procedure sbsurf
This subroutine plots an 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
sbsurf EYE,LATICE,DENS,N1,N2,N3,DSURF,IC1,IC2,LIGHT,LSHINE
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. |