I work on a scene , where I would like to use the classic volumetric light beam effect.
Using the basic fog shader on the atmosphere doesnt give me the desired effect. As I use quite a few lights to light the scene, adding fog completly washes out the light.
So here’s the question: Does anybody know how to such an effect?
Unfortunately right now there is no way way to create volumetric beams on a per light basis :hmm: But depending on your needs, you can use the good old volumetric light fake, using a cone object that you map with a stretched noise pattern on the opacity channel. Here is a simple scene using that technique - you need the AoN shaders though, because I used the UV/ST feature of the AoN noise to have the noise spread out nicely along the cone. Alternatively you can also use an image map instead of the noise shader, of course. Optional, you can map a cookie image to the spot to create a volumetric pattern on the ground. Hope this helps a bit 
Edit: Here is a variation of that scene that uses an image map instead of the noise shader, in case you don’t have the AoN shaders.
darn… maybe I really have to get these shaders.
Thanks for the project, I never thought of such a simple trick to “fake” that effect!
Here’s 2 simple scenes with a volmetric spot. 1st has an image projected through it, and the 2nd one also has the image, but I’ve changed the noise settings in the atmosphere block. Just make sure ‘scattering samples’ is at 0 before rendering ( under the settings tab / atmosphere block - just noticed it always defaults back to 10, even when loading a project that had it set to 0 when saved ? bug ? )
You don’t need the ‘atmosphere’ material activated for volumetrics to render, just tweak the values in the ‘settings/atmosphere’ block and turn on volume for the lights’ shadow type ( remember turn scattering samples to 0 as you’ll get ‘noise’ over the whole image if you don’t ). Still not as flexible as some other apps but does work, although I’d still follow maks advice and use geometry when possible.
Hey, good finding about the scattering, and the image renders pretty fast with scattering set to 0 Thanks!
Cool examples Maks and MoodyB! 
Yes, the Scattering is full of bugs which I reported multiple times over the years. The Scattering Button doesn’t do anything, so it is always enabled and as you said, setting the samples to 0 is the way to get pretty fast volumetric fog. The Eccentricity value is also not saved and I had other problems with the volumetrics too, sometimes I had hard horizontal lines in my tests. But it seemed rather random.
Other than that, the speed and quality is very good. And scattering of light inside the fog is a fantastic option if you need it.
Also be sure to play with the Random Distribution functions from the dropdown for different forms of volume sampling.
If only they would fix those interface bugs. Should be just minutes to repair that.
I hope that this Atmosphere will be accessible from the shaderflow in future versions, so you can use any noise you want. And that each Light will get a flag for contribution to it.
This would make it fully usable without too much effort.
Cheers!
Thanks for all this help guys!
I’ll first finish texturing and lighting o this one, I realized I have to add the volumetrics at the very end of the process to keep lighting and colorscheme in a balance.
Oh, and well done PMG, the render engine really is fast now, specially when GI (with noise reduction) activated and produces very good results I think.
Coool! Thanks Lyle. :bounce:
Does the fix include all three problems? The Scattering Check-Button not doing anything and both the Scattering value and the Eccentricity value not being saved?
I’m sure you did that already but could the Scattering Check-Button default to off, so that normally people will get fast and clean results. As cool as scattering is, most of the time you don’t want/need it.
How much effort would it be to give each light a “volumetric” flag to determine if it will contribute to the atmosphere (like the shadows already do)? This is the main option missing currently. In scenes with lots of lights, you have a hard time using atmosphere in a defined manner.
Thanks again and best regards
I’ll double check all three…
That’s a good suggestion. Thanx
Yeah, I agree; it’s not ideal. The current atmosphere stuff is a holdover from the old system. It was left in place so that there was at least some option for volumetric lighting until we fully implemented the Atmosphere surface. We have some features in the works, but I don’t want to say much about it until its ready to show. Just hang in there until we can reveal the new stuff:)
Much appreciation for the feedback, Thomas:D
-lyle
Wow, Lyle and Ron poking there heads in this forum is a treat! Don’t be shy, guys … stop by more often.
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