Drag object locked at certain distance/radius from camera view

问题

I have a camera in the center of the scene, 1 sphere at z=400 distance from the camera, with it's parent in the center.

I want to drag the sphere up/down/left/right from the view but at the same time not change it's z - position from the center.

回答1:

I ended up using another sphere and make it invisible, add side: THREE.DoubleSide to the material and use it for raycasting.

来源：https://stackoverflow.com/questions/19364909/drag-object-locked-at-certain-distance-radius-from-camera-view