如何在Three.js中从任何摄像机角度实现ZoomAll功能？

Question

I have a scene with many Object3D objects containing blocks, cylinders and meshes. I also have a perspective camera and use trackballcontrols. What I need is a way to set the camera position without modifying the FOV or the camera angle and insure that all objects in the scene are visible on screen. I have successfully done this with preset top, bottom, left and right views using the bounding box of the entire scene, but I need this to work from any camera angle since the user can rotate the view using trackball controls into any position.

If there were a way to get a 2d bounding rectangle based on the camera position, target and the list of objects, I think I could get it to work, but I am having trouble finding how to do this.

The functionality would work like this: With a scene containing many objects, the user rotates the camera with the mouse to some arbitrary position and then clicks a "Zoom All" button. Then, the camera is zoomed(moved) out or in(keeping FOV constant) to make all objects fit to the screen.

Answer 1

How about rotate and translate the whole szene, so that the camera lies on an axis looking at the origin.

From there get the bounding box, calculate the needed distance for the camera and translate the camera.

Then rotate and translate the whole szene back.