TITLE: Crab Angel Wing
NAME: Bill Newcum
COUNTRY: USA
EMAIL: bill@astconsulting.com
WEBPAGE: none
TOPIC: Internet Ray Tracing Competition, Stills
COPYRIGHT: I SUBMIT TO THE STANDARD RAYTRACING COMPETITION COPYRIGHT.
JPGFILE: crabsim.jpg
RENDERER USED: 
    POV-Ray for Windows v3.5

TOOLS USED: 
    Java simulation program
RENDERER TIME:  52 minutes

HARDWARE USED: 
    WinBook J4 laptop with 2 GHz Pentium IV and 512 Mb memory

IMAGE DESCRIPTION: 
    This picture is the result of a simulation of the motion
                    of a blue crab's front left leg.  My daughter was writing
                    a paper on the defense zone of the blue crab and had to
                    measure actual legs from crabs.  I suggested that she
                    also measure the angles of each joint, and offered to write
                    a simulation program that would create surfaces that
                    represent the movement of the tip of the crab leg.
                    The intermediate surfaces are artifacts of the simulation.
                    A crab can move its leg anywhere between the inner and
outer
                    surfaces.  The simulation showe that a crab cannot defend
                    its back.  This image may not be the most attractive in
your
                    collection, but it could fit into the "most unusual" 
                    category.  It illustrates a scientific use for rendering
                    programs.

DESCRIPTION OF HOW THIS IMAGE WAS CREATED: 
    Crab legs have 5 leg sections.
                    Each leg section has a hinged joint.  The Java simulation
program
                    builds a 3D model of a leg one section at a time, and
rotates
                    each joint a few degrees for each iteration of the
simulation.
                    The result of a single interation is a small patch, or
mesh.
                    After thousands of iterations that represent the full range
                    of motion in each joint, the combined meshes yielded a
                    the set of surfaces shown in the image.  A 2.3 Mb zip file
                    of the POV-Ray input model is available.  The POV-Ray model
                    includes multiple camera and light source combinations
                    that allow the image to be viewed from different angles.

