Join Aaron F. Ross for an in-depth discussion in this video Laying out UVs, part of Creating Hair with Maya nHair.
Another important step that we need to take in preparing our model is to set up its UV layout. If we want to paint hair follicles onto the surface, it's absolutely necessary that the UV space be uniform, and this is because there's no equalize function for hair follicles. In other words, if the UVs are not structured well, then the follicles will tend to clump together, and they will not be evenly distributed. So we just want to do a very simple UV projection on here. We don't need to do anything fancy.
We just need to make sure that the UVs are more or less clean and that they're even. I'll select the mesh object. And my advice is to see what you're doing, you'll want to open up the UV Texture Editor window. Go to Edit UVs, UV Texture Editor, and then zoom in a little bit. Use the Alt + middle mouse button to adjust the window so that you can see just the zero to one UV space. And we'll apply a spherical projection onto this object. Okay, and move that over there. And go to Create UVs, Spherical Mapping.
And as you can see, what we get in the UV texture editor doesn't look so good. But we can make some simple quick adjustments to the manipulator here in the main viewport. So, I'll turn this all the way around so that it's projecting from the back of the head. And I'll also adjust these manipulator handles here. As you can see what I'm doing here is I'm moving that so that it's covering more of the surface. You can also scale the manipulator up a bit so it's a little bit easier for you to see. And bring it around a little bit more. Basically you want 180 degree projection or maybe a little bit more.
And you can also move the entire manipulator around, and that's kind of important because you can see we're getting kind of weird stretching here. To fix that, I can move the manipulator. And to do that, I'll need to click on the little red cross up here. Click on that, and that switches my manipulator mode. And I can bring this forward. And now, the projection is basically comforming to the shape of the object much more closely. We just want to end up in a place where none of the UV faces are outside that zero to one area.
Because if they are, then no hair follicles will appear there. I can switch back to the other projection mode here, and play a bit with the manipulator. Just to make sure that we get full coverage there. And it's not absolutely necessary that we take up the entire zero to one space here. We just want to make sure that none of the UV faces are outside that zero to one space. And that's good enough. I can go ahead and close the UV texture editor. I can right click on the object and go back to object mode.
I can just go ahead and delete the history on the object. Edit > Delete by Type > History. And now this object is ready to have applied to it.
- Prepping a model for hair
- Adding nHair
- Setting dynamic properties
- Adjusting clump, curl, and twist
- Painting follicle attributes
- Creating long hairstyles with curves
- Applying nConstraints
- Creating and rendering an nCache