From a99eabc7b0cdd88f411a210e9287e051b416833c Mon Sep 17 00:00:00 2001
From: epernod <erik.pernod@gmail.com>
Date: Tue, 20 Jan 2026 12:11:56 +0100
Subject: [PATCH 1/6] quick test on current regression

---
 examples/Demos/chainAll.scn | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/examples/Demos/chainAll.scn b/examples/Demos/chainAll.scn
index 58e7cc24ff6..9a93d2b3473 100644
--- a/examples/Demos/chainAll.scn
+++ b/examples/Demos/chainAll.scn
@@ -32,7 +32,7 @@
 
     <Node name="TorusFixed">
         <MeshTopology src="@../loader_torus2_for_collision" />
-        <MechanicalObject src="@../loader_torus2_for_collision" />
+        <MechanicalObject name="tata" src="@../loader_torus2_for_collision" />
         <TriangleCollisionModel moving="0" simulated="0" />
         <LineCollisionModel moving="0" simulated="0" />
         <PointCollisionModel moving="0" simulated="0" />
@@ -44,7 +44,7 @@
         <EulerImplicitSolver  rayleighStiffness="0.1" rayleighMass="0.1"/>
         <CGLinearSolver iterations="100" threshold="1e-08" tolerance="1e-05" />
         <MeshTopology src="@../loader_torus_low_res" />
-        <MechanicalObject dx="7.6871" dy="0.0000" dz="0.9632" rx="10.0000" ry="-15.0000" rz="0.0000" src="@../loader_torus_low_res" />
+        <MechanicalObject name="toto" dx="7.6871" dy="0.0000" dz="0.9632" rx="10.0000" ry="-15.0000" rz="0.0000" src="@../loader_torus_low_res" />
         <UniformMass totalMass="5" />
         <TetrahedronFEMForceField computeGlobalMatrix="false" method="polar" name="FEM" poissonRatio="0.3" youngModulus="5000" />
         <Node name="Visu">

From bd556be33bdec067eb36c71e08cb14736326d516 Mon Sep 17 00:00:00 2001
From: erik pernod <erik.pernod@gmail.com>
Date: Tue, 20 Jan 2026 17:59:10 +0100
Subject: [PATCH 2/6] messing up the masses

