From e1dc69f56d5725415b2945ecdf72faecd098b67c Mon Sep 17 00:00:00 2001
From: 0penBrain <48731257+0penBrain@users.noreply.github.com>
Date: Tue, 21 Sep 2021 19:10:46 +0200
Subject: [PATCH] [Core] Rotation : improve gimbal lock handling

 Tolerance copied from OCC "gp_Quaternion.cxx"
---
 src/Base/Rotation.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/Base/Rotation.cpp b/src/Base/Rotation.cpp
index 118a7c6563..646731561d 100644
--- a/src/Base/Rotation.cpp
+++ b/src/Base/Rotation.cpp
@@ -673,13 +673,13 @@ void Rotation::getYawPitchRoll(double& y, double& p, double& r) const
     double qd2 = 2.0*(q13-q02);
 
     // handle gimbal lock
-    if (fabs(qd2-1.0) <= DBL_EPSILON) {
+    if (fabs(qd2-1.0) <= 16 * DBL_EPSILON) { // Tolerance copied from OCC "gp_Quaternion.cxx"
         // north pole
         y = 0.0;
         p = D_PI/2.0;
         r = 2.0 * atan2(quat[0],quat[3]);
     }
-    else if (fabs(qd2+1.0) <= DBL_EPSILON) {
+    else if (fabs(qd2+1.0) <= 16 * DBL_EPSILON) { // Tolerance copied from OCC "gp_Quaternion.cxx"
         // south pole
         y = 0.0;
         p = -D_PI/2.0;