Chapter 530: ConvexObjectBreaker

Core Idea

This class can be used to subdivide a convex Geometry object into pieces.

Use the function prepareBreakableObject to prepare a Mesh object to be broken. Then, call the various functions to subdivide the object (subdivideByImpact, cutByPlane). Sub-objects that are product of subdivision don't need prepareBreakableObject to be called on them.

Requisites for the object:

Mesh object must have a buffer geometry and a material.
Vertex normals must be planar (not smoothed).
The geometry must be convex (this is not checked in the library). You can create convex geometries with ConvexGeometry. The BoxGeometry, SphereGeometry and other convex primitives can also be used.

Note: This lib adds member variables to object's userData member (see prepareBreakableObject function) Use with caution and read the code when using with other libs.

Code Examples

import { ConvexObjectBreaker } from 'three/addons/misc/ConvexObjectBreaker.js';

What it demonstrates: Typical usage of ConvexObjectBreaker.

Reference Tables

Constructor

Signature
`new ConvexObjectBreaker( minSizeForBreak : number, smallDelta : number )`

Methods

Method	Description
`.cutByPlane( object : Object3D, plane : Plane, output : Object ) : number`	Subdivides the given 3D object into pieces by a plane.
`.prepareBreakableObject( object : Object3D, mass : number, velocity : Vector3, angularVelocity : Vector3, breakable : boolean )`	Must be called for all 3D objects that should be breakable.
`.subdivideByImpact( object : Object3D, pointOfImpact : Vector3, normal : Vector3, maxRadialIterations : number, maxRandomIterations : number ) : Array.<Object3D>`	Subdivides the given 3D object into pieces by an impact (meaning another object hits the given 3D object at a certain surface point).

Key Takeaways

Key methods: cutByPlane, prepareBreakableObject, subdivideByImpact.

Connects To

Source: examples/jsm/misc/ConvexObjectBreaker.js