From 27bb74d7df3aa24032a6584291632f8f3648c972 Mon Sep 17 00:00:00 2001
From: Baruch Tabanpour <btaba@google.com>
Date: Tue, 15 Jul 2025 10:21:20 -0700
Subject: [PATCH] Set MJX minimum friction value to mjMINMU.

PiperOrigin-RevId: 783381620
Change-Id: I353a4fa39956ecb0ed0e1b2bbcaff651e8c68606
---
 mjx/mujoco/mjx/_src/collision_driver.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/mjx/mujoco/mjx/_src/collision_driver.py b/mjx/mujoco/mjx/_src/collision_driver.py
index 1ab14cd0..2f45bca8 100644
--- a/mjx/mujoco/mjx/_src/collision_driver.py
+++ b/mjx/mujoco/mjx/_src/collision_driver.py
@@ -271,7 +271,7 @@ def _contact_groups(m: Model, d: Data) -> Dict[FunctionKey, Contact]:
       # pair contacts get their params from m.pair_* fields
       params.append((
           m.pair_margin[ip] - m.pair_gap[ip],
-          m.pair_friction[ip],
+          jp.clip(m.pair_friction[ip], a_min=eps),
           m.pair_solref[ip],
           m.pair_solreffriction[ip],
           m.pair_solimp[ip],
@@ -321,7 +321,7 @@ def _contact_groups(m: Model, d: Data) -> Dict[FunctionKey, Contact]:
         pos=None,
         frame=None,
         includemargin=includemargin,
-        friction=jp.maximum(friction, mujoco.mjMINMU),
+        friction=friction,
         solref=solref,
         solreffriction=solreffriction,
         solimp=solimp,