Restrict midpoint integration to unconstrained free bodies in implicitfast

PiperOrigin-RevId: 908750768 Change-Id: I9a45a160ac757cc82bfe54871609956769988369
2026-05-01 08:40:53 -07:00
parent 8287d9d152
commit 910b3336ed
5 changed files with 221 additions and 94 deletions
@@ -8,6 +8,11 @@ Upcoming version (not yet released)
 - Added island support for the :ref:`PGS solver<soAlgorithms>`.
 - Added support for :ref:`elastic2d<body-flexcomp-elastic2d>` for trilinear and quadratic flex
  :ref:`dofs<body-flexcomp-dof>`.
+- :ref:`Midpoint integration<geMidpoint>` is now restricted to the ``implicitfast``
+  :ref:`integrator<geIntegrators>` and is disabled when fluid forces are active
+  (nonzero :ref:`density<option-density>` or :ref:`viscosity<option-viscosity>`).
+  Midpoint integration treats external forces as zero-order-hold constants, which causes
+  energy gain in the presence of contacts and in fluid media.

 Python
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