For the UDIM part, all the exciting stuff happens in the fragment shaders, as that’s the shader that applies the textures, but just to make sure we covered everything, this is the vertex shader part of the vehicleShader, that simply sets the position to the position it has in your 3D model, unchanged. When we looked at the rendering pipeline earlier, I mentioned there’s a vertex shader, and a fragment shader.

The story of how a single shader abuses UDIM, in a non-standard way, to implement a flawed material library, and became the de facto standard for all vehicles and implements in FS19. Because most readers are probably here because they just want to know ‘how to UDIM their tractor/truck’, we’ll have a detailed look at what they did, how they did it, and how you can use it first. This interpretation goes beyond the basic definition of UDIM, and it violates the UDIM standard. They used a very specific implementation for interpreting the UDIM tiles in a model. In the vehicleShader however, Giants did something more than just that. Now from the introduction about UDIM, you know that UDIM is basically nothing more than unwrapping parts of your model into different UV tiles, so you can assign different textures to them. For that, we need to take a closer look at the vehicleShader, because that is the shader that ‘supports UDIM’. You’re absolutely right, and we’re almost there.

Shaders included in FS19 I thought this article was about UDIM?! There’s plenty of shaders included, the buildingShader and the vehicleShader probably being the most used for, as the name implies, buildings and vehicles. This is familiar territory for most modders, as you select these shader XML files in GIANTS editor. The way to specify these hooks, and tell the game engine how you would like to affect the way something is rendered, is through shader XML files. Giants actually provided us with an extensive and very open framework allowing us to affect almost every aspect of how the game looks, and behaves. This is something very few people are aware of. Hooks are moments in the execution of the shaders where you can insert your own code to be executed. The good news is, Giants included a huge number of so called ‘hooks’ in them. The actual shader code is part of the internals of FS19, so I can’t show you a fragment of it, but in case you’re curious and know your way around the game files, they are included in the shared/shader.gar archive. The next one is the pixel shader, also called fragment shader, that colors them.įS19 has implemented these shaders in Cg, a shader language based on the C programming language, developed by Nvidia. It’s main purpose is to determine the position of your vertices.

There’s two moments in the pipeline where we can control what the end result will look like. The bag of vertices on the left? That’s your 3D model. The diagram above shows a simplified view of the graphics rendering pipeline.

Shaders fs19