The Camera Map modifier (world-space version) lets you blend an object into the background throughout the course of an animation.
The Camera Map world-space modifier is similar to the Camera Map object-space modifier, in that it applies UVW mapping coordinates to the object based on a specified camera. As a result, if you assign the same map as a Screen environment to the background as you apply to the object, the object is invisible in the rendered scene.
Names the current camera used for mapping. If there is no current camera, reads "None."
Click this button, and then select the camera you want used for mapping.
Specifies use of a map channel. Map channels are specified in the Material Editor.
Specifies use of the Vertex Color Channel (see UVW Map Modifier).