TITLE: Chalice
NAME: Jim Charter
COUNTRY: USA
EMAIL: jrcsurvey@aol.com
TOPIC: Worship
COPYRIGHT: I SUBMIT TO THE STANDARD RAYTRACING COMPETITION COPYRIGHT.
JPGFILE: chalice1.jpg
RENDERER USED: 
    MegaPOV6a

TOOLS USED: 
    Photoshop, sPatch, Spline.inc by Chris Colefax

RENDER TIME: 
    38 min parse 14 min render

HARDWARE USED: 
    p3 800 256Mg

IMAGE DESCRIPTION: 

At one time argued to be the "Holy Grail", this medieval
relique was found at the site of Antioche. It's gold-leaf 
silverwork depicts Christ and the Apostles.  It is in the 
collection of the Metropolitan Museum of Art in NY

DESCRIPTION OF HOW THIS IMAGE WAS CREATED: 

The cup and relief effect was created with a mesh.  The cup was shaped using
splines.

A diagram of the relinqary was found in a book discussing the Antioche find. 
The diagram was projected in a
curved or arched shape like the swath a windshield-wiper makes. This would wrap,
in three dimensions, around a funnel shape. It was used by the diagrammer to
approximate the attenuated form of the chalice. I xeroxed this diagram then
scanned it.  I painted the result in Photoshop to create a result what could
act like a conventional heightfield.  I then swept this image-map using
eval_pigment and created a file of values which would recreate the relief.
These values were multipled by the surface normals of the cup then added to the
cup's
surface points to provide vertex points for the triangles of the mesh.

The stem of the relique is a lathe.  The base is torii.  The texture of the stem
is a conventional bump_map normal based on a hand-drawn texture.  It was the
only thing I could get to work adequately against the steep curves of the
lathe.

The cloth display is modelled in sPatch