Trim textures: a new hope
To understand the concept of using tileable textures or trimsheets that can be reused as much as possible
The mission
To understand the concept of using tileable textures or trimsheets that can be reused as much as possible.
Resources
- Zbrush 2018+
- Maya LT 2018
- Substance Painter 2018+
Trim... What? Tile... Who?
First things first, what is a tileable texture?
A tileable texture, also known as a seamless texture, is a texture that can be repeated across a mesh without the borders being noticeable to the observer.
As you can see, I can expand or make it smaller as much as I want without it giving away a clear visual indication of a seam between the repetitions.
This is the same example with a non-tielable texture. Much worse, right?
The more you tile it or repeat it, the more apparent the repetition becomes. Tileable textures work best when mixed with other tileables via vertex painting or height blends to mask those landmarks that make us go: "Aha! There's the pattern!
Trim textures, also known as a trimsheets, are textures composed of multiple mini textures, whether tileable or not. They are somewhat akin to an atlas or tileset (for those who remember working on RPG Maker :D).
What's it useful for?
Reducing the time for texturing of a general area while maintaining consistency is crucial. Imagine a temple from the Uncharted franchise or God Of War 2018: there needs to be cohesion and connectivity between all the ornaments and motifs throughout a building.
Trim textures are especially useful for PBR (Physically Based Rendering), where you don't need to worry about overlaps in the UVs of the final model. Repurposing trim textures is a super-fast and reliable way to create texture variation and use it in different ways. For example, the same trim can be used for texturing props or for texturing the whole building.
General workflow
This texturing method relies heavily on how you unwrap your mesh and how the trim texture is laid out. You can either start planning the textures first before modeling, or do it the other way around. We'll need to plan it either way because both steps affect the next one.
Let's reuse the textures from the exterior of the Tomb Chaser pyramid to create a simple column that could be reused in the interiors. This is the current trim texture used to beautify the entire exterior.
Yes, it's all a single material!
So, let's createa column divided into sections, and you'll see how quickly you can change the design once we have our geometry there, just by switching the UVs around.
This is going to be our column. As you can see, it has many distinct sections that will be assigned to different parts of the texture. Let's cut those sections in the UVs, right where they change from one section to another.
See how cylinders are unwrapped in a linear fashion? This is key to taking advantage of our texture space and patterns throughout the model.
After this, we can begin modifying the UVs to fit into the preexisting "sections" of the trim texture.
And once that's done, creating variations of this is really, really easy. We just need to move the UV shells around to other trim sections!
Conclusion
We can create variations with the same geometry and the same texture by modifying the UVs of the mesh. We can also make a variation of the texture, and it'll automatically apply to the already UV'd mesh with different colours/patterns as long as you leave the pattern separation consistent.
I hope you’ve learned something new today!
See you around :)
