By Hammer Chen, Kristin Ivanova, Slavina Nikolova
The last blog post “VrayVolumeGrid and Nuclear Explosion” talks about how you can create a nuclear explosion on the ground. But how about a nuclear explosion in a humid sky? In this proof-of-concept setup, I show you how to create nuclear condensation rings with Phoenix, simply by brushing out some smoke from manually arranged Tube geometries. The cloudscape below is also simulated with Phoenix.
How exactly do these condensation rings form? The condensation cloud, also known as a Wilson cloud, is formed by transit water vaporization around the nuclear blast.
“When a nuclear weapon or a large amount of a conventional explosive is detonated in insufficiently humid air, the "negative phase" of the shock wave causes a rarefaction of the air surrounding the explosion, but not contained within it. This rarefaction results in a temporary cooling of that air, which causes a condensation of some of the water vapor contained in it...” Wikipedia
References
I searched for nuclear explosion images on the internet and there are some interesting rings around the nuclear fireball in these photos. Most of the bombs were detonated in the sea, where the humid condition facilitates the formation of condensation clouds.
Overall setup
Let's see how to set the scene. It contains four Fire/Smoke Simulators:
- the nuclear bomb explosion itself that simulates the rings, too (PhoenixFDFire-Nuke),
- the cloudscapes (PhoenixFDFire-Cloud),
- the fog that covers a larger region (PhoenixFDFire-fog),
- and the lower fog (PhoenixFDFire-fog-lower).
Only the PhoenixFDFire-Nuke Simulator and the PhoenixFDFire-Cloud Simulator are actually running the simulation. The other two just have their Volumetric Options tweaked, with no simulation involved.
Let's try to match the real explosion as close as possible. The end result of the simulation fireball is around 520 meters in diameter, which is very close to the size in a reference image.
The nuke explosion serves as a light source in the scene. I don't add any other lights to the environment.
