Merge pull request #921 from KratosMultiphysics/hotfix-mpm-grid-nodes

Grid mdpa should contain only grid nodes

Author: lauramoremar

kratos.gid/apps/MPM/write/write.tcl

@@ -38,7 +38,7 @@ proc MPM::write::writeModelPartEvent { } {
     write::WriteString "End Properties"
 
     # Nodal coordinates
-    write::writeNodalCoordinates
+    write::writeNodalCoordinatesOnGroups [MPM::write::GetPartsGroups grid]
 
     # Grid element connectivities
     writeGridConnectivities