diff --git a/Sofa/Component/SolidMechanics/FEM/Elastic/src/sofa/component/solidmechanics/fem/elastic/FastTetrahedralCorotationalForceField.inl b/Sofa/Component/SolidMechanics/FEM/Elastic/src/sofa/component/solidmechanics/fem/elastic/FastTetrahedralCorotationalForceField.inl index 759cf36ae87..5d0ba93ddb6 100644 --- a/Sofa/Component/SolidMechanics/FEM/Elastic/src/sofa/component/solidmechanics/fem/elastic/FastTetrahedralCorotationalForceField.inl +++ b/Sofa/Component/SolidMechanics/FEM/Elastic/src/sofa/component/solidmechanics/fem/elastic/FastTetrahedralCorotationalForceField.inl @@ -556,7 +556,7 @@ void FastTetrahedralCorotationalForceField::buildStiffnessMatrix( for(sofa::Size i=0; i < nbEdges; ++i ) { const auto& edge = edges[i]; - dfdx(3 * edge[0], 3 * edge[1]) += -edgeDfDx[i]; + dfdx(3 * edge[0], 3 * edge[1]) += -edgeDfDx[i].transposed(); dfdx(3 * edge[1], 3 * edge[0]) += -edgeDfDx[i]; } }