rotation – Tarik Billa

Component of a quaternion rotation around an axis

May 17, 2023 by Tarik

There is an elegant solution for this problem, specially suited for quaternions. It is known as the “swing twist decomposition”: in pseudocode /** Decompose the rotation on to 2 parts. 1. Twist – rotation around the “direction” vector 2. Swing – rotation around axis that is perpendicular to “direction” vector The rotation can be composed … Read more

threejs how to rotate around object’s own center,instead of world center

February 28, 2023 by Tarik

If your mesh is not rotating around its center, it is because the geometry vertices are offset from the origin. You can automate repositioning by using a bounding box to define a reasonable center, and then offset the mesh’s position like so: var box = new THREE.Box3().setFromObject( mesh ); box.center( mesh.position ); // this re-sets … Read more