newton.solvers.XPBDSolver#

class newton.solvers.XPBDSolver(model, iterations=2, soft_body_relaxation=0.9, soft_contact_relaxation=0.9, joint_linear_relaxation=0.7, joint_angular_relaxation=0.4, joint_linear_compliance=0.0, joint_angular_compliance=0.0, rigid_contact_relaxation=0.8, rigid_contact_con_weighting=True, angular_damping=0.0, enable_restitution=False)[source]#

Bases: SolverBase

An implicit integrator using eXtended Position-Based Dynamics (XPBD) for rigid and soft body simulation.

References

  • Miles Macklin, Matthias Müller, and Nuttapong Chentanez. 2016. XPBD: position-based simulation of compliant constrained dynamics. In Proceedings of the 9th International Conference on Motion in Games (MIG ‘16). Association for Computing Machinery, New York, NY, USA, 49-54. https://doi.org/10.1145/2994258.2994272

  • Matthias Müller, Miles Macklin, Nuttapong Chentanez, Stefan Jeschke, and Tae-Yong Kim. 2020. Detailed rigid body simulation with extended position based dynamics. In Proceedings of the ACM SIGGRAPH/Eurographics Symposium on Computer Animation (SCA ‘20). Eurographics Association, Goslar, DEU, Article 10, 1-12. https://doi.org/10.1111/cgf.14105

After constructing Model, State, and Control (optional) objects, this time-integrator may be used to advance the simulation state forward in time.

Example

solver = newton.solvers.XPBDSolver(model)

# simulation loop
for i in range(100):
    solver.step(state_in, state_out, control, contacts, dt)
    state_in, state_out = state_out, state_in
__init__(model, iterations=2, soft_body_relaxation=0.9, soft_contact_relaxation=0.9, joint_linear_relaxation=0.7, joint_angular_relaxation=0.4, joint_linear_compliance=0.0, joint_angular_compliance=0.0, rigid_contact_relaxation=0.8, rigid_contact_con_weighting=True, angular_damping=0.0, enable_restitution=False)#
step(state_in, state_out, control, contacts, dt)#