threejs-syntax-geometries

Construct custom 3D shapes by defining vertex positions and attributes within BufferGeometry using BufferAttribute. You can build indexed or non-indexed geometry from scratch to render complex web-based 3D meshes.

Indexed geometry reuses vertices via an index buffer to optimize rendering, while non-indexed geometry defines separate vertices for every triangle. Choosing between them impacts rendering performance and memory usage for 3D shapes.

Render thousands of objects efficiently using InstancedMesh to draw identical geometries in a single draw call. This approach applies per-instance attributes to optimize performance for large-scale 3D scenes.

Yes, you can extrude 2D shapes into 3D geometries and animate them using morph targets. Three.js provides built-in geometries and utilities to handle shape extrusion and per-geometry attribute modifications.

Built-in Three.js geometries cover 21 standard shapes but lack complex composite structures. For multi-material complex scenes, you must use grouping and draw ranges to manage rendering limitations and maintain performance.

Proper geometry disposal matters because failing to dispose of BufferGeometry causes memory leaks in WebGL applications. You must explicitly dispose of geometries when they are no longer needed to free GPU memory resources.