View Full Version : Volumetric Light in mental ray problems

05 May 2009, 10:32 PM
Hey guys, having some issues trying to get volumetric light to work in mental ray.

Right now, I'm just trying to get a single spotlight to send out volumetric light through my very basic scene. Once the lighting is complete, I plan on rendering out only the light rays and fog and compositing them over a separate shot. So, in other words, that little sphere is just a placeholder to aim at. I've been working off of a few tutorials (namely, and and I'm going fairly crazy since nothing seems to be working right. Now might be a good time to check my attachments. The darker image is before I adjusted the cone attribute in my physical light shader, and the brighter one is after adjusting it. The scene file I provided is (if you hit render as soon as it opened) the brighter one.

My problem is such..I believe my scene is set up properly, with a parti_volume on my bounding box, and physical light shader on my spotlight but there is no volume fog whatsoever. All needed connections are made, and I've tried increasing the value of my physical light color and adjusting just about everything I could in regards to photons, but no luck. So now is where I come to the masters.

One last thing, yes I know I can achieve this in software renderer with a mix of just the lightfog node and point particles but the amount of time fussing with that is not feasible at this point when I'm pretty sure I'm just missing something basic in my scene.

Any suggestions?

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05 May 2009, 10:32 PM
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