Light caustics

[Foremancr]

does anyone know how I can produce light caustics that comes streaming through windows. It can also be used for underwater caustics show changing light pattern as the water moves above.

[DjVoyager]

We have a great tutorial that looks at different ways you can use caustics in your scene.
http://www.digitaltutors.com/digital_tutors/video_details.php?v=213
You will have to turn caustics (Mental Ray) on in the lights you're using.

[Foremancr]

The tutorial show photons being added via a light. And the light showing up on a surface with varing effects. What I was looking for was light shining through space not necessary the reflection of light on a surface. In a underwater scene you see light "streaming down through the water" and this light changing as time goes on. This what I am looking for.

[brandeil]

That is volume light, those options are inthe attributes of a spot light, once u turn it on u scale it to your needs.

[Foremancr]

In maya 7.0 they have their on volume light for a selection. I mapped a sequence of frame from a video that I tool of an pool for the caustic. This was inported into the color. I still wasn't able to get the streaming light. I'm still confused. :eek: :eek: :hello

[brandeil]

In maya 7.0 they have their on volume light for a selection. I mapped a sequence of frame from a video that I tool of an pool for the caustic. This was inported into the color. I still wasn't able to get the streaming light. I'm still confused. :eek: :eek: :hello


Is this what u are after ?

[Foremancr]

the volume light works good for the scene with light shinning through windows. The second part of the problem would be caustic lights underwater. I was able to get caustic light to shine as if underwater by piping in some video that used for the water for the spotlight and then select the flog. This wouldn't provide me with the streaming light down through the water. look below

[laxman]

Ok, if you have your frame by frame sequence of caustics that you want to use (and even if you don't just use a 2D fractal) Make a spot light and then click on the light fog button. That will map another object to your light. This object will be a volume object which is chaped like a cone. In the density for the fog, map a 3D fractal. You need 3D because you want to fog to be broken up throughtout the 3D space.

For the caustics you will need another light, in this one map your sequence or a 2D fractal to the colour of the light. You won't need fog on this one.

[Foremancr]

I followed your procedures except I used 1 light for the color using the sequenial frame and moving down the page :jump using the fog map with the 3D fractal. That seems to workout nicely. Thanks for the help

[laxman]

looks really nice, don't forget to turn on depth map shadows and unlink the 'caustic' light from all object in the scene. That way shadows will be created if an object is blocking the ray and you won't get light you may not have wanted.