Laser Beams through volumes

[ptunstall]

Hey,

So I am wondering if it is possible to achieve this effect: http://www.luxrender.net/forum/viewtopi ... =36&t=6485 with Octane.

my current setup has a small plane emitting a TON of light that is at the back end of a long, 0 diffuse, tube. I've attached a few ScreenShots and Renders showing what I currently get but its not returning the results I expect. I am rendering with PMC.

In the screenshot The selected box is a scattering volume. The plane that's tilted near the bottom is a glossy surface with a IOR of 8 with no roughness. The tube at the top is where the light is traveling and the plane on the far right was placed to catch the bouncing light from the mirror plane mentioned earlier...

The render shows a VERY HOT cored beam of light coming down but then after reflecting is HEAVILY diminished.

Any assistance would be amazing!

[profbetis]

If you're looking for a mirror, an Index of 1.0 and full specular should be used. You should also make sure you've enabled "Fake Shadows" setting in your volume, and might also try messing with the kernel's Caustic Blur setting (not sure if this affects volume light though). A lower value should give you a crisper bounce, but take more samples, whereas a higher value will blur more but be cleaner sooner.

[ptunstall]

I changed the index from 8 to 1 like you said and messed with the caustic blur setting, I had already checked on fake shadows. The caustic blur setting does in fact effect the volume but it just blurs it as you would expect and doesn't help resolve the image any better.

[profbetis]

Try roughness up just a little bit, like at 0.001 or 0.01. I think it might help convergence too? but then again it might do the same as caustic blur. Worth a shot.