Beginner's Tutorial for Unfold Faces

Ultimate Unwrap 3D provides a variety of UV mapping projections for different types of situations. Some UV projections create distortion when the object is not perfectly box, cylindrical, or spherical shaped. However, for this tutorial, we will be exclusively using the Unfold Faces tool as it provides distortion free UV mapping.

To demonstrate the power of the Unfold Faces tool, we will show you a couple different ways to unfold a 12-sided dodecahedron. Note that this is an automatic unfolding tool, therefore to use it effectively, you should try to learn how it behaves when it encounters welded or unwelded faces.


First Method

Let's use Ultimate Unwrap 3D to create a dodecahedron primitive. Click Create | GeoSphere, set the number of subdivisions to 0, and choose Dodecahedron (12 faces). Click OK.

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You should see a dodecahedron appear in the 3D Window, as well as a default mapping in the UV Editor. The default mapping of a GeoSphere primitive is created using spherical mapping, but we are not going to use it. Instead, we are going to create a new mapping by unfolding the model.

First, select everything. Use the hotkey Ctrl+A or Select | All from the menu.

Now, click 2D Tools | Unfold Faces and choose Ruling lines and Separate By None. Click OK.

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The model is now unfolded into a 2D pattern. We can use Edit | Rotate | Arbitrary or 2D Tools | Align UVs to rotate our mapping so it is horizontal:

tut_unwrap2a.png

Tip: By default, the operations Move freely, Scale uniformly freely, and Rotate freely are assigned to the hotkeys X, C, and V. You can use these hotkeys to speed up your workflow.


Second Method

What if we wanted to unfold the dodecahedron into two patterns? One way, is to use groups.

In the Scene Window, select the group called Geosphere and delete it. You can delete it by right clicking in the Scene Window and choosing Delete... from the context menu, or by using the keyboard shortcut Delete.

Now, create two new groups. You can add new groups by right clicking on Groups in the Scene Window and choosing Add... from the context menu. By default, new groups are called Untitled, but we can rename them anything we want. Rename them to side1 and side2. Again, use the context menu to rename the groups.

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Now, we can begin assigning faces to our groups.

In the 3D Window, we are going to select 6 faces. First, enable face selection, so click Select | Face. Then use the hotkey S to enable 3D selection. You should see the cursor turn into a crosshair. Then click on the 6 faces as shown below, while holding down the Shift key. The Shift key adds faces to your selection, while the Ctrl key removes them. The outline of each selected face should turn red.

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Now, assign those 6 selected faces to group side1. Do this by selecting side1 in the Scene Window, right click to bring up the context menu, and choose Assign.

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While you still have these 6 faces selected, click Select | Invert. This is just a quick way to select the other 6 faces without having to select them individually. Assign those faces to group side2.

Now that we grouped our faces, we can unfold the dodecahedron again.

First, select everything. Ctrl+A.

Then click 2D Tools | Unfold Faces. But this time, choose Spiral and Separate By Group. Click OK.

tut_unwrap7.png

Our model is now unfolded into two patterns, according to their assigned group.

Note that we used the Spiral option because this creates a spiral unfolding effect.


Third Method

In the previous method, we used groups to create virtual cuts in the model, which separated the faces when unfolding. In this method, we will not use groups. Instead we will actually cut the model by using welding/unwelding techniques.

First, take a look at our model information on the statusbar or by using Info | Scene.

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The model has 20 vertices. This is how many vertices a dodecahedron should have when all of its faces are welded.

What we are going to do is cut the model in half by unwelding group side1 from group side2.

First, select the faces of group side1, by right clicking in the Scene Window, and choose Select from the context menu. The assigned faces of this group should turn red.

Now click 3D Tools | Unweld Faces. If you look at the statusbar, you will notice that the vertex count has increased to 45 vertices. This is ok.

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In the 3D Window, we can now move the unwelded faces apart. Right click to bring up the context menu, and click Modifiers | Move.... Enter a x,y,z value such as (4,0,0) and move the selected faces away from the other part.

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Now that the parts are separated, click 3D Tools | Weld Model. Notice that the vertex count has reduced to 30.

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Select the faces of group side1 again, and move them back.

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What we just did was create a cut between the two groups, so they will not be connected in any way.

For example purposes, we moved the faces apart, then we welded them. This was to show you how unwelding affects faces. We could have used 3D Tools | Weld Faces to get the same result without moving the faces at all.
Now, we can unfold the dodecahedron again.

First, select everything. Ctrl+A.

Then click 2D Tools | Unfold Faces, choose Spiral and Separate By None. Click OK.

tut_unwrap7.png

We get the exact same unfolding, which is what we want. Now, we can fully weld our model back again. Click 3D Tools | Weld Model, and the vertex count should return to 20.


Summary

For the first method, we let Ultimate Unwrap 3D unfold the model for us. This is undecidedly the fastest way to unfold a model, with the least amount of control.

For the second method, we wanted to separate the pattern, so we created groups. This is the next fastest way to unfold a model, with a little more control over how faces are unfolded.

For the last method, we used welding and unwelding techniques to unfold the model. This gives us a lot more control over how faces are unfolded, however this method takes the most time.

That's it! If you have any other questions about unfolding, assignment, cuts, or welding, please let me know.