Why you may want to consider Mid-Poly Modelling (Smoothed Normals Workflow)
Updated: Dec 15, 2019
Working and experimenting with the medium polygon workflow is useful when creating a stylized look and feel, while keeping complexity low.
Mid-poly modelling is used in games such as Alien Isolation, Star Citizen and Cyberpunk 2077. It involves beveling then smoothing hard edges. This is instead of baking a high-poly down onto a low-poly model. Computationally, both workflows are considered equal in regards to vertices.
Looking at these examples of low-poly and mid-poly edges, we can see that there are only ever 3 vertex normals. This is because the hard edge separates one vertex for the 3 faces it is connected to in order to compute the lighting.
The mid-poly example has smoothed edges over the bevel leaving it with 3 vertex normals. This gives the advantage of having a more complex shape to give a stylized effect while reacting more realistically to light. It is important to understand this concept when modelling so you don't work against it.
Mid-poly modelling removes the need to create a high-poly model, so reduces the time spent to create a finished looking asset. Likewise, modeling with the intention of reusing assets with different materials is extremely efficient. Using modular kits can speed up level creation while mid-poly modelling allows materials to be used multiple times.
The main benefit of using a mid-poly workflow in game design is that texturing can be done in-engine by a designer using the same transferable materials. This can create a powerful and cohesive colour pallet, which can be changed quickly and efficiently. To do this, artists need to make tiling textures and properly layout their UVs. A fair argument against mid-poly modelling is that it can be difficult to achieve edge-wear like in Substance Painter. There are The main way around it is to use decals in engine, or have floating geometry in the model. This also means that you can add and remove the wear, or change the way it looks during run-time. This is normally used to display panel seams and bolts without having to model them.
Another plus side to mid-poly is texture quality. Large objects don't require large textures. Just as artists often optimize their textures by using trim sheets, mid-poly continues this. By using different materials on each different part of the model, multiple texture sets can be used while keeping the quality high.
Mid-poly modelling can serve as a way of creating cohesive and unique styles while keeping a game optimized. Designers and artists can work together through the use of modular kits and by reusing and re-purposing textures throughout a game level.