Is it possible to make cheap massive volumetric fog with dynamic density?

Hey,

Is it possible to make cheap massive volumetric fog (or anything similar) with real-time dynamic density?

For now the only way I see is to use particles, which is expensive in case of large volumes.

Is there any optimizations/workarounds or, maybe, completely different approaches?

Basically I need to cover up whole field of view for a player (assume it’s a default “Third Person” example) and have a way to control the fog density via blueprints or c++ in real time. Also it should be not a “optional” effect but a significant part of the game, so it should work even on low settings.

UPD: “dynamic density” – I mean I need to be able to change it in real time at any volume’s point (maybe with some discretion), not overall density for whole fog volume.

No no no do NOT use particles for this type of thing. Its the worst idea ever if you ever plan to ship your product, if its just for portfolio shots and framerate dosnt matter then go right ahead.

You should only use Atmospheric fog for theese kinds of effects. Of course you can pair that with a particle system that you might want to attach to the player, but make it super sparse, just to enhance the atmospheric fog effect or have like small ground whisps.

The reason im so strongly against this idea beacuse i haev seen others try to do the same, have a massive particle system cover all of the screen, and it has devistating effects on framerates.

How can I change Atmospheric for density dynamically? I mean, only at specific points, not overall density.

Hello. I know this is an old post but, if anyone reading this and having the same problems… I’ve had the same issue and the way I’ve fixed it was by using the Level Blueprint to check de position of the character and depending on that position, Finterp the density of the fog. Also, you can use volumes and check the collision of it, every tick and check if the character is inside it.
This solution doesn’t make you able to do a visible fog cloud in a certain part of the level, but it is a cheap way to increase the density of the fog in certain parts of the level.

Also. If you want to work more. you can make a system of optimization for different levels of lighting quality, for example, what I mean by this is to make the quality settings a bit more custom by you, for example, In high quality lighting you have volumetric fog and volumetric shadows, in medium you have volumetric fog but no shadows, un low you have default fog without directional light shadows and only ambient occlusion.
(You won’t believe what you can get away with…)