ParticleQuads

ParticleQuads

A WebGPU particle system where each particle is rendered as a camera-facing billboard quad (rather than a point). The Emitter class updates 50,000 particles on the CPU with vectorised NumPy (position, velocity, colour, life and alive/dead state), and the quads are expanded and orientated towards the camera in the vertex shader. Particles can be drawn as soft circles or squares.

Files

• main.py - scene, camera and render pipeline
• Emitter.py - NumPy particle emitter (birth, update, recycle)
• particle_shader.wgsl - billboard quad vertex / fragment shader
• WebGPUWidget.py - Qt widget hosting the WebGPU surface

Controls

• Left-drag : look around (first person camera)
• Arrow keys : move the camera
• space : toggle animation
• c : toggle circle / square particles
• u : single-step the emitter and print debug info
• Esc : quit

References

• W. T. Reeves, "Particle Systems — A Technique for Modeling a Class of Fuzzy Objects", ACM TOG 1983 — ACM — the original particle-system paper (emission, lifetime, stochastic variation).
• opengl-tutorial — Billboards — expanding a point into a camera-facing quad, done here in the vertex shader.
• WebGPU Fundamentals — Storage Buffers — feeding the per-particle data the quads are pulled from.