compute BB over mesh instead of SceneGraph

ObjectTypes/MeshObject/MeshObjectT_impl.hh

@@ -642,12 +642,18 @@
    */
   template < class MeshT  >
   void MeshObject< MeshT >::boundingBox( ACG::Vec3d& _bbMin , ACG::Vec3d& _bbMax ) {
-    if ( meshNode_ ) {
-      _bbMin = ACG::Vec3d(FLT_MAX, FLT_MAX, FLT_MAX);
-      _bbMax = ACG::Vec3d(-FLT_MAX, -FLT_MAX, -FLT_MAX);
-      meshNode_->boundingBox(_bbMin,_bbMax);
+    
+    if ( mesh_ ) {
+      _bbMin = mesh_->point(mesh_->vertex_handle(0));
+      _bbMax = mesh_->point(mesh_->vertex_handle(0));
+      for ( auto v_it : mesh_->vertices()) {
+        const ACG::Vec3d p = mesh_->point(v_it);
+        _bbMin.minimize(p);
+        _bbMax.maximize(p);
+      }
     } else {
-      std::cerr << "Error: Bounding box computation via Scenegraph not available without gui" << std::endl;
+      // This is basicly impossible, but just in case
+      std::cerr << "Error: No Mesh found" << std::endl;
     }
   }