Here's an example I found on Sketchfab but I'm not actually 100% sure on the usage rights for it so I think it'd be great to have one exclusive to Storyboarder. This could work as either a model like I have here or just a skybox. Something to give the edges of urban environments feel a bit fuller. Some alternatives like trees or mountains for natural environments would be great too, but definitely a city one since most of the Storyboarder stages are urban environments right now.