Create your own ray marcher, or simplify the calculations.
You should be able to heavily customize the released version, which is no doubt still worked on by Ryan and likely includes the very same code.
when working with dynamic lighting the only way I can think of simplifying further is to Not use the volumetric way of doing it, but completely faking it with the use of a static mesh to define the shading.
Obviously this breaks the ability to fly through a cloud and see changes in texture/light, which is not what is happening in RDR2 (only recent game I have seen implementing volumetric clouds, I’m sure there are more, just not privy to them…)
The end result is somewhat similar if not the same. You still get inner shadowed clouds that look convincing at far distances.
While I agree this is not as nice as having the ability to fly through them and having the texture transition like it does with ray marching, the unoptimized performance of the core system is about the same or possibly worse then what is reported above. (Stands to reason since the article is old).
I think, (at this point this is really just a thought)
One could feed a fixed Light Vector to the formula via MPC and re-define the calculations of light passing to essentially fake them within the material.
If you then only change this parameter periodically instead of calculating it every tick, you would likely get a general performance increase.
However, even in this case, the ray is calculated every time the cloud is looked at, making performance degrade based on the size of the volumetric cloud… probably won’t change all that much aside from the general processing improvement of running changes less often.
Anyway, read up on Ryan’s link, and let’s hope he releases some new and improved information now that .25 is live.