IES beams

[panphoto]

Hi, Does anyone have any idea how I can shoot a tightly focused beam of light through a glass object? The image shows my feeble attempt at using an IES light aimed at a glass block. The light disappears altogether inside the block and emerges at greatly reduced intensity. The exit beam shows a little refraction but is very noisy - please can anyone help? Thanks. I'm a Lightwaver but thought it would be quicker to set up in the standalone app.

[UnCommonGrafx]

which render kernel are you using?
(Curious; I have no help for you, sadly. )

[roeland]

Octane won't render a scene like this efficiently since it doesn't use bidirectional tracing. You will need to use the PMC kernel. Reduce the parallelism setting (although you get less samples per pixel, the caustics will converge faster) to the minimum, and the caustic blur setting to 0.

--
Roeland

[gordonrobb]

I was trying the same thing the other day. I added a scatter node also.

I just had a very bright light some distance away from a small opening. This was in Lightwave.

[gordonrobb]

Duplicate post

[voon]

This thread raises a newbie question for me: Can you create lasers?

[panphoto]

Thanks for the replies. I was using path tracing, PMC is much cleaner, but I had to put in a little caustic blur - 0 just cancelled the reflections and refractions altogether. I can't understand why the beam isn't visible inside the glass block though (there's a small gap between the block and the floor). I notice on your prism Gordon that the beam isn't visible inside either. Please could you post your scene files for the prism - you've achieved something I've long wanted to do, the dispersion of a white beam into the spectrum? (Previously, I used the LW Nitisara plugin but had only limited success with it).

[panphoto]

This thread raises a newbie question for me: Can you create lasers?

Yes, Lasers would be very nice!

[gordonrobb]

Thanks for the replies. I was using path tracing, PMC is much cleaner, but I had to put in a little caustic blur - 0 just cancelled the reflections and refractions altogether. I can't understand why the beam isn't visible inside the glass block though (there's a small gap between the block and the floor). I notice on your prism Gordon that the beam isn't visible inside either. Please could you post your scene files for the prism - you've achieved something I've long wanted to do, the dispersion of a white beam into the spectrum? (Previously, I used the LW Nitisara plugin but had only limited success with it).

Away from my PC now, the way I got the spectrum was to add dispersion. I think I have it at 0.04 or something very small.

[panphoto]

Hi Gordon, This shot has .0001 dispersion, but even if I whack it up to .04 there's not much change. I guess that must be down to your scatter node? I figured out that the glass object needs to be on the same level as the floor to get the beam showing up inside. I retrospect I guess that's obvious since the prism is casting a shadow otherwise. David