procedure sbtsur

This subroutine plots a semi-transparent iso-surface through a unit-cell of density. All (x,y,z) values are taken to be given in world coordinates. The z-component of the eye-poisition should be positive and that of all the lattice-vertices should be negative; the viewing-screen is fixed at z=0.

Syntax
sbtsur EYE,LATICE,DENS,N1,N2,N3,DSURF,IC1,IC2,LIGHT,LSHINE,ITRANS

Arguments

ARGUMENT    TYPE I/O DIMENSION DESCRIPTION

EYE:   R*4 I 3 (x,y,z) coordinate of eye-position.

LATICE:   R*4 I 3 x 4 (x,y,z) coordinates of the origin

   and the a, b & C lattice-vertices.

DENS:   R*4 I (N1+1) The density at regular points within

   x (N2+1) the unit cell, wrapped around so

   x (N3+1) that DENS(0,J,K)=DENS(N1,J,K) etc..

N1,N2,N3:   I*4 I - The dimensions of the unit-cell grid.

DSURF:   R*4 I - Density for the iso-surface.

IC1,IC2:   I*4 I - Lowest & highest colour-index to be

   used for the shading.

LIGHT:   R*4 I 3 (x,y,z) direction of flood-light.

LSHINE:   L*1 I - Shiny surface if TRUE, else diffuse.

ITRANS:   I*4 I - Level of transparency:

   1 = 25%; 2 = 50%; 3 = 75%.

ARGUMENT	TYPE I/O DIMENSION DESCRIPTION
EYE:	R*4 I 3 (x,y,z) coordinate of eye-position.
LATICE:	R*4 I 3 x 4 (x,y,z) coordinates of the origin
	and the a, b & C lattice-vertices.
DENS:	R*4 I (N1+1) The density at regular points within
	x (N2+1) the unit cell, wrapped around so
	x (N3+1) that DENS(0,J,K)=DENS(N1,J,K) etc..
N1,N2,N3:	I*4 I - The dimensions of the unit-cell grid.
DSURF:	R*4 I - Density for the iso-surface.
IC1,IC2:	I*4 I - Lowest & highest colour-index to be
	used for the shading.
LIGHT:	R*4 I 3 (x,y,z) direction of flood-light.
LSHINE:	L*1 I - Shiny surface if TRUE, else diffuse.
ITRANS:	I*4 I - Level of transparency:
	1 = 25%; 2 = 50%; 3 = 75%.