options menu gets sensible default when shape changes

gui.js

@@ -57,6 +57,7 @@ class FourDGUI {
 			options_ctrl = options_ctrl.options(options).onChange((option) => {
 				setVisibility(option)
 			});
+			options_ctrl.setValue(options[0])
 			changeShape(shape)
 		});
 		const options = this.getShapeOptions(shapes, this.params['shape']);