add corotated model to lagrangian forces

src/BulletSoftBody/btSoftBodyHelpers.cpp

@@ -1221,6 +1221,7 @@ if(face&&face[0])
 			}
 		}
 	}
+    psb->initializeDmInverse();
 	printf("Nodes:  %u\r\n", psb->m_nodes.size());
 	printf("Links:  %u\r\n", psb->m_links.size());
 	printf("Faces:  %u\r\n", psb->m_faces.size());