Hello! I’m Vertex Cat, a freelance 3D artist from Seattle. I design and make low poly game assets and illustrations. Lately I’ve been working a lot with the type of models you see here: low tri-count (of course), unlit with flat, hard-edged vertex colors, and an overall cartoony feeling. It’s a fun challenge to work with these “restrictions” while making sure the model looks good and still represents its real-life counterpart!
One of my newest personal projects is making sets of 5 or 6 models and releasing them as free game asset downloads. (Links are at the bottom of the page.) This scene is to showcase the latest set—five different farm animals—and to test out some new design ideas like the chicken coop and the barn.
Early steps
Even though the scene is very stylized, I still spend a lot of time looking at images of real animals for reference. They’re a useful starting point for making design decisions like “should the sheep have necks” or “where does this udder go”.
I also plan the color scheme at this point. It’s important to do this early on because as far as I know, there’s no way to make permanent, global color adjustments (like editing hue, saturation, value) to the vertex colors themselves… other than manually recoloring every change you want to make. You can do these types of adjustments through materials and post-processing. But if you import it into a game engine, the model will have its original, pre-adjustment colors by default.
To Blender!
I use Blender for almost every personal project. Its object modifiers are really useful, and I like how it handles vertex coloring. Both of these played a big part in making this scene so I’ll talk about them a bit. But first, modeling:
Modeling
The animals use one of two base models. Birds begin life as a cube with a neck and a butt. Four-legged animals are like a weird AT-AT.
The next steps are different for each animal, but generally it’s rounding out the form with edge loops and extruding and shaping a head. For convenience, features like ears, wings, and bird legs are separate meshes and not extruded from the main body.
There’s no particular process for the rest of the models, but this is where I start using object modifiers.
Object modifiers
Modifiers let you make specific types of changes to your model non-destructively. What I mean here is the ability to undo all the changes you made with the modifier simply by removing it. When used properly, it’s really much better than hitting Ctrl+Z as many times as Blender will let you and hoping for the best.
My main modifiers are mirror, array, and lattice. The skin modifier is also a nice one for tree branches and some creature limbs, but I didn’t use that in this scene.
The mirror modifier does exactly what it says. In this scene I used it on all the animals and buildings.
Array is for objects with repeating parts like the chicken coop ramp. You can make changes to all the parts at once and easily adjust the spacing between each. It’s also good for fences and placing multiple windows on a building.
Lattice is sort of like the modifier version of proportional editing, or the warp transform in Photoshop. The results are often more interesting than a standard transformation like scaling because you have greater control over what’s stretched or compressed. It’s great for cartoony styles, where you often want exaggerated sizes, uneven proportions, and curved lines instead of straight.
Lastly, shape keys let you make even more specific non-destructive transformations. I didn’t use any here, but they’re really great so I wanted to mention them! I like this tutorial on chocofur.com.
Vertex color
This is the setup for an unlit, vertex-colored material in Cycles. Adding an Attribute node named “Col” will make a shader use vertex color, and an Emission shader set to strength 1 gives you an unlit material.
For actually applying color in Vertex Paint mode, I go back and forth between selecting faces to fill with color, editing the mesh to make edges where I need them, and occasionally using a gradient effect.
So it’s not so much “vertex painting” but more like “vertex selecting-then-filling”. I use five selection tools on a regular basis, which are Select All, Box Select, Circle Select, Edge Loop Select, and Select Linked. It sounds like a lot, but it really helps to have all these options when selection makes up most of the process.
Select Linked is like two tools in one, because there’s a nice option in the tool shelf for changing delimiters.
In both screenshots, I added a seam where the flower petals meet the stem. With the mouse hovering over the flower petals, I use Select Linked. By default, you get the screenshot at left: the entire mesh selected. But doing the exact same thing with Delimit set to Seam will select only the flower petals. So putting seams in strategic locations gives better control over vertex color fills, and it’s more convenient than selecting each face and more accurate than something like box select.
Sketchfab
I used to make turntable gifs for everything I wanted to post online. I still do it a lot, but it takes a bit of time and effort to get the proper balance between file size and quality and to make sure the camera placement is showing everything I want it to. Sketchfab is a great alternative because these issues don’t apply. I can spend that same time and effort on adjusting colors and backgrounds and such to go one step beyond simply showing the model.
Speaking of adjusting color, I mentioned earlier that vertex color adjustments rely on material or post-processing settings. Sketchfab’s 3D settings let you customize both, so there are a lot of options for presenting the final model as if you’d made all the right color choices on your first try 🙂 All in all, Sketchfab has become a big part of my final editing and presentation workflow.
Conclusion
The set of 5 animals is a free download in the Unity asset store and itch.io. For more on my process, new model set announcements, and the occasional cat appreciation post, you can find me on Twitter and Tumblr as @vertexcat.
Many thanks to Sketchfab for this spotlight and to you for reading!
About the author
Vertex Cat
Freelance 3D artist from Seattle.