---
 examples/Demos/chainAll.scn | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/examples/Demos/chainAll.scn b/examples/Demos/chainAll.scn
index 9a93d2b3473..e2d57483d9c 100644
--- a/examples/Demos/chainAll.scn
+++ b/examples/Demos/chainAll.scn
@@ -45,7 +45,7 @@
         <CGLinearSolver iterations="100" threshold="1e-08" tolerance="1e-05" />
         <MeshTopology src="@../loader_torus_low_res" />
         <MechanicalObject name="toto" dx="7.6871" dy="0.0000" dz="0.9632" rx="10.0000" ry="-15.0000" rz="0.0000" src="@../loader_torus_low_res" />
-        <UniformMass totalMass="5" />
+        <UniformMass totalMass="15" />
         <TetrahedronFEMForceField computeGlobalMatrix="false" method="polar" name="FEM" poissonRatio="0.3" youngModulus="5000" />
         <Node name="Visu">
             <OglModel color="1.000 0.000 0.000" dx="7.6871" dy="0.0000" dz="0.9632" src="@../../loader_torus" name="Visual" rx="10.0000" ry="-15.0000" rz="0.0000" />
@@ -65,7 +65,7 @@
         <CGLinearSolver iterations="100" threshold="1e-08" tolerance="1e-05"/>
         <MeshTopology src="@../loader_torus2_low_res" />
         <MechanicalObject dx="10.0309" dy="0.0000" dz="2.1145" rx="15.0000" ry="-25.0000" rz="0.0000" src="@../loader_torus2_low_res" />
-        <UniformMass totalMass="5" />
+        <UniformMass totalMass="15" />
         <MeshSpringForceField name="Springs" tetrasDamping="4" tetrasStiffness="1000" />
         <Node name="Visu">
             <OglModel color="0.000 1.000 0.000" dx="10.0309" dy="0.0000" dz="2.1145" src="@../../loader_torus2" name="Visual" rx="15.0000" ry="-25.0000" rz="0.0000" />
@@ -84,7 +84,7 @@
         <EulerImplicitSolver rayleighStiffness="0.1" rayleighMass="0.1"/>
         <CGLinearSolver iterations="100" threshold="1e-08" tolerance="1e-05"/>
         <MechanicalObject dx="12.3521" dy="0.0000" dz="3.2783" rx="20.0000" ry="-30.0000" rz="0.0000" />
-        <UniformMass totalMass="5" />
+        <UniformMass totalMass="15" />
         <RegularGridTopology nx="6" ny="2" nz="5" xmax="2.5" xmin="-2.5" ymax="0.5" ymin="-0.5" zmax="2" zmin="-2" />
         <RegularGridSpringForceField damping="2" name="Springs" stiffness="200" />
         <Node name="Visu">
@@ -104,7 +104,7 @@
         <EulerImplicitSolver rayleighStiffness="0.01" rayleighMass="0.01"/>
         <CGLinearSolver iterations="100" threshold="1e-08" tolerance="1e-05"/>
         <MechanicalObject dx="14.4679" dy="0.0000" dz="4.7604" rx="25.0000" ry="-35.0000" rz="0.0000" template="Rigid3" />
-        <UniformMass totalMass="10"/>
+        <UniformMass totalMass="1"/>
         <Node name="Visu">
             <OglModel color="0.500 0.500 0.500" src="@../../loader_torus2" name="Visual" />
             <RigidMapping input="@.." output="@Visual" />
@@ -123,7 +123,7 @@
         <CGLinearSolver iterations="100" threshold="1e-08" tolerance="1e-05"/>
         <MeshTopology src="@../loader_torus_low_res" />
         <MechanicalObject dx="20.7850" dy="0.1285" dz="15.4381" rx="-36.1968" ry="38.9599" rz="6.3146" src="@../loader_torus_low_res" />
-        <UniformMass totalMass="5" />
+        <UniformMass totalMass="15" />
         <TetrahedronFEMForceField computeGlobalMatrix="false" method="polar" name="FEM" poissonRatio="0.3" youngModulus="5000" />
         <Node name="Visu">
             <OglModel color="1.000 0.000 0.000" dx="20.7850" dy="0.1285" dz="15.4381" src="@../../loader_torus" name="Visual" rx="-36.1968" ry="38.9599" rz="6.3146" />
@@ -143,7 +143,7 @@
         <CGLinearSolver iterations="100" threshold="1e-08" tolerance="1e-05"/>
         <MeshTopology src="@../loader_torus2_low_res" />
         <MechanicalObject dx="22.1025" dy="-0.1037" dz="13.4780" rx="-26.3682" ry="62.5274" rz="-0.8890" src="@../loader_torus2_low_res" />
-        <UniformMass totalMass="5" />
+        <UniformMass totalMass="15" />
         <TetrahedronFEMForceField computeGlobalMatrix="false" method="polar" name="FEM" poissonRatio="0.3" youngModulus="5000" />
         <Node name="Visu">
             <OglModel color="1.000 0.000 0.000" dx="22.1025" dy="-0.1037" dz="13.4780" src="@../../loader_torus2" name="Visual" rx="-26.3682" ry="62.5274" rz="-0.8890" />
@@ -163,7 +163,7 @@
         <CGLinearSolver iterations="100" threshold="1e-08" tolerance="1e-05"/>
         <MeshTopology src="@../loader_torus_low_res" />
         <MechanicalObject dx="2.5428" dy="0.0000" dz="0.0195" rx="-0.0000" ry="-5.0000" rz="0.0000" src="@../loader_torus_low_res" />
-        <UniformMass totalMass="5" />
+        <UniformMass totalMass="15" />
         <TetrahedronFEMForceField computeGlobalMatrix="false" method="polar" name="FEM" poissonRatio="0.3" youngModulus="5000" />
         <Node name="Visu">
             <OglModel color="1.000 0.000 0.000" dx="2.5428" dy="0.0000" dz="0.0195" src="@../../loader_torus" name="Visual" rx="-0.0000" ry="-5.0000" rz="0.0000" />
@@ -183,7 +183,7 @@
         <CGLinearSolver iterations="100" threshold="1e-08" tolerance="1e-05"/>
         <MeshTopology src="@../loader_torus2_low_res" />
         <MechanicalObject dx="5.1472" dy="0.0000" dz="0.3725" rx="5.0000" ry="-10.0000" rz="0.0000" src="@../loader_torus2_low_res" />
-        <UniformMass totalMass="5" />
+        <UniformMass totalMass="15" />
         <TetrahedronFEMForceField computeGlobalMatrix="false" method="polar" name="FEM" poissonRatio="0.3" youngModulus="5000" />
         <Node name="Visu">
             <OglModel color="1.000 0.000 0.000" dx="5.1472" dy="0.0000" dz="0.3725" src="@../../loader_torus2" name="Visual" rx="5.0000" ry="-10.0000" rz="0.0000" />

