Jump to content
Szymon

Volume Light and some FX

Recommended Posts

Hi,

Can some of you provide short tutorial how to create volumentric light and a lenzFx?

I remember that Jason said on mailing list:

"use the VEX Lit Fog atmosphere shader for true raymarched volumetric lighting"

and Justin said

"Actually this a little different from 4.# because you used to be able to use a light obj. in the atmosphere parameter in the shading page, set up fog settings then just make sure your light was visible when rendering, but unless you use Omantra it wont render.

Also the same with a lens flare you would just add a atmosphere obj. set it to lens flare and adjust as needed, but mantra (or Vmantra) doesnt render lens flares, at least it didnt used to.

you can how ever use a atmosphere obj. with a shop fog shader but Im not sure if the light interacts with the fog."

Can somone explain what I'm doing wrong? Why it can't be rendered with Mantra? I create a light then in shading tab choose Atmosphere making some LightBeam but it's not rendering with Mantra. Why I have to use Mantra3 to render that?

Can someone provide a demo .hip file explaining this?

Cheers,

Szymon

Share this post


Link to post
Share on other sites

I had the same problem a while back.

I was trying to have volume light coming through a hole in a cave to illuminate my little monster, but couldn't get lbeams to work with mantra.

It worked with omantra but the whole image was swarmed with volume instead of just the lights' radius which I did not know how to fix.

Share this post


Link to post
Share on other sites

If you have BMRT, or any other RenderMan renderer, at your disposal you should try that for volumetric lighting. (Since BMRT has a few volumetric light-shaders included. Also PRMan I believe).

Share this post


Link to post
Share on other sites

Sory about that - enabled Attachments now..

So, Szymon - did you get sorted out? Questions answered? Or are you still having trouble?

J.

Share this post


Link to post
Share on other sites

Not really. Only a little bit :blink:

Compiled AndrewVK's shader and it works ok, but can't find everything I want. Can't get cone spot for example...

Isn't there any posibility to get it in any "standard" way? Why it can't be rendered via Mantra but only via M3?

Share this post


Link to post
Share on other sites

Speaking of this issue... Wouldn't it be possible to build something similair to the BMRT "rayserver" concept? With that program you could render hybrid scanline (PRMan REYES) / raytracing & radiosity (BMRT).

So well, would it be possible to render like that in Houdini. Say, you build a TK/CMD script that renders with mantra and switches to mantra3 for the volumentrics?

Share this post


Link to post
Share on other sites

So, come on folks, what do you suggest? Render everything I have in Mantra, all atmosphere lights in Mantra 3 and composite? Isn't there any solution to build some VOP which will help with that problem? Maybe some of you guys will explain how do you agree with volume atmosphere light effects, how do you create it, etc.? It's quite weird and I can't find the clue :blink: Am I sentenced for Mantra 3?

Share this post


Link to post
Share on other sites
So, come on folks, what do you suggest? Render everything I have in Mantra, all atmosphere lights in Mantra 3 and composite? Isn't there any solution to build some VOP which will help with that problem? Maybe some of you guys will explain how do you agree with volume atmosphere light effects, how do you create it, etc.? It's quite weird and I can't find the clue :blink: Am I sentenced for Mantra 3?

Rendering the different elements and then compositing them by hand doesn't sound bad at all, though I think it could be a little tricky with volumetric lighting. But if it would work out, it would save you a lot of time by not having to build custom shaders (VOPs) or on like a possible "rayserver"-ish concept that I suggested in one of my earlier posts in this thread! :)

Share this post


Link to post
Share on other sites

An easy way to get same as with mantra3:

1. make i3d texture ( simple sphere )

2. Place a normal light(fastshadow) with a projectormap (some black and white noise ) on top of the athmosphere object, wich includes the above 3d-texture and

than render the scene.

you get some very nice lighstreaks :rolleyes:

Share this post


Link to post
Share on other sites

Cheers Mike, knew that already. I thought about the same but in mantra (not 3). Didn't solve it and don't know if it's possible :(

By the way: can I use i3d with volumentric light in mantra3? Cos, as far as I tried, I can render i3d cloud only in mantra and atmospheric light in mantra3? Am I wrong? :blink: Couldn't do both together :unsure:

Share this post


Link to post
Share on other sites

No, you cannot use both together.

But I thought that's the solution what you are looking for <_<

mantra3 --> volumelight with projectormap

mantra --> i3d + light + projectormap

you get close the same result !!

where is the problem ??

Share this post


Link to post
Share on other sites

Wanted to get sky with volumentric streaks going throught clouds. Fast 3dsmax example (just for idea) below. This sh.t ball shold be a cloud.

post-15-1032342136.jpg

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×