WEB: COLORED SURFACES

Colored Surface-- Display a surface view with colored voxels   6/21/95

PURPOSE:  Display a shaded surface from a volume and color the voxels
          which appear on the surface according to colors specified in
          a second color volume.

 USAGE:   Similar to the surface operation,  except that the user is
          prompted for both the SPIDER volume to be surfaced and a 
          second SPIDER volume which contains a color assignment for 
          each voxel.  Both volumes must have the same dimensions.

          Colors should be 0 --> 7.  The more colors requested, the
          less the intensity range available within each color.  For 
          three colors about 58 intensities are available.  
          Currently the opteration will load a default color assignment
          as follows:  0 = blue,  1 = green,   2 = red,  3 = yellow,
                       4 = cyan,  5 = magenta, 6 = white. 
          The actual color can be changed by creating and loading
          a colormap having a intensity ramp for each of the desired 
          colors.  For example, with the following web output:
          Number of colors:3   Initial lut index: 64 Indices/color: 58;
          you should create a color-look-up-table having
          colors for specified indices as follows:
                 64  r0  g0 b0     | 
                 65  r1  g1 b1     |
                  .                |  ( intensity ramp for color zero)
                  .                |  ( r*,g* & b* ar in range 0...255)
                121  r58 g58 b58   |

                122  r0  g0 b0     | 
                123  r1  g1 b1     |
                  .                |  ( intensity ramp for color one)
                  .                |  ( r,g, & b values are different
                179  r58 g58 b58   |     than above)

                180  r0  g0 b0     | 
                181  r1  g1 b1     |
                  .                |  ( intensity ramp for color two)
                  .                |
                137  r58 g58 b58   |


          Load the color-ramp using the "LUT" operation under "OPTIONS"


NOTE      The operation can also accept a arbitrarily ranged color volume
          and will automatically partition the color range into the number of
          colors requested in the surface munu.  However I do not recommend 
          this method of use, as it may disappear in the future.

NOTE:     This operation is still under construction and may not work 
          properly  twice in the same WEB session.  If you have problems 
          please restart WEB.