Blender’s UV Unwrap
Many people have always talked down on Blender’s UV unwrapping, but it almost always comes from the mouth of the inexperienced Blender user. Since Blender started getting a lot of attention in Siggraph 2014, lots of artists from other software praised Blender’s UV unwrapping ability. So, why do so many others blame Blender for their poor UV wrapping? Well, I really don’t know, but I aim to fix the issue causing people to speak so lowly about the UV Unwrap. So, want to see some cool UV tricks kids? Step into my van!
So, you create your model, and now you need to create textures for it. Of course this means you now need to UV unwrap your model if you haven’t already. If you simply choose “unwrap”, then you’ll end up with some questionable results. This is where people start to say that “unwrap sucks”. No, “you suck”, is the reality. The reason for bad UV unwraps is, because of two things: 1. your model is so complex that you need to let Blender know how you want it to unwrap, or 2. you topology is pure crap.
A lot of the times it’s #2, but for the sake of creating a helpful tutorial of sorts, let’s pretend it’s #1. To show Blender how you want things to be unwrapped, is to use seams. Now, a lot of people will tell you that you need to make it unwrap as if you are trying to fold the entire topology into a flat surface, and this is basically right. There are also times when you may have geometry you don’t even have to worry about. Using a seam down the middle of your object can tell Blender you want your object in two halves, where you can throw out the other half, because it will not be seen, but is still needed to help with the shape. I would keep the idea of flattening your object as if it was paper in the back of your mind, but at the same time think about what geometry is actually important. Remember you want to give your textures as much of the texture map as possible to get a good resolution.
Now with all of that off my chest, let’s get on to some Blender UV tools to help you make things a lot easier. First and foremost is the Live Unwrap! If you don’t know about this already, I will accept your request as lord and savior. This allows Blender to automatically unwrap your objects while you model them, as well as when you you add seams (make note of this one especially!).
You can turn this option on for the 3D View, as well as the UV/Image editor, which you want them both to be on. I live to have an extra window open to see my UVs while working on my objects, and you should too after turning these options on. Now you will see how Blender works when adding seams, and topology. You may be trying it now, and be wondering, “Well, it only shows what verts/edges/faces of the model I have selected”, and I retort, “You must turn on the UV Sync in the Image Editor, which you can see the button to the right here”.
Before I wrap this up, I also want to quickly mention the UV Sculpt mode that you can use by pressing “Q” in the UV/Image Editor. It’s basically a Grab Brush for UVs. Pretty cool. Also in the UV/Image Editor is a very important option named “Stretch”, where it will show you how stretched your UVs are in comparison to the model. This is great when you want to make sure your UVs match the model’s topology as closely as possible. Blender will show you how stretched edges and faces are using a color scale (Blue – Red. Red being bad). This is a great way to see just how much distortion you’ll get as soon as you put a texture on your object.
If you watched the Texture Paint tutorial I have on the Youtube channel, you know that with the usual UV unwrapping, you need to turn on the “bleed” option to paint all over them. If you use the Lightmap Pack unwrap, you’ll find that every single polygon is aligned along the X and Y axis, making it to where you can paint with a zero pixel bleed. That’s what makes the Lightmap Pack unwrap so awesome. No only do you not lose any resolution, it makes it work perfect to preserve every bit of the light you paint or bake onto the texture. I remember someone saying that the Lightmap unwrap was crap, and I have no idea why the hell they said that. I’m sure it was another accusation based on ignorance.
So there you go! Enjoy Blender’s awesome UV unwrapping, now that you know what others have taken the time to figure out!