Procedural Animation Introduction to Procedural Methods in 3D Computer Animation Dr. Midori Kitagawa

In class Pay attention Take notes Learn Be ready for a pop quiz

Week 6: Modeling Basic modeling methods Assignment 12

Basic Modeling Methods Lofting Extrusion Sweeping Surface of evolution Boolean operations

Lofting Originated in boat design 2D cross-sections placed in 3D space are connected by side faces to form a 3D shape.

Extrusion Also called projection A copy of a 2D profile is made and translated and then the original and copied profiles are connected by side faces to form a 3D shape.

Sweeping 2D cross-section is swept along a 3D path to create a 3D shape. http://www.cs.princeton.edu/courses/archive/fall99/cs426/assignment4/assignment4.htm

Surface of revolution 2D profile is rotated around an axis to create a 3D shape. http://www.cs.princeton.edu/courses/archive/fall99/cs426/assignment4/assignment4.htm

Boolean operations Boolean operation -- union (or, “u”), intersection (and, “n”), or difference (not, “-”) -- is applied to a pair of objects. A u B A n B A - B B - A

Boolean operations Cookie SOP in Houdini Can produce a complicated object with a repeated used of operations. Prone to computational errors.

Assignment 12 Create 3D models of four or more different kinds of sea shells. At least two univalves and at least two bivalves. Color each model with at least two colors using Group SOPs. Make them as realistic as you can. http://www.cs.princeton.edu/courses/archive/fall99/cs426/assignment4/assignment4.htm