Abstract: Camera keyframing is an integral part of the animation making process. The animator places the camera in a sequence of "key" positions, and the computer produces a set of intermediate camera locations that interpolates between these keyframes. Camera keyframing traditionally treats the camera as just another 3D object in the scene, with intermediate frames produced by interpolating the position and focal point of the camera in space. Unlike a 3D object, however, the camera's role is to project the 3D scene into 2D. The animator indirectly controls the projection --- how objects in the scene are placed in the 2D image --- by adjusting the camera parameters for each keyframe. Automatic 3D camera interpolation adds yet another layer of indirection. The net effect is that the animator must solve a complicated inverse problem in order to move objects across the 2D scene in the desired manner.