Dev Journal 02 (10/04/18) Digital Taxidermy: UVs and Textures

Okay, as I promised at the end of my last journal entry, I've remade The Horror with a somewhat more optimal, low-poly model. Visually I'm much happier with it, and while there are some aspects that are sloppy -- the hair geometry is a little all over the place -- I think it's coming together much better. As of now, we'll be working with this model:

Just doing some yoga, gotta keep those joints loose when you're making a fighting game character.

I know, this is a big jump from our previous entry, don't fret! I'll walk us through it in sections.

UV Unwrapping

This is one of my favorite parts of the character creation process. Character models need to be textured, but you can't just slap on an image file and call it done. A UV map basically takes the geometry information on a model and unfolds it to be laid out flat to then be textured in an external program such as Photoshop, as I used in this case. This all might sound more simple than the process entails though. Maya doesn't initially concern itself with UV maps until you indicate that you want a proper UV map and go to work on it yourself. If it does, the available map will likely be a series of overlapped geometric shapes that won't do us any favors toward texturing our model. There are automatic UV creators in Maya's editor which provide good starting points, but to make an optimal, efficient map you'll need to put in a fair amount of manual work yourself.

Let's take a look at the UV editor as it processes a model. I didn't document the creation of the new model above, but we can take a look at the process by using the old one. Let's first use the automatic creation button on the UV editor:

So right off the bat we see the UV vaguely resembles a few pieces of the character, the bottom left objects are the front and back pieces of the model's shirt turned sideways. You can see the green selected face on the UV matches up with the front of the model's arm in the viewport, this demonstrates how the model's faces connect to those of the UV.

More importantly, take a look at the white seams splitting up parts of the model, and bordering the pieces of the UV. Those are cuts in the model to help lay everything out flat. Maya cut up our model for us to lay everything out flat, but at the same time, it's a bit destructive and will split apart many small pieces unnecessarily. Luckily, we can select those edges and sew them back together, then flatten them back out. We need to be careful with this process, but with a little effort, we'll have a much more complete, efficient UV map.

While often a time-consuming process, you can see how much more optimized our model's UV is now, each section is split into logical points, such as shirt, pants, hands, feet, head, etc. From here we can save out a snapshot of these selected UVs and bring it into Photoshop,

Even using basic colors we can get an idea of texturing, really the UV unwrapping is the difficult part, once you have those flat surfaces to work with it's as simple as any other form of art asset creation. My example here isn't super optimized, and the model itself has some weird and complicated geometry that would make detailed texturing hard to work with, but we have enough to get the concept down. That's it for texturing our model, next time we'll talk about creating a skeletal rigging system that will let us animate our character once it's bound and the joints are given proper influence over the model's "skin" via weight painting and Unity's component editor using vector selection on appropriate parts of our model. Then, finally, we can go headlong into animation, building this character for a fighting game!