From fbcd96d03f7a5384ee6f88d1602ab88a64082065 Mon Sep 17 00:00:00 2001
From: Nimrod Gileadi <nimrod@google.com>
Date: Tue, 12 Sep 2023 07:13:25 -0700
Subject: [PATCH] BEGIN_PUBLIC Zero all of act_dot when there are custom
 actuator dynamics, but no callback. END_PUBLIC

PiperOrigin-RevId: 564712105
Change-Id: I107481727a42eb2577d62e29ac4e1496c56bb634
---
 src/engine/engine_forward.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/engine/engine_forward.c b/src/engine/engine_forward.c
index 5a38c92e..e406ed7a 100644
--- a/src/engine/engine_forward.c
+++ b/src/engine/engine_forward.c
@@ -264,7 +264,7 @@ void mj_fwdActuation(const mjModel* m, mjData* d) {
           mjcb_act_dyn(m, d, i);
         }
       } else {
-        d->act_dot[j] = 0;
+        mju_zero(d->act_dot + j, m->actuator_actnum[i]);
       }
     }
   }