This directory contains six simple models described as NURBS.  Each file
contains the following notice, followed by one or more spline surface
descriptions:

	These models were created using the Alpha_1 geometric
	modeling system at the Computer Science Department,
	University of Utah.  We would appreciate your
	acknowledging the source of the data in publication
	of work utilizing these models, or portions of them.

The text format in which these models are distributed is intended to be mashed
into whatever form you want in order to read the data into your own software.
No parser or filters for this text form is (nor will be) provided by the
University of Utah.

The spline surfaces are in the following format:

	    object = srf_obj	/* { */
	    s_mesh = 
		object = matrix_obj	/* { */
		pt_tag = E3
		total = 195
		size[3] = 13 5 3
		value[195] = -5.41795 .25 .733713
				...
			    3 -.25 0

		endobject 	/* matrix_obj} */
	    s_knot_vector[2] =
		object = matrix_obj	/* { */
		pt_tag = SCALAR
		total = 9
		size[3] = 1 9 1 
		value[9] = 0 0 0 0 .5
			    1 1 1 1 
		endobject 	/* matrix_obj} */


		object = matrix_obj	/* { */
		pt_tag = SCALAR
		total = 17
		size[3] = 1 17 1 
		value[17] = 0 0 0 0 .5
			    1 1.5 2 2.5 3
			    3.5 4 5 6 6
			    6 6 
		endobject 	/* matrix_obj} */


	    s_order[2] = 4 4 
	    s_end_conditions[2] = EC_OPEN EC_OPEN
	    endobject 	/* srf_obj} */

The surface control mesh ("s_mesh"), and two knot vectors ("s_knot_vector[2]")
are described as sub-objects of a general type "matrix_obj".  The first knot
vector is associated with the rows of the control mesh, the second with the
columns.  Knot vectors are given explicitly, with duplicate values to indicate
multiple knots.  The "s_order[2]" field indicates the polynomial order
(degree+1) of the surface in the row and column direction respectively.  The
"s_end_conditions[2]" field indicates the end condition type associated with
the row and column direction of the surface respectively.  It may be one of
EC_OPEN, EC_FLOATING, and EC_PERIODIC.

The "pt_tag" field of a matrix object describes the elements.  It is one of
SCALAR for scalar values, E2 or E3 for euclidean 2- or 3-space points, P2 or
P3 for projective 2- or 3-space points.  The "total" field indicates the total
number of floating point numbers are in the matrix.  The "size[3]" field
describes the dimensions of the matrix; the third dimension agrees with the
dimensionality indicated by the "pt_tag" field.

________________________________________________________________


The Alpha_1 geometric modeling system is licensed to Universities for a small
distribution fee.  For information about obtaining Alpha_1 (*not* about the
data in this distribution) contact:

	Glenn McMinn
	Engineering Geometry Systems
	275 E. South Temple, Suite 305
	Salt Lake City, UT  84111
	(801) 575-6021
	mcminn@cs.utah.edu