ClothObject.py
from OpenGL.GLUT import *
from OpenGL.GL import *
from OpenGL.GLU import *
import numpy as np
import math
class ClothObject :
def __init__(self, sizeX, sizeZ, nW, nH):
self.dx = sizeX / (nW-1)
self.dz = sizeZ / (nH-1)
self.dDiag = math.sqrt(self.dx**2.0 + self.dz**2.0)
self.nW, self.nH = nW, nH
self.clothSize = (sizeX, sizeZ)
# vertex array (x,y,z)
self.verts = np.zeros(shape=(nW * nH, 3))
self.velocity = np.zeros(shape=(nW*nH, 3))
# spring links (i, j)
self.springs = \
np.zeros(shape=((nW - 1) * nH + (nH - 1) * nW + (nW - 1) * (nH - 1) * 2, 2),
dtype=np.int32)
# relaxed length of spring : l0
self.l0 = np.zeros(shape=(len(self.springs),))
self.numXSprings = (self.nW - 1) * self.nH
self.numZSprings = (self.nH - 1) * self.nW
self.numDiagonalSprings = (self.nW - 1) * (self.nH - 1)
self.resetMassSpring()
def resetMassSpring(self):
for i in range(0, self.nW * self.nH):
self.verts[i] = [(i % self.nW) * self.dx, 1, (int(i / self.nW)) * self.dz]
self.velocity[i] = [0,0,0]
for i in range(0, self.numXSprings):
row = int(i / (self.nW - 1))
col = i % (self.nW - 1)
self.springs[i] = [row * self.nW + col, row * self.nW + col + 1]
self.l0[i] = self.dx
for i in range(0, self.numZSprings):
row = int(i / (self.nW))
col = i % (self.nW)
self.springs[self.numXSprings + i] = \
[row * self.nW + col, (row + 1) * self.nW + col]
self.l0[(self.nW - 1) * self.nH + i] = self.dz
for i in range(0, self.numDiagonalSprings):
row = int(i / (self.nW - 1))
col = i % (self.nW - 1)
self.springs[self.numXSprings + self.numZSprings + 2 * i] \
= [row * self.nW + col,(row + 1) * self.nW + col + 1]
self.l0[self.numXSprings + self.numZSprings + 2 * i] = self.dDiag
self.springs[self.numXSprings + self.numZSprings + 2 * i + 1] \
= [row * self.nW + col + 1,(row + 1) * self.nW + col]
self.l0[self.numXSprings + self.numZSprings + 2 * i + 1] = self.dDiag
def drawSpring(self):
glColor3f(1, 1, 1)
glBegin(GL_LINES)
for i in range(0, len(self.springs)) :
idx0 = self.springs[i][0]
idx1 = self.springs[i][1]
loc0 = self.verts[idx0]
loc1 = self.verts[idx1]
glVertex3fv(loc0)
glVertex3fv(loc1)
glEnd()
def update(self, dt):
numParticles = self.nW * self.nH
gravity = np.array([0.0, -9.8, 0.0])
for i in range (0, numParticles) :
self.velocity[i] = self.velocity[i] + gravity * dt
self.verts[i] = self.verts[i] + self.velocity[i]*dt
#### Simple Euler method for gravity simulation
main.py
import wx # requires wxPython package
from wx import glcanvas
from OpenGL.GL import *
from OpenGL.GLU import *
import ClothObject
class MyFrame(wx.Frame) :
def __init__(self):
self.size = (1280, 720)
wx.Frame.__init__(self, None, title = "wx frame", size = self.size,
style = wx.DEFAULT_FRAME_STYLE ^ wx.RESIZE_BORDER)
self.panel = MyPanel(self)
class MyPanel(wx.Panel) :
def __init__(self, parent):
wx.Panel.__init__(self, parent)
self.canvas = OpenGLCanvas(self)
self.bAnimation = False
self.ResetButton = wx.Button(self, wx.ID_ANY, "Mass-Spring Reset",
pos=(1030, 20), size=(200,40), style=0 )
self.AnimationButton = wx.Button(self, wx.ID_ANY, "Animate/Stop",
pos=(1030, 60), size=(200, 40), style=0)
self.stiffnessLabel = wx.StaticText(self, -1, pos=(1030, 150), style=wx.ALIGN_CENTER)
self.stiffnessLabel.SetLabel("Stiffness")
self.stiffnessSlider = wx.Slider(self, -1, pos=(1030, 180), size=(200,50),
style = wx.SL_HORIZONTAL|wx.SL_AUTOTICKS,
value=0, minValue=-5, maxValue = 5)
self.stepLabel = wx.StaticText(self, -1, pos=(1030, 250), style=wx.ALIGN_CENTER)
self.stepLabel.SetLabel("Time Step")
self.stepSlider = wx.Slider(self, -1, pos=(1030, 280), size=(200, 50),
style=wx.SL_HORIZONTAL | wx.SL_AUTOTICKS,
value=0, minValue=-5, maxValue=5)
self.Bind(wx.EVT_BUTTON, self.OnAnimationButton, self.AnimationButton)
self.Bind(wx.EVT_BUTTON, self.OnResetButton, self.ResetButton)
def OnAnimationButton(self, event) :
if self.bAnimation is False :
self.bAnimation = True
else :
self.bAnimation = False
self.canvas.bAnimation = self.bAnimation
def OnResetButton(self, event) :
self.canvas.clothObject.resetMassSpring()
class OpenGLCanvas(glcanvas.GLCanvas):
def __init__(self, parent) :
self.initialized = False
self.size = (1024,720)
self.aspect_ratio = 1
glcanvas.GLCanvas.__init__(self, parent, -1, size = self.size)
self.context = glcanvas.GLContext(self)
self.SetCurrent(self.context)
self.Bind(wx.EVT_PAINT, self.OnDraw)
self.Bind(wx.EVT_IDLE, self.OnIdle)
self.InitGL()
self.clothObject = ClothObject.ClothObject(1,1,5,5)
self.bAnimation = False
def InitGL(self):
glMatrixMode(GL_PROJECTION)
glLoadIdentity()
self.aspect_ratio = float(self.size[0]) / self.size[1]
gluPerspective(60, self.aspect_ratio, 0.1, 100.0)
glViewport(0,0,self.size[0], self.size[1])
def OnDraw(self, event):
# clear color and depth buffers
if not self.initialized :
self.InitGL()
self.initialized = True
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)
# position viewer
glMatrixMode(GL_MODELVIEW)
glLoadIdentity()
gluLookAt(2,2,2, 0,0,0, 0,1,0)
self.clothObject.drawSpring()
self.SwapBuffers()
def OnIdle(self, event):
if self.bAnimation :
self.clothObject.update(0.01)
self.Refresh()
def main() :
app = wx.App()
frame = MyFrame()
frame.Show()
app.MainLoop()
if __name__ == "__main__" :
main()