Volumetric Fog feedback thread

Hi ,

Sorry, totally missed this post, dementiurge pointed it out to me on discord…

Any idea if you’ll be able to get this into the next update for 4.18? Nebulas have been smacking me around in the eden project for about six months now, and it looks like vol fog is going to be the only feasible way of solving it at the moment : \

P.S. the solid fog looks , even when it just on the bounding box :slight_smile:

Hi there @DanielW , sorry to be pushy but I need to know what’s happening with the stuff you mentioned in the quote above.

You made that post nearly a year ago, that’s a long time to be silent about a new feature…

In 4.18 a Volume material applied to particle sprites remain the same - the sphere of each sprite is voxelized. But a Volume material applied to any other mesh type causes the entire Object Bounding Box of the component to be voxelized.

The original behavior was incorrect triangle voxelization, which seems to have been working in your case, but in general is quite broken and was not intended as a feature. My apologies for the inconvenience. I really should have just prevented it from rendering completely so no one would have started relying on it, since I knew I was going to change how it worked shortly.

From the docs:

^This was supposed to say ‘Particle Sprites’

Oh well… it’s a shame you can’t leave the original behaviour in as an optional fall back, wrong or not it looks breathtaking on particle beams.

Anyways, you mentioned letting volume materials being allowed to sample the local meshes distance field, which sounds !

Is there any chance that will still happen? Is there any way it could be sooner than later?

Ooh, and most importantly, will this be compatible with procedural meshes?

Cos when I try to put vol mats on my proc meshes atm UE4 crashes : \

Oh, and thanks for making such a revolutionary new technique part of UE4 :slight_smile:

I battled (hopelessly) for most of last year with normal translucency to try and make nice looking nebulas for my galaxy thingy, but now because of all your hard work I can make stuff like the pic below with (relative) ease:

180112_115300_volCylinders.jpg

Am adding a few more screen caps to the eden project thread too if you’re interested…

Hi @DanielW

Sorry to be a nag, do you know if the “volume materials being allowed to sample the local meshes distance field” that you mentioned previously will make it into 4.19?

hi @DanielW ,

bounce :wink:

Hi @DanielW ,

Molatov just shared this twitter link with me from Brucks: https://twitter.com/ShaderBits/status/927966679962877953

https://pbs.twimg.com/media/DODJzsPXcAAtJW8.jpg

Any chance you can find a way to get these dynamic mesh distance fields and volumetric materials talking to each other in one of the 4.19 updates?

sigh .

Any chance of getting this to work with volumetric lightmaps?

Just in case nobody noticed : On Linux, Lights spots | points don’t project volumetric lights. If you make it on Windows and go back on Linux : they disappear.

I noticed that Volumetric fog brightens what’s behind it. This behaviour is unrealistic and disturbs dark environments.

IMO we should be able to create volumetric light without introducing fog.

I agree, there should be possible to add volumetric volumes in places where needed so other places have better performance if volume are not needed. Volumetric volumes could be amazing for artistic control too.

Would it be possible to have “logarithmic” distance quality, so the world would get “compressed non-linearly” into the volume texture?

This would allow high quality fog close to camera while still seeing it in very far away objects.

Why dont you make a BP that has a volume that controls if the volumetric feature on the heightfog is on or off? I mean there are many options on having control over your stuff, just chose one :slight_smile:

Sadly i have not found a blueprint that does volumetric volumes and only closest thing i got is this weird particle sphere but it wont even cast a shadows. I do not know blueprints and only be able to replicate blueprints that had easy short tutorials.

I had to shelve the implementation unfortunately due to other priorities. I am probably tied up for the next 6 months =( Sorry for the bad news. It is very easy to implement it just needs more testing, and I just don’t have the time.

Love the galaxy thing, looks amazing. Wish I had gotten around to Participating media self-shadowing. Whenever you make dense volumetric materials, it looks bad due to lack of self shadowing. It’s a major task though. Like regular shadowmaps but 3d instead of 2d, so very hard to make efficient.

Volumetric Fog is lit by Volumetric Lightmaps, actually that was one of our main motivations for creating a new volumetric lightmap representation, it needs to support GPU interpolation to affect Volumetric Fog efficiently, and previously we were relying on a method which only supported CPU per-object interpolation.

This effect is due to the tonemapper and has nothing to do with Volumetric Fog - you can reproduce the same thing with a translucent sheet. The tonemapper has a non-linear high contrast ‘toe’ which causes this effect. You can reduce the contrast, or use the old tonemapper.

The depth distribution is already exponential and you can control the exponent with r.VolumetricFog.DepthDistributionScale.

Everything here sounds @DanielW !!
I understand the that you guys are currently busy working on other stuff, which I’m also looking forward to for sure.
My biggest question right now, I’ve seen that you understand the problem with selfshadowing, and of course you would like to have it, but It wasn’t clear if this would come to the engine eventually.
I mean, for a feature like this I could wait all the time needed, but it would be nice to know if you guys are planning to add it in the future.
Amazing stuff could be done with volumes with the shape of the distance fields (even more if they are dynamic ones), plus self-shadowing.
I’m really looking forward to those two features coming!
Thanks for your time!