From 64a2345c07e2748962f5d35b2c0a1128287ff52e Mon Sep 17 00:00:00 2001
From: Sam Haves <shaves@google.com>
Date: Fri, 9 Jan 2026 10:59:01 -0800
Subject: [PATCH] Fix usethread check to enable multithreaded mesh compilation.

PiperOrigin-RevId: 854260636
Change-Id: I18d1f47a1ef7f8abcce14e0351b9523fbbac8be6
---
 src/user/user_model.cc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/user/user_model.cc b/src/user/user_model.cc
index dc1fa88b..624b77c2 100644
--- a/src/user/user_model.cc
+++ b/src/user/user_model.cc
@@ -4748,7 +4748,7 @@ void mjCModel::TryCompile(mjModel*& m, mjData*& d, const mjVFS* vfs) {
   SetNuser();
 
   // compile meshes (needed for geom compilation)
-  if (!compiler.usethread && meshes_.size() > 1) {
+  if (compiler.usethread && meshes_.size() > 1) {
     // multi-threaded mesh compile
     CompileMeshes(vfs);
   } else {