in in 2d rather than in Maya.

You mentioned "do the glows in comp", what does that mean? thanks!

Originally Posted by

Same thing, just render the squares with no glow in maya. but what you need to do is makes ure that you can adjust them in the comp afterwards without affecting the rest of the scene. There are two ways of doing this:

1. Run them as a second pass by themselves and then adjust the glows in comp and place them back over the top of the render

2. run an "ID Pass" which is basically another pass in which the area you want to affect is pure red/green/blue. This allows you to isolate that area in the render and tweak it. So you'd create a lambert material and assign it's colour to pure red and push the ambient value to pure white. This means that there will be no light calcs done on it. Then assign it to all the parts you want to glow and hide everything else or matte them out. Then render that.

In you comp application or photoshop you can then tweak that area easily.

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Alan

Ps. To do a glow in post you make a duplicate the layer blur it and turn the brightness up and the layer it behind the original layer. user added image

Technical Director - Framestore

Currently working on: Your Highness

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Lighting: glow + reflection problems

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