I've been playing with three.js for few weeks now and got few inconsistencies on ray casting. Here is a simplified version demonstrating one of the bug I encoutered : http://jsfiddle.net/eMrhb/12/ The camera is added to the sphere mesh for further use of TrackBallControl for example. scene.add(mesh); mesh.add(camera); Clicking a few times on the sphere and opening the console, show us none of the expected intersections between the ray and the mesh. Adding the camera to the scene (http://jsfiddle.net/eMrhb/9/), solves the problem: scene.add(mesh); scene.add(camera); But I could use a much more complex hierarchy between my scene objects and the camera to suit my needs. Is this a limitation? If it is, is there any workarounds I could use?