A fume test for a large scale explosion.

I’ve gone for a messy out of control explosion, with lots of secondary explosions after the main starter.

This is achieved with a combination of object and particle sources. As the shape for the object source expands, it dumps out a load of fuel and temp, with a fair amount of object velocity. At the same time a particle source is fired, and also sprays out some fuel and temp (but less than the source). The particle source also emits a fair amount of velocity.

Although the particle source is also burning, some unburnt fuel is left behind above the main fireball. This then catches fire and the fireball expands and rises up. Any unburnt fuel is also caught by the secondary explosions.