From 6f956a1d93f7f98abdd1a032a249a6642671fc03 Mon Sep 17 00:00:00 2001
From: epernod <erik.pernod@gmail.com>
Date: Tue, 20 Jan 2026 19:39:11 +0100
Subject: [PATCH 3/6] boom!

---
 .../Playback/src/sofa/component/playback/CompareState.cpp   | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/Sofa/Component/Playback/src/sofa/component/playback/CompareState.cpp b/Sofa/Component/Playback/src/sofa/component/playback/CompareState.cpp
index 989ea02d5bb..59937d80d3e 100644
--- a/Sofa/Component/Playback/src/sofa/component/playback/CompareState.cpp
+++ b/Sofa/Component/Playback/src/sofa/component/playback/CompareState.cpp
@@ -171,6 +171,12 @@ void CompareState::processCompareState()
         }
     }
 
+    if (validLines.empty()) // No references found, we need to notify that this is not a correct result
+    {
+        totalError_X = std::numeric_limits<double>::max();
+        totalError_V = std::numeric_limits<double>::max();
+    }
+
     msg_info() << "totalError_X = " << totalError_X << ", totalError_V = " << totalError_V;
 }
 

From 0189a7b0d49ca5367b90c070d49a21d15cbae37d Mon Sep 17 00:00:00 2001
From: erik pernod <erik.pernod@gmail.com>
Date: Thu, 29 Jan 2026 15:09:36 +0100
Subject: [PATCH 4/6] Other test

---
 examples/Component/Mass/DiagonalMass.scn | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/examples/Component/Mass/DiagonalMass.scn b/examples/Component/Mass/DiagonalMass.scn
index f83e61ebcb5..332024c098e 100644
--- a/examples/Component/Mass/DiagonalMass.scn
+++ b/examples/Component/Mass/DiagonalMass.scn
@@ -32,7 +32,7 @@
         <!-- Container for the tetrahedra-->
         <TetrahedronSetTopologyContainer name="TetraTopo" src="@../loader" />
         <TetrahedronSetGeometryAlgorithms name="GeomAlgo" />
-        <DiagonalMass totalMass="60" name="diagonalMass" />
+        <DiagonalMass totalMass="100" name="diagonalMass" />
         <TetrahedralCorotationalFEMForceField template="Vec3" name="FEM" method="large" poissonRatio="0.45" youngModulus="5000" />
         <FixedProjectiveConstraint name="FixedProjectiveConstraint" indices="3 39 64" />
         

From 3844f94b45e4f967bdacf63c026a3daa7b26bff9 Mon Sep 17 00:00:00 2001
From: erik pernod <erik.pernod@gmail.com>
Date: Fri, 30 Jan 2026 17:38:18 +0100
Subject: [PATCH 5/6] revert

---
 examples/Component/Mass/DiagonalMass.scn | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/examples/Component/Mass/DiagonalMass.scn b/examples/Component/Mass/DiagonalMass.scn
index 332024c098e..f83e61ebcb5 100644
--- a/examples/Component/Mass/DiagonalMass.scn
+++ b/examples/Component/Mass/DiagonalMass.scn
@@ -32,7 +32,7 @@
         <!-- Container for the tetrahedra-->
         <TetrahedronSetTopologyContainer name="TetraTopo" src="@../loader" />
         <TetrahedronSetGeometryAlgorithms name="GeomAlgo" />
-        <DiagonalMass totalMass="100" name="diagonalMass" />
+        <DiagonalMass totalMass="60" name="diagonalMass" />
         <TetrahedralCorotationalFEMForceField template="Vec3" name="FEM" method="large" poissonRatio="0.45" youngModulus="5000" />
         <FixedProjectiveConstraint name="FixedProjectiveConstraint" indices="3 39 64" />
         

