Reactive force in the event of a collision

Autonomous Machines Isaac Isaac Gym
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#1

Hi all,

when my object which is just a flat square collides with the ground, a weird reactive force occurs (see test.mkv (1.2 MB)). Since the object’s mass is set to 500kg, this doesnt seem to be realistic. Which parameter value should be adjusted in this case? Below you can also see the current simulation parameter values.

sim_params.substeps = 1
if args.physics_engine == gymapi.SIM_PHYSX:
sim_params.physx.solver_type = 5
sim_params.physx.num_position_iterations = 1
sim_params.physx.num_velocity_iterations = 1
sim_params.physx.rest_offset = 0.0
sim_params.physx.contact_offset = 0.1
sim_params.physx.friction_offset_threshold = 0.1
sim_params.physx.friction_correlation_distance = 0.05
sim_params.physx.num_threads = args.num_threads
sim_params.physx.use_gpu = args.use_gpu

#2

Hi @hosei2,

I think it’s because of the solver parameters you share. PhysX has only 2 solvers available and TGS,

sim_params.physx.solver_type = 1

is recommended. Usually it’s better to use 2 or more substeps and also a number of position iterations should be at least 4:

sim_params.physx.num_position_iterations = 1