From 3283fb86550e363fcd249c1b34712f0c98defabc Mon Sep 17 00:00:00 2001
From: Kyle Bayes <kylebayes@google.com>
Date: Mon, 21 Jul 2025 05:10:57 -0700
Subject: [PATCH] Fix sign in cylinder support function.

PiperOrigin-RevId: 785394029
Change-Id: I010edab0ba8734a9b91626669fa309a0ddb346e5
---
 src/engine/engine_collision_convex.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/engine/engine_collision_convex.c b/src/engine/engine_collision_convex.c
index 16b3b05c..438648de 100644
--- a/src/engine/engine_collision_convex.c
+++ b/src/engine/engine_collision_convex.c
@@ -304,7 +304,7 @@ static void mjc_cylinderSupport(mjtNum res[3], mjCCDObj* obj, const mjtNum dir[3
   }
 
   // set result in Z direction
-  tmp[2] = mju_sign(local_dir[2]) * size[1];
+  tmp[2] = local_dir[2] >= 0 ? size[1] : -size[1];
 
   // transform result to global frame
   localToGlobal(res, mat, tmp, pos);