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View Full Version : Volume Lights - Help Needed

DracoNB
04-21-2004, 07:07 AM
Ok I'm kind of in a jam and I am hoping that someone can help me figure this out, or tell me that its not possable :)

I have a volume light coming from the back of my scene through a stencil that is transparent. The stencil only allows a little light to shine through, and blocks the rest. However, because it is transparent, I still see the huge ugly original light of the volume light.

The scene is animated, and I want to have the light move behind the stencil so it shines the light through for an effect.

Is there any way to make the volume light not begin until it hits something? Or am I just hoping for to much?

Or is there a way to have the volume light only reflect back onto the front side of the plane, and not allow the plane (because its transparent) to show the rest of the original volume light?

If I'm crazy, let me know ;), and if you have a way to do this, or a work around, PLEASE let me know!:D
Zakkorn
04-21-2004, 09:12 AM
The shadows in volumetric work only with shadow maps. When you put any kind of Raytraced shadows it looks like the volumetric passes through the objects.
JeroenDStout
04-21-2004, 12:17 PM
I see no other way as either postwork, or setting the near attenuation.
DracoNB
04-22-2004, 02:49 AM
Originally posted by Zakkorn
The shadows in volumetric work only with shadow maps. When you put any kind of Raytraced shadows it looks like the volumetric passes through the objects.

Does that mean that it is possable or not? I'm totally confused over all of this :hmm:
Zakkorn
04-22-2004, 08:27 AM
Today I realised something that I forgot to tell you.

1st. To have shadows from objects inside volumetric light you must use shadows maps (as I already told you)
2nd. To have shadows casted from light that passes through opacity maps you must use Adv. Raytracing Shadows or Area Shadows.

But unfortunately you can't have both, yet:shrug:

That means for your problem you must find a different solution just to bypass it.

Try to put a projection map to your volumetric that will much exactly with your stencil.:hmm:

I hope in a future version of MAX solve this stupidity at last.:rolleyes:
cdinic
04-22-2004, 02:26 PM
sounds like u need two lights. Bright shadow mapped light, for the parts that will shine thro, and one dimmer light with no shadow maps to represent the light passing through the semi transparent areas. asuming they are uniform in their transparency. You prolly also want to pull out the near attinuation as mentioned before.

-Chris
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