From 8b608de2283ea3f8f8c0b1e30b50829f5efe1c10 Mon Sep 17 00:00:00 2001
From: erik pernod <erik.pernod@gmail.com>
Date: Fri, 30 Jan 2026 17:40:26 +0100
Subject: [PATCH 6/6] revert changes

---
 examples/Demos/chainAll.scn | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/examples/Demos/chainAll.scn b/examples/Demos/chainAll.scn
index e2d57483d9c..58e7cc24ff6 100644
--- a/examples/Demos/chainAll.scn
+++ b/examples/Demos/chainAll.scn
@@ -32,7 +32,7 @@
 
     <Node name="TorusFixed">
         <MeshTopology src="@../loader_torus2_for_collision" />
-        <MechanicalObject name="tata" src="@../loader_torus2_for_collision" />
+        <MechanicalObject src="@../loader_torus2_for_collision" />
         <TriangleCollisionModel moving="0" simulated="0" />
         <LineCollisionModel moving="0" simulated="0" />
         <PointCollisionModel moving="0" simulated="0" />
@@ -44,8 +44,8 @@
         <EulerImplicitSolver  rayleighStiffness="0.1" rayleighMass="0.1"/>
         <CGLinearSolver iterations="100" threshold="1e-08" tolerance="1e-05" />
         <MeshTopology src="@../loader_torus_low_res" />
-        <MechanicalObject name="toto" dx="7.6871" dy="0.0000" dz="0.9632" rx="10.0000" ry="-15.0000" rz="0.0000" src="@../loader_torus_low_res" />
-        <UniformMass totalMass="15" />
+        <MechanicalObject dx="7.6871" dy="0.0000" dz="0.9632" rx="10.0000" ry="-15.0000" rz="0.0000" src="@../loader_torus_low_res" />
+        <UniformMass totalMass="5" />
         <TetrahedronFEMForceField computeGlobalMatrix="false" method="polar" name="FEM" poissonRatio="0.3" youngModulus="5000" />
         <Node name="Visu">
             <OglModel color="1.000 0.000 0.000" dx="7.6871" dy="0.0000" dz="0.9632" src="@../../loader_torus" name="Visual" rx="10.0000" ry="-15.0000" rz="0.0000" />
@@ -65,7 +65,7 @@
         <CGLinearSolver iterations="100" threshold="1e-08" tolerance="1e-05"/>
         <MeshTopology src="@../loader_torus2_low_res" />
         <MechanicalObject dx="10.0309" dy="0.0000" dz="2.1145" rx="15.0000" ry="-25.0000" rz="0.0000" src="@../loader_torus2_low_res" />
-        <UniformMass totalMass="15" />
+        <UniformMass totalMass="5" />
         <MeshSpringForceField name="Springs" tetrasDamping="4" tetrasStiffness="1000" />
         <Node name="Visu">
             <OglModel color="0.000 1.000 0.000" dx="10.0309" dy="0.0000" dz="2.1145" src="@../../loader_torus2" name="Visual" rx="15.0000" ry="-25.0000" rz="0.0000" />
@@ -84,7 +84,7 @@
         <EulerImplicitSolver rayleighStiffness="0.1" rayleighMass="0.1"/>
         <CGLinearSolver iterations="100" threshold="1e-08" tolerance="1e-05"/>
         <MechanicalObject dx="12.3521" dy="0.0000" dz="3.2783" rx="20.0000" ry="-30.0000" rz="0.0000" />
-        <UniformMass totalMass="15" />
+        <UniformMass totalMass="5" />
         <RegularGridTopology nx="6" ny="2" nz="5" xmax="2.5" xmin="-2.5" ymax="0.5" ymin="-0.5" zmax="2" zmin="-2" />
         <RegularGridSpringForceField damping="2" name="Springs" stiffness="200" />
         <Node name="Visu">
@@ -104,7 +104,7 @@
         <EulerImplicitSolver rayleighStiffness="0.01" rayleighMass="0.01"/>
         <CGLinearSolver iterations="100" threshold="1e-08" tolerance="1e-05"/>
