def runSimulation(sim):
# Create the collision shapes for the ball and ground.
cs_ball = SphereShape(1)
cs_ground = StaticPlaneShape(Vec3(0, 1, 0), 1)
# Create a Rigid Body for the static (ie mass=0) Ground.
q0 = Quaternion(0, 0, 0, 1)
ms = DefaultMotionState(Transform(q0, Vec3(0, -1, 0)))
ci = RigidBodyConstructionInfo(0, ms, cs_ground)
rb_ground = RigidBody(ci, bodyID=1)
del ms, ci
# Create a Rigid body for the dynamic (ie mass > 0) Ball.
ms = DefaultMotionState(Transform(q0, Vec3(0, 5, 0)))
inertia = cs_ball.calculateLocalInertia(1)
ci = RigidBodyConstructionInfo(1, ms, cs_ball, inertia)
rb_ball = RigidBody(ci, bodyID=2)
del ms, inertia, ci
# Ensure that Bullet never deactivates the objects.
rb_ground.forceActivationState(4)
rb_ball.forceActivationState(4)
# Add both bodies to the simulation.
sim.addRigidBody(rb_ground)
sim.addRigidBody(rb_ball)
# Sanity check: the ball must be at position y=5
pos = rb_ball.getMotionState().getWorldTransform().getOrigin()
pos = pos.topy()
assert pos[1] == 5
# Step the simulation long enough for the ball to fall down and
# come to rest on the plane.
for ii in range(10):
sim.stepSimulation(1, 100)
# Verify that the y-position of the ball is such that the ball
# rests on the plane.
pos = rb_ball.getMotionState().getWorldTransform().getOrigin()
return pos.topy()
def getRB(pos=Vec3(0, 0, 0), cshape=SphereShape(1), bodyID=0):
"""
Return a Rigid Body plus auxiliary information (do *not* delete; see
note below).
.. note:: Do not delete the tuple until the end of the test
because it may lead to memory access violations. The reason is that a
rigid body requires several indepenent structures that need to remain
in memory.
"""
t = Transform(Quaternion(0, 0, 0, 1), pos)
ms = DefaultMotionState(t)
mass = 1
# Build construction info and instantiate the rigid body.
ci = RigidBodyConstructionInfo(mass, ms, cshape)
rb = RigidBody(ci, bodyID)
# Ensure the body remains activated.
rb.forceActivationState(4)
return rb
