usage: xfpp3d [-h] [-c] [-s] [-w]

Displays animations of three dimensional particle motion.

   Options: -h   Displays this help message.
            -c   Enables user-specified coloring (RGB) of particles.
            -s   Renders particles as solid spheres.
            -w   Renders particles as wireframe spheres.

xfpp3d reads ASCII input from standard input in one of the following
two formats:

(Note that ! denotes the start of a comment.)

FORMAT 1: Default (all particles displayed in single, fixed color)

       <np>                            ! Number of particles
       <size_1>                        ! Display size of particle 1
       <size_2>                        ! Display size of particle 2
                   .
                   .
                   .
       <size_np>                       ! Display size of particle np
       <t_1>                           ! First display time
       <x_1_1>  <y_1_1>  <z_1_1>       ! Coordinates of particle 1 at t_1
       <x_1_2>  <y_1_2>  <z_1_2>       ! Coordinates of particle 2 at t_1
                   .
                   .
                   .
       <x_1_np> <y_1_np> <z_1_np>      ! Coordinates of particle np at t_1
       <t_2>                           ! Second display time
       <x_2_1>  <y_2_1>  <z_2_1>       ! Coordinates of particle 1 at t_2
       <x_2_2>  <y_2_2>  <z_2_2>       ! Coordinates of particle 2 at t_2
                   .
                   .
                   .
       <x_2_np> <y_2_np> <z_2_np>      ! Coordinates of particle np at t_2
       <t_3>                           ! Third display time
                   .
                   .
                   .

  All values are expected to be real numbers except for <np> which is
  an integer.

FORMAT 2: User-specified coloring (enabled via -c option).  Colors are specfied 
          as RGB (red-green-blue) triples, where each color component is a 
          real number between 0.0 and 1.0.

       <np>                            ! Number of particles
       <size_1> <R_1> <G_1> <B_1>      ! Display size and color of part. 1
       <size_2> <R_2> <G_2> <B_2>      ! Display size and color of part. 2
                   .
                   .
                   .
       <size_np> <R_np> <G_np> <B_np>  ! Display size and color of part. np
       <t_1>                           ! First display time
       <x_1_1>  <y_1_1>  <z_1_1>       ! Coordinates of particle 1 at t_1
       <x_1_2>  <y_1_2>  <z_1_2>       ! Coordinates of particle 2 at t_1
                   .
                   .
                   .
       <x_1_np> <y_1_np> <z_1_np>      ! Coordinates of particle np at t_1
       <t_2>                           ! Second display time
       <x_2_1>  <y_2_1>  <z_2_1>       ! Coordinates of particle 1 at t_2
       <x_2_2>  <y_2_2>  <z_2_2>       ! Coordinates of particle 2 at t_2
                   .
                   .
                   .
       <x_2_np> <y_2_np> <z_2_np>      ! Coordinates of particle np at t_2
       <t_3>                           ! Third display time
                   .
                   .
                   .
  All values are expected to be real numbers except for <np> which is
  an integer.