Volumetric light in animation

[Paul Davison]

Hello, I was wondering if anybody could give some advice on how to animate in 3ds Max, using Vray (mainly sun and sky system) and get nice volumetric lighting. I can only get it to work with standard lights and and loathed to put them in the scene which will give additional illumination. Is there a clever way to get a 'light mask' using the render elements to then use in After Effects?

 

Thankyou in advance for any help

 

Paul

[CJI]

If you do a quick search there is quite a few threads regarding this topic already and the different ways it can be achieved. I'll start you off and link you to one

 

http://forums.cgarchitect.com/39855-god-rays-vray.html.

 

There are others though. Happy Hunting, let us know how you get on and how you decide to do it.

[Paul Davison]

thankyou, i'll have a good look!

 

Paul

[Paul Davison]

one thing that occured to me was duplicating the scene, replacing the Vray light/sun with the standard light to create the Volumetric effect, then replacing all materials in the scene with a matt black then render the animation. What you are left with is an animation/still that can be placed on top of the fully rendered scene giving the layer a 'screen' layer type in post, then you should have the effect but with full control how strong you want it

[CJI]

Thats the way i have done it before as what your are getting is essentially a

volume light pass and a mask at the same time. It works very well if your happy managing a seperate file. What you could maybe do is set up a seperate scene state to handle the conversion rather saving a seperate file? either way is fine though. If your happy with the post work your render time becomes a fraction of what it would be to handle it all in render while alos giving you control.

 

I don't know how Vray handles the max standard volumetric effect and lights but i know that mental ray has a hard time with it in that you really have to up the sampling to get the quality you are looking for. Either way you can always switch to scanline to get the pass.

 

Looking forward to seeing your results.

[Paul Davison]

that's what I was thinking, scanline all the way, nice and speedy renders! I'll upload some screen grabs when it's finished

 

Cheers!

[erickdt]

Just use a standard light with everything excluded from it's illumination. Then set up the volumetric light as you normally would with. Works like a charm every time :-)

 

E

[CJI]

But if you exclude it from all the objects how will the volume light cast shadows, say through and open window?

 

For general atmosphere fog though thats a great tip actually. I never thought of that.

[Chad Warner]

I just went through all this with an animation, and the way I ended up doing it was exactly as suggested, with a separate scene and standard lights with volume light. In order to get the right effect with the building, I just made it so all the geometry was not visible to the camera, but still received and cast shadows and atmospherics. In my case, it was all exterior, so I wasn't concerned about coming through an open window.

[erickdt]

But if you exclude it from all the objects how will the volume light cast shadows, say through and open window?

 

For general atmosphere fog though thats a great tip actually. I never thought of that.

 

 

You just exclude everything from illumination, not shadow casting. Another way you could do it is by having a map in your light with the volume light effect that simulates your window mullions.

 

E

[CJI]

Im with you. I thought you meant exclude it from the light but that wouldn't make sense. If i had thought about it for two seconds i would have seen it but i was being slow. Apologies.