From a816ca6dd53f92658d576c3b587729a33d5b8d0a Mon Sep 17 00:00:00 2001
From: Yuval Tassa <tassa@google.com>
Date: Thu, 6 Mar 2025 21:14:38 -0800
Subject: [PATCH] Use `qLDiagInv` instead of `qLD` in `engine_vis_interact.c`

PiperOrigin-RevId: 734399015
Change-Id: I97c80a8b25dbd40e86560c328cc786a0bed6a2d1
---
 src/engine/engine_vis_interact.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/src/engine/engine_vis_interact.c b/src/engine/engine_vis_interact.c
index 2e400e56..4ea29d55 100644
--- a/src/engine/engine_vis_interact.c
+++ b/src/engine/engine_vis_interact.c
@@ -556,8 +556,7 @@ void mjv_initPerturb(const mjModel* m, mjData* d, const mjvScene* scn, mjvPertur
 
   // compute average spatial inertia at selection point
   for (int i=0; i < nv; i++) {
-    int diag = d->M_rowadr[i] + d->M_rownnz[i] - 1;
-    sqrtInvD[i] = 1 / mju_sqrt(d->qLD[diag]);
+    sqrtInvD[i] = mju_sqrt(d->qLDiagInv[i]);
   }
   mj_jac(m, d, jac, NULL, selpos, sel);
   mj_solveM2(m, d, jacM2, jac, sqrtInvD, 3);