３D格子状に配置した粒子をopenGLで可視化、マウスで視点移動

3次元格子状に配置した粒子をOpenGLで可視化する。
また視点をマウスドラックにより移動できるようにする。
配置粒子数は8000個。

以下は可視化しマウスで視点動かしている動画。
サンプルソースコードはページ下部に掲載。

Visualize particles arranged in a three-dimensional lattice with OpenGL.
Also make it possible to move the viewpoint by mouse drag.
The number of arranged particles is 8000.

import random
import math
from OpenGL.GL import *
from OpenGL.GLU import *
from OpenGL.GLUT import *


#Define xyz index
PX = 0
PY = 1
PZ = 2
VX = 3
VY = 4
VZ = 5
FX = 6
FY = 7
FZ = 8

#mouse move
mx = 0.0
my = 0.0

#lattice size
lsize = 1.0

#init pos is .. 20 * 20 * 20
PN    = 8000
th = math.pi * 0.5
ph = math.pi * 0.5

#ready to 9 parameters for particle 
#(PX, PY, PZ, VX, VY, VZ, FX, FY, FZ)
xyz   = [[0 for i in range(9)] for j in range(PN)]

def init_lattice():

  #dens^3 = PN
  dens = 20
  delt = lsize/dens;
  xv_sum = 0
  yv_sum = 0
  zv_sum = 0

  pnum = 0
  k = 0
  while k < dens:
    j = 0
    while j < dens:
      i = 0
      while i < dens:
        xyz[pnum][PX] = delt * i
        xyz[pnum][PY] = delt * j
        xyz[pnum][PZ] = delt * k
        pnum += 1
        i += 1
      j += 1
    k += 1

def draw():
    cx = cy = cz = lsize * 0.5
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)
    glClearColor(0.0, 0.0, 0.0, 1.0)

    glLoadIdentity()
    glColor3f(1.0,1.0,0.0)

    gluLookAt( 5*math.sin(th)*math.cos(ph)+cx,  5*math.cos(th)+cy,  5*math.sin(th)*math.sin(ph)+cz,\
            cx,  cy,  cz, -math.cos(th)*math.cos(ph),math.sin(th),-math.cos(th)*math.sin(ph) )

    glBegin(GL_LINE_LOOP)
    glVertex3d(0,0,0)
    glVertex3d(0,lsize,0)
    glVertex3d(lsize,lsize,0)
    glVertex3d(lsize,0,0)
    glEnd()
    glBegin(GL_LINE_LOOP)
    glVertex3d(0,0,lsize)
    glVertex3d(0,lsize,lsize)
    glVertex3d(lsize,lsize,lsize)
    glVertex3d(lsize,0,lsize)
    glEnd()
    glBegin(GL_LINES)
    glVertex3d(0,0,0)
    glVertex3d(0,0,lsize)
    glEnd()
    glBegin(GL_LINES)
    glVertex3d(0,lsize,0)
    glVertex3d(0,lsize,lsize)
    glEnd()
    glBegin(GL_LINES)
    glVertex3d(lsize,0,0)
    glVertex3d(lsize,0,lsize)
    glEnd()
    glBegin(GL_LINES)
    glVertex3d(lsize,lsize,0)
    glVertex3d(lsize,lsize,lsize)
    glEnd()

    nnum = 0
    while nnum < len(xyz):
       glPointSize(3.0)
       glColor3f(0.3, 0.3, 1.0)
       glBegin(GL_POINTS)
       glVertex3d(xyz[nnum][PX], xyz[nnum][PY], xyz[nnum][PZ])
       glEnd()
       nnum = nnum + 1

    glutSwapBuffers()


def init():
    glClearColor(0.7, 0.7, 0.7, 0.7)


def idle():
    glutPostRedisplay()


def reshape(w, h):
    glViewport(0, 0,w,h)
    glMatrixMode(GL_PROJECTION)
    glLoadIdentity()
    gluPerspective(30.0, w/h, 1.0, 100.0)
    glMatrixMode (GL_MODELVIEW)


def motion(x, y):
  global ph, th, mx, my

  dltx = mx -x
  dlty = my -y

  #Invalid large motion
  if 10 < abs(dltx):
   dltx = 0
  if 10 < abs(dlty):
   dlty = 0

  ph = ph - 0.01*dltx
  th = th + 0.01*dlty
  glutPostRedisplay()
  glutSwapBuffers()
  mx = x
  my = y


if __name__ == "__main__":
  init_lattice()

  glutInitWindowPosition(50, 50);
  glutInitWindowSize(340, 340);
  glutInit(sys.argv)
  glutInitDisplayMode(GLUT_RGBA | GLUT_DOUBLE )
  glutCreateWindow("pyOpenGL TEST")
  glutDisplayFunc(draw)
  glutReshapeFunc(reshape)
  glutMotionFunc(motion);
  init()
  glutIdleFunc(idle)
  glutMainLoop()

#end