Abstract: Traditional firefighting training requires personnel to engage in hands-on practice with real fires, which not only demands significant space and financial resources but also carries the risk of casualties. With the advancement of virtual reality (VR), leveraging its ability to simulate realistic environments for users to complete target tasks has become a key research focus. By utilizing Unity 3D’s powerful 3D rendering capabilities and flexible scripting system, combined with VR’s particle system to simulate flames and fire extinguisher sprays, the training environment for firefighters can be authentically recreated. To enhance simulation realism, the principles of dynamics were employed to model the initial trajectory of the fire extinguisher spray, while a Gaussian diffusion model was proposed to analyze the later-stage dispersion of the spray in the air. Experimental results demonstrate that the principles of dynamics and the Gaussian diffusion model successfully simulates the dynamic changes of the fire extinguisher spray. Additionally, collisions between particles were utilized to achieve the fire-extinguishing process, allowing users to intuitively observe the impact of the spray on the flames.

Key words: Unity 3D, virtual reality, particle system, Gaussian diffusion model, extinguishing