This setting defines the behaviour of the parameter widget on the right of the viewer window. There are two modes of interaction with the parameters:
Each change to a parameter results in an immediate update of the model according the new value of the parameter.
A parameter change does not trigger a change in the model immediately. Users can instead set the values of one or several parameters without updating the model. The parameter widget enters in the validation mode:
The changed parameters turn blue, indicated that their value has changed from the current model state.
Two buttons Apply and Cancel are added to the bottom of the widget. Clicking on Apply will send a request to update the model with all the changed parameter values. Clicking on Cancel will forget about the changes and restore the widget with the parameter values from the current model state.
The validation mode is particularly useful for models with long computation times. In that case, triggering a model update every time a parameter changes makes it difficult to iterate through different solutions of the model.
If the model contains visible points (Point objects in Grasshopper), they are displayed with small volumes centered on the points in the viewer. This setting lets you scale the volumes to a comfortable size, depending on the scale of the full model.