A great example would be Stefan Garcia's "BrickSpace" mod for Homeworld Remastered.However, he spent a huge amount of time and effort manually optimizing these models. You can't simply build a model in LDCad and export it directly into a game. You have to do things like cut out the internal polygons and "bake" the studs into the textures. Not sure if Stefan ever created a "making of" video. That would be interesting to watch.I also personally messed around with creating a RPG Maker game.Since the graphics are all 2D, you don't need to optimize the models much. However, the engine was not designed with large, moving, and overlapping sprites in mind, so you need to implement lots of "hacks" that slow the engine down (and are also a PITA in other ways).