Rendering Millions of Particles in Three.js

Rendering 20-30 million particles is a significant challenge for any web-based 3D engine, including Three.js. While Three.js is powerful, there are several approaches you might consider to improve performance:

Optimization Strategies

1. Level of Detail (LOD) Techniques

   • Render fewer particles when the camera is far away
   • Cluster nearby particles when zoomed out
   • Only render particles in the camera's view frustum

2. Use WebGL Instancing

   • This can be more efficient than standard Points for large numbers of particles
   • Requires custom shaders but can significantly improve performance

3. Chunking/Partitioning

   • Split your particles into manageable chunks (e.g., 100k each)
   • Only render chunks that are visible to the camera

4. Use WebGLRenderer Optimizations

   • Ensure you're using the most efficient renderer settings
   • Consider using WebGLRenderTarget for off-screen rendering if applicable

5. Custom Shaders

   • Write custom GLSL shaders to handle the particle rendering more efficiently
   • This gives you more control over the rendering pipeline

Specialized Solutions

For truly massive point clouds (20-30 million particles), you might need specialized solutions:

1. Potree is indeed designed specifically for large point clouds and uses octree-based level of detail, which could be appropriate for your use case.

2. Consider using WebGL2 features if available, which can provide better performance.

3. Data Streaming - Load only the particles that are needed at any given time, streaming in more detail as the user zooms in.

Renderer Considerations

Three.js offers several renderers that might be relevant:

• WebGLRenderer - The standard renderer, which you're likely already using
• WebGLRenderTarget - For off-screen rendering, which might be useful for complex pre-processing

Conclusion

For 20-30 million particles, you'll likely need a combination of:

1. Algorithmic optimizations (LOD, frustum culling)
2. Custom WebGL/GLSL code
3. Possibly a specialized library like Potree

If you want to stick with Three.js, start by implementing LOD techniques and custom shaders. If that's still not sufficient, then exploring Potree or other specialized point cloud libraries would be a reasonable next step.