Handling Initial Layer Setting Lag in Three.js

When you experience a frame freeze during the first call to camera.layers.set(), this is likely related to internal optimizations and initializations happening within Three.js's rendering pipeline.

Recommended Approaches

Pre-warm the Layers System

Running a dummy call during your initialization or loading screen is indeed a valid approach. This would trigger any one-time setup operations before your main rendering loop begins:

JAVASCRIPTCopied
// During initialization/loading
camera.layers.set(0); // Set to default layer
renderer.render(scene, camera); // Force a render cycle

// Later in your application
// camera.layers.set(1); // This should now be smoother

Alternative: Use Enable/Disable Instead

If you're toggling specific layers rather than setting the entire mask, you might find that using the enable/disable methods has different performance characteristics:

JAVASCRIPTCopied
// Instead of setting the entire mask
// camera.layers.set(layerNumber);

// Enable specific layers
camera.layers.enable(layerNumber);

// Or disable specific layers
camera.layers.disable(layerNumber);

Optimize Your Scene

Make sure objects in your scene are properly assigned to layers. Objects that share at least one layer with the camera will be rendered, so organizing your scene efficiently can help:

JAVASCRIPTCopied
// Assign objects to specific layers
object.layers.set(1);

Best Practices

1. Pre-warm the layers system during initialization
2. Consider batching layer changes when possible
3. Organize your scene objects into logical layer groups
4. Test performance with different approaches (set vs enable/disable)

The pre-warming approach during loading is perfectly acceptable and is commonly used to avoid these kinds of hiccups during the main application flow.