#### 7.2.21 camera-prop

`(camera-prop { geometry object } [projective])`
  Specify the object to be shown when drawing other cameras. By default, this object is drawn with its origin at the camera, and with the camera looking toward the object's -Z axis. With the `projective` keyword, the camera's viewing projection is also applied to the object; this places the object's Z=-1 and Z=+1 at near and far clipping planes, with the viewing area -1<={X,Y}<=+1. Example: (camera-prop { < cube } projective)