Since the version 1.0, you are now able to create actions on your meshes on your scenes using the Actions Builder.
Starting with the Actions Builder? Take a look at: https://medium.com/babylon-js/actions-builder-b05e72aa541a#.mlsd7ksra.
The Actions Builder is reachable using the "Behavior" edition tool. Just select a mesh or the scene in the graph tool (on the right of the editor) and click the "Behavior" tab (on the left of the editor). Then, open the Actions Builder
Once opened, you are able to add actions and conditions raised by triggers. If you want to cancel your modifications, just click the button "Cancel". Else, to save your modifications, just click the button "Save" of the window.
Once you click the button "Play..." in the editor, the actions you created will be automatically used. Then, you are able to test your actions live.
Anyway, if you want to test, the version 2.0 of the Actions Builder (in preview) is available in the editor. To use it, select the menu "Tools -> Actions Builder" in the main toolbar. Once opened, just select a mesh or the scene in the graph tool and the Actions Builder will catch it automatically.
The Actions Builder V2 comes with these new features: