# how to reset geometry with on actors with trame

**URL:** <https://discourse.vtk.org/t/how-to-reset-geometry-with-on-actors-with-trame/16074>\
**Category:** Development\
**Created:** [October 1, 2025, 1:00pm UTC](https://discourse.vtk.org/t/how-to-reset-geometry-with-on-actors-with-trame/16074 "2025-10-01T13:00:50Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![jtristanod3d](https://discourse.vtk.org/user_avatar/discourse.vtk.org/jtristanod3d/32/10299_2.png) [@jtristanod3d](https://discourse.vtk.org/u/jtristanod3d)\
**Post date:** [October 1, 2025, 1:00pm UTC](https://discourse.vtk.org/t/how-to-reset-geometry-with-on-actors-with-trame/16074/1 "2025-10-01T13:00:50Z")

</div>

I’m iterating through pvd time steps where the geometry changes drastically. I need o update the actors accordingly. If I remove the actor and add new actors, I get VTK pipeline errors

```auto
vtkDataSetMapper (0x3d09490) has 0 connections but is not optional.
JS Error => 2025-10-01 08:30:10.800 ( 25.825s) [4B5474]vtkDemandDrivenPipeline:677 ERR| vtkCompositeDataPipeline (0x1886fa0): Input port 0 of algorithm vtkDataSetMapper (0x1869fb0) has 0 connections but is not optional.

```

If I do the following, the colors update from the new dataset – strangley, since the point data sizes are different but the geometry doesnt update

```auto

    @change("selected_pvd_point")
    def _on_selected_pvd_point(self, selected_pvd_point, **_):
        if self.first_render:
            print("First render, ignoring selected_pvd_point change")
            return
        print("Selected PVD point changed:", selected_pvd_point)
        self.pvd_reader.set_active_time_value(selected_pvd_point)
        dataset = self.pvd_reader.read()   
        flattened = dataset.flatten()
        block_ids = [i for i in self.block_id_to_mesh.keys()]
        print(f"Updating {len(flattened)} blocks")
        for mesh, block_id in zip(flattened, block_ids):
            self.block_id_to_mesh[block_id] = mesh
            self._block_id_to_actor[block_id].mapper.SetInputData(mesh)
            mesh.cell_data.VTKObject.Modified()
        self.update_actor_scalars(self.server.state.visible_blocks, self.server.state.selected_loadcase, self.get_result_field_id())
        print("Rendering after PVD point change")
        self.plotter.reset_camera()
        self.plotter.render()
        self.ctx.view.update()
        

```

Any help would be appreciated!

Best Regards

Joe

---

<div class="post-metadata">

**Author:** ![Sebastien\_Jourdain](https://discourse.vtk.org/user_avatar/discourse.vtk.org/sebastien_jourdain/32/100_2.png) [@Sebastien\_Jourdain](https://discourse.vtk.org/u/Sebastien_Jourdain)\
**Post date:** [October 10, 2025, 3:07pm UTC](https://discourse.vtk.org/t/how-to-reset-geometry-with-on-actors-with-trame/16074/2 "2025-10-10T15:07:21Z")

</div>

Can you provide a small example with data that illustrate the problem? If it is related to VTK.wasm, you can create an issue with code+data on [trame-vtklocal](https://github.com/Kitware/trame-vtklocal).