This feature is for viewing existing 3D (VTK) models published in IGW-NET (3D models are available for 3D groundwater models, 3D TP (geologic model) and 3D interpolation model - see 'Publish to..' in MAGNET 3D Surface Plot interface). You may not be able to add new data/layer to the current view using this interface.
Select 3D Model File
Click the button next to 'Uploaded File' to populate the drop-down menu with existing 3D model files published under your account. The selected file will be displayed in the greyed out text area underneath the drop-down menu
Apply (Launch 3D View)
Once the proper 3D model file is selected, click 'Apply' to show the 3D model in a new VTK 3D interface.