visualization of 2d sheared particles by using vpython

st_visual.py

#/Applications/VPython-Py2.7/VIDLE.app/Contents/MacOS/Python
# coding=utf-8
from visual import *
import numpy
import sys

fin = open(sys.argv[1])

scene = display(title='Simple Shear',
                width=1100, height=800,
                background=color.gray(0.8), fullscreen=True)

line = fin.readline()
data = line.split()
np = int(data[1])
lx = float(data[3])
ly = float(data[4])
lz = float(data[5])

scene.fov = 0.1
#scene.ambient=(0.721879,0.721748,0.295551)
scene.ambient=(0.811841,0.319825,0.097166)
scene.cursor.visible = False
scene.forward = (0,0,-1)

particles1 = [ sphere(material=materials.marble ) for i in range(np) ]

rotaxis = [0,0,-1]
cnt = 0
angles = numpy.zeros(np)

while True:
	line = fin.readline()
	data = line.split()
	if len(data)==0:
		break
	disp = float(data[1])

	particle_data = numpy.fromfile(fin, dtype=float, sep=' ', count=(5*np))
	particle_data = particle_data.reshape((np, 5))
	positions_data = particle_data[:,[1,2]]

	if cnt == 0:
		radii = particle_data[:,4]
		for particle, position, radius in zip(particles1, positions_data, radii):
			particle.radius = radius
			particle.pos = [position[0], position[1], 0]
	else:
		angles = particle_data[:,3]-angles;
		for particle, position, ang in zip(particles1, positions_data, angles):
			particle.pos = [position[0], position[1], 0]
			particle.rotate(angle=ang, axis=(rotaxis))
	rate(15)

	cnt += 1
	angles = particle_data[:,3];
	# raw_input()
fin.close()