Anamorphoses are distorted images that need to be seen from a special
point of view in order to reconstruct the correct image (perspectival
anamorphosis). In catoptric anamorphoses, a mirror is used to restore
the original image. We describe an effective procedure, using
ray-tracing software, to define, test and build general catoptric
anamorphoses. Users can define the mirror's shape, the surface on
which the distorted image lays, and set the observer's point of
view.
The method can be used to virtually render and test anamorphoses
designs or to output a distorted image in any suitable image format
that can be printed at any scale, to obtain a real size version of
the anamorphosis. We show examples with different mirrors and
different distorted image surfaces.