Hi Elliott, This is a great breakdown and very generous in sharing your process and insights, you came a long way from the vending machine days!
Are you planning on releasing the UE4 project to the public? Or only builds? I'd love to play around with it in the editor if possible!
The first step, of course, is an idea. He recommends to sketch your game character either traditionally with paper and pencil or by digital painting. You don’t need to be an exceptional artist to sketch a character and your sketch doesn’t have to win a prize — it’s just a helper for you to get a first impression of the character you are about to design.
Then the base mesh for your character needs to be created, which is a low poly model of your character for which only the basic shape is fleshed out. At this level you can change the shape of your character easily without caring about details. You can use 3D tools like Blender, Maya or ZBrush.
As soon as you are happy with your base mesh you increase the level of details of your model. This means you increase the number of vertices and polygons that 3d models are made of. The more polygons you add, the more details you are able to sculpt in
The model you created is made of millions of polygons, therefore called high poly model and no game engine in the world would be able to process this high number of vertex data, so the next step is topology — by turning your high poly into a low poly model you kind of wrap this model into a new one with a fewer amount of polygons.
But now you ask: “Why should I do this? I will lose so much details!” This is where normal maps come into play. When you have a low and a high poly version of your game character, you bake the topology information of your high poly model to a normal map that will be added to the low poly model. This map is a texture that makes your low poly look like a high poly one and this low poly model with the applied normal map will be used in your game or better to say in your game engine like Unreal Engine or Unity.
To add colors to your model you can either paint onto the high poly model with a tool like ZBrush and project the colors after that on to the low poly version or you can texturize your low poly model with tools like Blender or Substance Painter.
You need to unwrap your low poly model, which is a process of creating a 2D projection of the 3d models polygons. You add seams to the edges of the polygons and unwrap them.