Object Space - approaches for visible surface determination

The second approach as object-space that compares all objects directly along with each other inside the scene definition and removes those objects or portion of objects which are not visible. In terms of pseudo-code, we comprise:

    for (each object in the world) 

        {

            determine those parts of the object whose view is unobstructed (not blocked)

by other

             parts of it or any other object;

             draw those parts in the appropriate color;

         }

This approach compares all of the n objects to itself and to another objects, and discarding unseen portions. Hence, the computational effort is proportional to n².