feat: animation

src/core/math/normalToEuler.ts

@@ -0,0 +1,14 @@
+import { Euler, Quaternion, Vector3 } from 'three';
+import { J_HAT } from '../../constants/axis';
+
+const quaternion = new Quaternion();
+const axis = new Vector3();
+
+export function normalToEuler(normal: Vector3, up = J_HAT) {
+  return new Euler().setFromQuaternion(
+    quaternion.setFromAxisAngle(
+      axis.crossVectors(up, normal).normalize(),
+      up.angleTo(normal),
+    ),
+  );
+}