How to position and rotate an object so that it fits a box on my camera view?

[trusktr]

See this thread, and this comment, for how to calculate distance from camera to fit an object in the camera viewport:

Functions to calculate the visible width / height at a given z-depth from a perspective camera

In case it helps anyone, here’s how to fit an object (most likely a flat plane) on the screen so that it “fits” depending on aspect ratio. For example, if we have an object taller than it is wide we want the Y dimension (the tall dimension) to fit within the view, but if the object is wider than it is tall we want the X dimension (the width dimension) to fit within view. The following distanceToFitObjectToView function will tell you at what distance to place the object so that it fits within vi…