After the object which will be projected on is chosen or created, software is used to map the corners of the video to the surfaces. First, one must choose the images or video to project. Then, place each video on to its designated surface. alternatively one may choose to map the entire scene in 3d and attempt to project and mask the image back onto its framework. The next step is defined as "masking," which means using opacity templates to actually "mask" the exact shapes and positions of the different elements of the building or space of projection. In 3d Mapping, coordinates need to be defined for where the object is placed in relation to the projector, the xyz orientation, position and lens specification of the projector must be determined virtual scene.