Method and apparatus for controlling shadow geometry on computer displays

In an interactive computer-controlled display system, a method for automatically generating and manipulating shadow geometry, said method comprising the steps of:

• maintaining primary element information defining a first primary element;
• maintaining primary element information defining a second primary element;
• combining said first primary element and said second primary element;
• generating shadow geometry information defining said shadow geometry, said shadow geometry information having a predetermined mathematical relationship with said combination of said first primary element and said second primary element, said shadow geometry information being generated in response to user manipulation of said combination of said first primary element and said second primary element;
• integrating said shadow geometry with said primary and secondary elements to form a single graphical par unit;
• and
• selectively displaying said graphical par unit.

An interactive computer-controlled display apparatus for automatically generating and manipulating shadow geometry, said apparatus comprising:

• means for maintaining primary element information defining a primary element;
• means for generating shadow geometry information defining said shadow geometry, said shadow geometry having a predetermined mathematical relationship with said primary element, said shadow geometry information being generated in response to user manipulation of said primary element;
• means for integrating said shadow geometry with said primary element to form a single graphical par unit;
• and
• means for selectively displaying said graphical par unit.

An interactive computer-controlled display apparatus for automatically generating and manipulating shadow geometry, said apparatus comprising:

• means for maintaining primary element information defining a first primary element,
• means for maintaining primary element information defining a second primary element;
• means for combining said first primary element and said second primary element;
• means for generating shadow geometry information defining said shadow geometry, said shadow geometry information having a predetermined relationship with said combination of said first primary element and said second primary element, said shadow geometry information being generated in response to user manipulation of said combination of said first primary element and said second primary element;
• integrating said shadow geometry with said primary and secondary geometry to form a single graphical par unit, and means for selectively displaying said graphical par unit.