Sketchup is a former Google product that has been bought by Trimble. It’s a 3D modeling app that comes in a free basic version and premium for professionals. There’s two main reasons for discussing it here – the openness that having a free version brings, particularly from Google because they fostered a community of modelers and developers under it, and the fact that it’s very easy to use.
Modeling can be as easy in Sketchup as pushing and pulling shapes into desired designs. It’s also easy to enter measurements to square things up into accurate models. There’s a 3D Warehouse online full of models already put together by the community if you’re looking to try things out and put a scene together. Not to mention there’s plenty of tutorial videos to be found, both official and unofficial.
I’ve already mentioned Blender as a free 3D tool with a good community behind it. But what I really want to stress with Sketchup is the ease to which creators can mock up sets and props with it. Not too long ago I checked out a copy of the DC Comics Guide to Digitally Drawing Comics by Freddie E. Williams II. Did you know, if you make paths of buildings in Photoshop you can extrude those in Sketchup to make them into models? That sort of cross compatibility is crazy. An artist could build up a library of building elements in 2D and then export them into 3D. There’s tons of plugins and styles out there to use, mix, and match. There are renderers for creating photo-realistic renders of models, for creating better models with more configurable shapes, to giving your models physics.