######################################################################
# Python Open Dynamics Engine Wrapper
# Copyright (C) 2004 PyODE developers (see file AUTHORS)
# All rights reserved.
#
# This library is free software; you can redistribute it and/or
# modify it under the terms of EITHER:
# (1) The GNU Lesser General Public License as published by the Free
# Software Foundation; either version 2.1 of the License, or (at
# your option) any later version. The text of the GNU Lesser
# General Public License is included with this library in the
# file LICENSE.
# (2) The BSD-style license that is included with this library in
# the file LICENSE-BSD.
#
# This library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the files
# LICENSE and LICENSE-BSD for more details.
######################################################################
# PyODE Example: Transforms
# This example demonstrates the way object transforms are calculated relative
# to the parent element's transform in XODE.
from OpenGL.GL import *
from OpenGL.GLU import *
from OpenGL.GLUT import *
from cgtypes import *
import pygame
import math
import ode
import xode.parser
doc = '''<?xml version="1.0" encoding="iso-8859-1"?>
<xode>
<world name="world1">
<space name="space1">
<body>
<transform>
<position x="0" y="0" z="0"/>
<rotation>
<euler x="0" y="0" z="0" aformat="degrees"/>
</rotation>
</transform>
<!-- Y-axis Rotations -->
<body>
<transform scale="1.25">
<position x="0" y="1" z="0"/>
<rotation>
<euler x="0" y="30" z="0" aformat="degrees"/>
</rotation>
</transform>
<body>
<transform scale="1.25">
<position x="0" y="1" z="0"/>
<rotation>
<euler x="0" y="30" z="0" aformat="degrees"/>
</rotation>
</transform>
</body>
</body>
<!-- X-axis Rotations -->
<body>
<transform scale="1.25">
<position x="1" y="0" z="0"/>
<rotation>
<euler x="30" y="0" z="0" aformat="degrees"/>
</rotation>
</transform>
<body>
<transform scale="1.25">
<position x="1" y="0" z="0"/>
<rotation>
<euler x="30" y="0" z="0" aformat="degrees"/>
</rotation>
</transform>
</body>
</body>
<!-- Z-axis Rotations -->
<body>
<transform scale="1.25">
<position x="0" y="0" z="-1"/>
<rotation>
<euler x="0" y="0" z="30" aformat="degrees"/>
</rotation>
</transform>
<body>
<transform scale="1.25">
<position x="0" y="0" z="-1"/>
<rotation>
<euler x="0" y="0" z="30" aformat="degrees"/>
</rotation>
</transform>
</body>
</body>
</body>
</space>
</world>
</xode>
'''
def prepare_GL(c):
"""Prepare drawing.
"""
# Viewport
glViewport(0, 0, 640, 480)
# Initialize
glClearColor(0.8, 0.8, 0.9, 0)
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glEnable(GL_DEPTH_TEST)
glDisable(GL_LIGHTING)
glEnable(GL_LIGHTING)
glEnable(GL_NORMALIZE)
glShadeModel(GL_FLAT)
# Projection
glMatrixMode(GL_PROJECTION)
glLoadIdentity()
P = mat4(1).perspective(45,1.3333,0.2,20)
glMultMatrixd(P.toList())
# Initialize ModelView matrix
glMatrixMode(GL_MODELVIEW)
glLoadIdentity()
# Light source
glLightfv(GL_LIGHT0,GL_POSITION,[0,0,1,0])
glLightfv(GL_LIGHT0,GL_DIFFUSE,[1,1,1,1])
glLightfv(GL_LIGHT0,GL_SPECULAR,[1,1,1,1])
glEnable(GL_LIGHT0)
# View transformation
V = mat4(1).lookAt(1.2*vec3(0.5*c,0.7*c,c),(1.0,1.0,0), up=(0,1,0))
V.rotate(math.pi,vec3(0,1,0))
V = V.inverse()
glMultMatrixd(V.toList())
def draw_body(body):
"""Draw an ODE body.
"""
x,y,z = body.getPosition()
R = body.getRotation()
T = mat4()
T[0,0] = R[0]
T[0,1] = R[1]
T[0,2] = R[2]
T[1,0] = R[3]
T[1,1] = R[4]
T[1,2] = R[5]
T[2,0] = R[6]
T[2,1] = R[7]
T[2,2] = R[8]
T[3] = (x,y,z,1.0)
glPushMatrix()
glMultMatrixd(T.toList())
if body.shape=="box":
sx,sy,sz = body.boxsize
glScale(sx, sy, sz)
glutSolidCube(1)
glPopMatrix()
######################################################################
# Initialize pygame
passed, failed = pygame.init()
# Open a window
srf = pygame.display.set_mode((640,480), pygame.OPENGL | pygame.DOUBLEBUF)
root = xode.parser.Parser().parseString(doc)
world = root.namedChild('world1').getODEObject()
world.setGravity( (0, 0, 0) )
# Add all ODE bodies from the XODE document into bodies.
def transverse(node):
obj = node.getODEObject()
if (isinstance(obj, ode.Body)):
# Set attributes for draw_body()
obj.shape = 'box'
obj.boxsize = (0.4, 0.4, 0.4)
bodies.append(obj)
for node in node.getChildren():
transverse(node)
bodies = []
transverse(root)
# Some variables used inside the simulation loop
fps = 50
dt = 1.0/fps
counter = 0.0
running = True
clk = pygame.time.Clock()
while running:
events = pygame.event.get()
for e in events:
if e.type==pygame.QUIT:
running=False
if (counter < 5):
counter = counter + 0.1
# Draw the scene
prepare_GL(counter)
for b in bodies:
draw_body(b)
pygame.display.flip()
# Simulate
n = 2
for i in range(n):
world.step(dt/n)
clk.tick(fps)
