Planing

Originally, my plan was to simulate the explosion entirely in Houdini, which is a standard workflow for high end FX simulation. However, during production I began experimenting with EmberGen.

Over the past few months I have grown very comfortable working with EmberGen because it allows much faster iteration compared to traditional simulation workflows. This made it easier to quickly test different explosion shapes, densities, and timings while refining the overall look.

Using EmberGen allowed me to focus more on art direction and timing rather than long simulation bake times.

Art Direction

To control the final look of the explosion, several parameters were keyframed over time.

This allowed me to art direct elements such as:

• expansion speed
• smoke density
• turbulence intensity
• dissipation timing

Keyframing these values helped shape the explosion into a more cinematic sequence rather than relying purely on simulation randomness.

Implementation

My initial plan was to recreate the explosion directly inside Unreal Engine 5using real time particle systems. However, due to time constraints and the scale of the explosion, achieving the same visual fidelity in real time would have been difficult.

Instead, I decided to import the volumetric simulation as a VDB (OpenVDB)file.

While VDB files preserve the full volumetric simulation data, they are generally far too large and expensive for real-time rendering in games.

To solve this problem, I used ZibraVDB, which compresses volumetric simulations by approximately 95%while maintaining most of the visual fidelity.

This compression made the explosion usable inside Unreal Engine 5while still preserving the cinematic look of the original simulation.