Setup 3D projection

def on_resize(width, height):
	"""Setup 3D projection"""
	glViewport(0, 0, width, height)
	glMatrixMode(GL_PROJECTION)
	glLoadIdentity()
	gluPerspective(30, 1.0*width/height, 0.1, 1000.0)
	glMatrixMode(GL_MODELVIEW)
	glLoadIdentity()