This vintage gas station is a recent game asset I have been working on. Together with all props, the triangle-count is 20360 (10944 verts).
I decided to go with a high-poly to low-poly workflow to keep the polycount low while maintaining a high visual quality. I first created a blockout of the building and the props.
The blockout was then directly modified to create the high-poly models.
The low-poly models were created by either reducing the high-poly-models to a suitable amount of polygons or by creating new meshes which fit the high-poly-models.
I then created the UV-Maps of the low-poly-models. Whenever possible, I tried to fit the UVs of similar assets into the same material and to stack UVs. This way I was able to save UV-space. For the walls and some parts of the roof I decided to use overlapping UVs since I was using a seamless texture in Unity.
After that I created the mesh-maps based on the high-poly models in Substance Painter. When texturing the model in Substance-Painter, I was using a mix of the materials provided by Substance Painter as well as creating some materials on my own.
Then I exported the textures from Substance-Painter and brought the models and textures together in Unity. I set up the materials with the exported textures and also used some seamless textures from third party-providers (like textures.com, poliigon.com, texturehaven.com, cc0textures.com) and set up a basic scene inside a forest-environment I quickly put together with Gaia 2.