         <MechanicalObject dx="14.4679" dy="0.0000" dz="4.7604" rx="25.0000" ry="-35.0000" rz="0.0000" template="Rigid3" />
-        <UniformMass totalMass="1"/>
+        <UniformMass totalMass="10"/>
         <Node name="Visu">
             <OglModel color="0.500 0.500 0.500" src="@../../loader_torus2" name="Visual" />
             <RigidMapping input="@.." output="@Visual" />
@@ -123,7 +123,7 @@
         <CGLinearSolver iterations="100" threshold="1e-08" tolerance="1e-05"/>
         <MeshTopology src="@../loader_torus_low_res" />
         <MechanicalObject dx="20.7850" dy="0.1285" dz="15.4381" rx="-36.1968" ry="38.9599" rz="6.3146" src="@../loader_torus_low_res" />
-        <UniformMass totalMass="15" />
+        <UniformMass totalMass="5" />
         <TetrahedronFEMForceField computeGlobalMatrix="false" method="polar" name="FEM" poissonRatio="0.3" youngModulus="5000" />
         <Node name="Visu">
             <OglModel color="1.000 0.000 0.000" dx="20.7850" dy="0.1285" dz="15.4381" src="@../../loader_torus" name="Visual" rx="-36.1968" ry="38.9599" rz="6.3146" />
@@ -143,7 +143,7 @@
         <CGLinearSolver iterations="100" threshold="1e-08" tolerance="1e-05"/>
         <MeshTopology src="@../loader_torus2_low_res" />
         <MechanicalObject dx="22.1025" dy="-0.1037" dz="13.4780" rx="-26.3682" ry="62.5274" rz="-0.8890" src="@../loader_torus2_low_res" />
-        <UniformMass totalMass="15" />
+        <UniformMass totalMass="5" />
         <TetrahedronFEMForceField computeGlobalMatrix="false" method="polar" name="FEM" poissonRatio="0.3" youngModulus="5000" />
         <Node name="Visu">
             <OglModel color="1.000 0.000 0.000" dx="22.1025" dy="-0.1037" dz="13.4780" src="@../../loader_torus2" name="Visual" rx="-26.3682" ry="62.5274" rz="-0.8890" />
@@ -163,7 +163,7 @@
         <CGLinearSolver iterations="100" threshold="1e-08" tolerance="1e-05"/>
         <MeshTopology src="@../loader_torus_low_res" />
         <MechanicalObject dx="2.5428" dy="0.0000" dz="0.0195" rx="-0.0000" ry="-5.0000" rz="0.0000" src="@../loader_torus_low_res" />
-        <UniformMass totalMass="15" />
+        <UniformMass totalMass="5" />
         <TetrahedronFEMForceField computeGlobalMatrix="false" method="polar" name="FEM" poissonRatio="0.3" youngModulus="5000" />
         <Node name="Visu">
             <OglModel color="1.000 0.000 0.000" dx="2.5428" dy="0.0000" dz="0.0195" src="@../../loader_torus" name="Visual" rx="-0.0000" ry="-5.0000" rz="0.0000" />
@@ -183,7 +183,7 @@
         <CGLinearSolver iterations="100" threshold="1e-08" tolerance="1e-05"/>
         <MeshTopology src="@../loader_torus2_low_res" />
         <MechanicalObject dx="5.1472" dy="0.0000" dz="0.3725" rx="5.0000" ry="-10.0000" rz="0.0000" src="@../loader_torus2_low_res" />
-        <UniformMass totalMass="15" />
+        <UniformMass totalMass="5" />
         <TetrahedronFEMForceField computeGlobalMatrix="false" method="polar" name="FEM" poissonRatio="0.3" youngModulus="5000" />
         <Node name="Visu">
             <OglModel color="1.000 0.000 0.000" dx="5.1472" dy="0.0000" dz="0.3725" src="@../../loader_torus2" name="Visual" rx="5.0000" ry="-10.0000" rz="0.0000" />