Summary

• Adds picking support for Gaussian Splats in unified rendering mode
• Introduces centralized PickerId class for consistent ID allocation across pickable objects
• Extends the Picker class to return GSplatComponent for unified gsplats alongside MeshInstance for other objects

Changes

Centralized ID Generation

• New PickerId class (src/scene/picker-id.js) with static get() method for allocating unique IDs
• MeshInstance now uses PickerId.get() instead of internal counter
• GSplatComponent allocates its own ID at construction, passed to placement

GSplat Unified Picking

• GSplatParams.id property enables per-component ID storage in the work buffer
• When enabled, a pcId stream (R32U format) is added to the work buffer format

Picker Updates

• Picker.getSelection() and getSelectionAsync() now return (MeshInstance | GSplatComponent)[]

Examples

• Updated gaussian-splatting/picking.example.mjs to demonstrate unified picking
• Created gaussian-splatting-legacy/picking.example.mjs for non-unified picking reference

Public API Changes

New: GSplatParams.id

// Enable gsplat ID for unified picking
app.scene.gsplat.id = true;

Once enabled, cannot be disabled. The ID stream persists for the lifetime of the app.

Updated: Picker.getSelectionAsync() / Picker.getSelection()

Return type changed from MeshInstance[] to (MeshInstance | GSplatComponent)[]:

picker.getSelectionAsync(x, y, 1, 1).then((results) => {
    const picked = results[0];
    if (picked instanceof pc.GSplatComponent) {
        // Unified gsplat component
        console.log('Picked gsplat:', picked.entity.name);
    } else {
        // MeshInstance
        console.log('Picked mesh:', picked.node.name);
    }
});