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# basic simulation showing sphere falling ball gravity,
# bouncing against another sphere representing the support
# DATA COMPONENTS
# add 2 particles to the simulation
# they the default material (utils.defaultMat)
O.bodies.append(
[
# fixed: particle's position in space will not change (support)
sphere(center=(0, 0, 0), radius=.5, fixed=True),
# this particles is free, subject to dynamics
sphere((0, 0, 2), .5)
]
)
# FUNCTIONAL COMPONENTS
# simulation loop -- see presentation for the explanation
O.engines = [
ForceResetter(),
InsertionSortCollider([Bo1_Sphere_Aabb()]),
InteractionLoop(
[Ig2_Sphere_Sphere_ScGeom()], # collision geometry
[Ip2_FrictMat_FrictMat_FrictPhys()], # collision "physics"
[Law2_ScGeom_FrictPhys_CundallStrack()] # contact law -- apply forces
),
# Apply gravity force to particles. damping: numerical dissipation of energy.
NewtonIntegrator(gravity=(0, 0, -9.81), damping=0.1)
]
# set timestep to a fraction of the critical timestep
# the fraction is very small, so that the simulation is not too fast
# and the motion can be observed
O.dt = .5e-4 * PWaveTimeStep()
# save the simulation, so that it can be reloaded later, for experimentation
O.saveTmp()
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