Three.js - what do the matrices in a 3D object represent

Question

Looking at the source of THREE.Object3D, there are three properties: matrix, matrixWorld and matrixRotationWorld.

I see that the o

Answer 1

object.matrix is the matrix transform of the object.

object.matrixWorld is the matrix transform of the object, taking into consideration the matrix transform of the object's parent. (The object's parent may also have a parent, so the calculation of object.matrixWorld is recursive.)

object.matrix and object.matrixWorld are identical when the object has no parent, other than the scene.

object.matrixRotationWorld no longer exists.

three.js r.69