particles-gpu_skill

Overview

This skill implements GPU-based particle systems using instanced rendering, buffer attributes, Points geometry, and custom shaders to render thousands to millions of particles efficiently. It provides patterns for positioning, per-particle attributes (color, size, velocity), and both CPU- and GPU-driven animation approaches. The goal is high-performance visual effects like snow, rain, starfields, and abstract generative visuals.

How this skill works

Particles are represented as BufferGeometry attributes and rendered with Points, InstancedMesh, or custom ShaderMaterial depending on needs. Per-particle data (position, color, size, velocity, alpha, etc.) is uploaded as Float32Array buffer attributes and can be animated either on the CPU by updating buffers or on the GPU via vertex/fragment shaders. The shader approach uses uniforms (time, pixel ratio) and varying values to control appearance, size attenuation, soft edges, and movement entirely on the GPU for maximum scale.

When to use it

• Rendering tens of thousands to millions of tiny particles where CPU updates become a bottleneck
• Creating glowing or additive effects (stars, fireflies, snow, rain) that need efficient blending
• When you need per-particle customization (color, size, alpha) without many draw calls
• Using instanced 3D geometry for small counts that require real shapes instead of sprites
• When precise animation, wrapping, or procedural motion is best handled in GLSL for performance

Best practices

• Prefer Points with custom shaders for 100k+ particles; use InstancedMesh only when each particle needs real geometry
• Push animation to the GPU via vertex shader using attributes like velocity and phase to avoid CPU loops
• Store per-particle data in Float32Array buffer attributes and mark needsUpdate only when necessary
• Disable depthWrite and use additive blending for glowing particle visuals and faster compositing
• Use size attenuation and device pixel ratio uniform for consistent on-screen sizing across displays

Example use cases

• A starfield with millions of tiny textured points using Points and a particle sprite atlas
• A galaxy or nebula visualization using procedural galaxyPositions and shader-driven motion
• Snow or rain where each particle wraps within bounds and animation runs in the vertex shader
• A swarm or flock using GPU velocity attributes and phase offsets for complex emergent motion
• Instanced glints or debris using InstancedMesh for small counts of 3D particle objects