Arnold like volumetric fog
Arnold uses a cheat for volumetric fog that is so powerful it barely impacts your render time. It a cheat because if you make a spotlight with fog and add a colored light source in the fog, the fog will not be affected. But it will take the color of the spotlight and it will cast shadows. In probably 90% of the time you need volume fog, this cheat will do the job. So we could have two modes: physical fog or artistic fog. In this clip, you can see how fast 300 lights are being rendered in CPU on a 2018 iMac. Imagine with a better machine. Currently, the same scene in Cycles takes 4-6 hours instead of seconds.
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Reminds me of "Fast GI approximation" recently added for Cycles - creating GI based on AO to use with Cycles, based on Eevee if I'm remembering correctly. Devs could probably implement something similar here - port Eevee's fog method as a fast option for Cycles. Upvoted.
Not an expert in Arnold, but isn't that effect done by doing something similar to what we can already do on meshes: plugging an emission shader on the volume material output?
If yes, then exposing the volume output on light materials could be a good way to start, we could probably already get nice results just doing that:
Or that:
It's a general env fog setting in Arnold and not a per light solution. Thanks for the tip. We tried. With one light it's ok. Not with 300. :-)
Sure, but I if I am not wrong: what you ask would require to research and write a form of new volumetric shader solution of some sort.
While what I propose - if technically possible, could probably achieve the same end result with less work required from the devs. So it could be done quicker.
But hey, I'm not a dev, maybe I'm talking bananas.
cycles volume is hell slow, a cheat method is far too welcome!
Ayup Blender Bob. This might be a reasonable option whilst you're waiting for the feature to be implemented as arnolds is. I'll also add a new feature to Turbo Render, which will give volume rendering a monumentally massive speed up in cycles.
this is on a gtx 1070 on a 4k monitor, so the rendered area is around 1080p
Thank you for posting this!! An even better example is Nvidia Omniverse’s real-time volumetric rendering. It can render photorealistic real-time smoke and fog. Anyway, fast volumetric reverting in cycles is one of my biggest pain points in Blender.
This is a no brainer for film
I would fake it, add small volume objects around the light (unlike the blend file i would use concial shaped volume objects the next time.
the blend file wich shows the setup can be found here: drive.google.com/file/d/1gE0GuM2PdSd4W17vItdJPmroSJVmTzg5/view
The blend file also includes more than 380 "lights" and more than 350 halo objects (no volumetric shaddows, good for distant lights) and renders in 3 minutes 1080p on a 1070. I defintively would fake it like hell in comp to get better results (bluring etc). Maybe even a halo pass on the volumetric lights.
I know those posts like mine are a bit annoying, but I think maybe something more specific can come out of this. (How to archive that) programming wise sorry for that.
and since I had fun experimenting with it a more "advanced one" to simulate a bit the murky feel of the example video
drive.google.com/file/d/1sCT4gPbrAvcHtKMfFVecE0BBIuWJpc7C/view
This one uses the View distance to fade the density and luminosity over distance to add some "mist" like look. Render time is higher (below 6 minutes) since it doesn't reach the density cutoff that fast. But you could shave of, some minutes by not modifying the density but the color by distance and use a seperate volume pass inthe comp to adjust to it.
Halos in this example do not work that well since the additive nature of them stacking on each other conflicts with the distance fade (needs scne based tweaking)
EDIT: Volume pass only, density fades to 100 % no reflections etc less than 2 minutes
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Thanks for the suggestion Chris. We have point, spots and area lights and we need shadow casting.
ah ok, make sense
This definitely has to be implemented.
Though is this useful without any code or better example?
Perhaps add a link to an article which explains the functionality a bit more
zamn, that will be ingeniously
I would love to see this feature implemented!
We need this
Upvoted.Volumetrics need to be faster! Even if its a cheat.
Wowww that's a game changer. Realtime volumetrics in cycles? Can't wait.. Dev's pls
maybe funding this feature . what can cost the dev.og this feature?
Hilariously stupid post, doesn't explain anything got all the votes from his youtube channel. Wow congratulation let's just add X Y feature in blender and why the stupid devs won't implement the feature, it's so easy just ADD THE FEATURE.
isnt that the entire point of having a "Submit Ideas Features" being open to artists as well as developers? We're artists, not developers, if we we're developers we would have taken a crack at it ourselves.
Hilariously stupid post. Pointlessly ridicules a post for not having a full breakdown of how to technically execute a concept.
You must be confused, so I'll help. The Blender Dev forums are where we share technical solutions to problems and how to execute new ideas. This forum is actually Right Click Select where we throw out ideas and see what sticks and what the users would like to see. It's then the Dev team that decides if there's a feasible way to execute it.
Hope that clears things up for you.
Cool, but how does it work? What's the cheat? What are Blender devs supposed to implement?
They already known the cheat. I spoke with the devs at BCON. Implementing it, that’s another thing. And it’s not on their priority list for the moment.
Ah, OK. That makes sense. It wasn't obvious from your video (or maybe I wasn't paying attention :P )
Hi Bob, Did the Dev's said anything about when they're planing to implement it? Also Eevee needs a realtime GI feature.. that will be awesome.