WEBVTT

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UV mapping and unwrapping is the process of skinning your 3D object onto a 2D surface

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for texturing.

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If you want your image textures to properly project onto your mesh, this process is very

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important.

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But what does a UV map actually look like?

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What does it do?

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Well, let's go ahead and show you.

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Simply select your object and go into edit mode.

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Select your entire mesh by pressing A. Then go to your image editor and change it to the

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UV editor in the top left hand corner.

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This is basically the same thing as your image editor but will display your selection's

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current UV map over any image you choose for reference.

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It's also got a few extra settings, specifically for UV editing.

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Alternatively, you can also go to the UV editing workspace which will bring you to the UV editor

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automatically.

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As you can see, our default cube already comes unwrapped as do most of our primitive meshes.

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This is the UV map of our cube.

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So instead of explaining it to you, I'm going to demonstrate how UV mapping works with

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an image texture.

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All I'm going to do is navigate to a file in my file browser and drag it to my shader

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editor as an image texture node.

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You can see that our UV editor automatically displays the image from our image texture

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node we have selected in the shader editor.

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But then, why is our cube still white?

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Well, to actually apply this image to our shader, simply click and drag the color output

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into the base color input of our shader node.

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If your texture isn't showing up, make sure you're in look dev or rendered mode in the

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viewport.

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To understand UVs, let's go into the UV editor and select some faces.

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You can choose a selection mode in the UV editor just like you can in edit mode in the

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viewport.

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This will allow you to edit the UVs like you would a mesh.

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G, S, and R hotkeys also work the same as usual.

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However, we also have some extra tools in the toolbar.

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To transform without hotkeys, simply select the transform tool.

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As you drag things around in the UV editor, you'll notice our image is distorting a little

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bit on the cube.

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For example, we can see that this square here is correlated with this square on the cube

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if we simply move it around a bit.

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We can also scale everything up to repeat the texture across the mesh.

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It's important to note that by default, the UV editor will only show the vertices, edges,

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and faces you have selected in the 3D viewport.

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This also helps make it clear which face in the 3D viewport correlates to which face

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in the UV editor.

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For example, we can go into face select mode in the viewport and select the face.

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That will isolate the corresponding UV face in the UV editor.

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However, you can also flip this function and have the UV editor drive what face you have

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selected in the viewport.

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To do that, simply click this opposing arrows icon on the very top left of the UV editor.

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Keep in mind if you don't see all the buttons here, you can expand the UV editor or scroll

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along the top bar.

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With this mode toggled, we can now go into face select mode in the UV editor and select

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faces in our UV map, which will then select only the corresponding face in the viewport.

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Which function you want to use is up to you.

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I typically work with the default function as it keeps my UV editor clean.

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Now that we understand the UV editor and have an image projected onto our cube, let's

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go and take a look at the different unwrapping algorithms we can use.

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Unwrapping refers to the process of taking a 3D mesh, unraveling its faces and lying

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them out on a 2D surface.

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To begin unwrapping, simply go up here to the UV menu or press U. Even though our cube

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is already unwrapped, these are different unwrap algorithms that we can use.

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Unwrap is your standard unwrap algorithm.

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This simply takes into account what seams you have marked, which we'll get into in

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a little bit, and unwraps your mesh accordingly.

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Smart UV project is one of my favorites and is great for unwrapping things quickly and

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roughly.

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Light map and follow active quads are similar but have their own algorithms.

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Cube, cylinder and sphere projection are algorithms most fitted for objects similar in shape to

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the name of the algorithm.

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Project from view is a very powerful tool that essentially takes what you see in the

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viewport and flattens it as your UV map.

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This is a very basic way of unwrapping your mesh and will not hold up from different

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perspectives but can be used selectively to great effect.

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Project from view bounds simply stretches the resulting UV across the UV editor.

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I'm going to demonstrate this one real quick so let's go ahead and select project from

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view.

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As you can see, the image projects pretty well on our cube from this perspective.

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However if we rotate our perspective, you can see that the image is now stretched across

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the sides that are perpendicular to our view from before.

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That's because as you can see in our UV editor, there are not enough pixels for those faces

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in the UV map.

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Now you may have noticed that we can't get the original mapping of our cube back.

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Pressing the unwrap option doesn't seem to do anything because our cube is already unwrapped.

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So let's go over exactly how to use the basic unwrap function.

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To do this, we need to mark some seams.

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Seams are the edge loops where you specify for blender to cut open your mesh when skinning

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it.

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Simply select the edge loops you wish to mark or clear before clicking each option.

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So let's go into edge select mode and select these three edges.

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I'm going to do the same thing on the other side of the cube.

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Then I can click mark seam in our unwrap menu to mark these edges as where we want to cut

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open the mesh.

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This will make them appear slightly redder.

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Then I'm going to go ahead and select this edge as well and do the same thing.

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Now I can select all of my mesh and go to the unwrap menu and select unwrap.

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As you can see, we have something more similar to what we had before.

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In case you don't understand why I chose the seams that I chose, let me walk you through

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my thought process.

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The arms of the cross we see in the UV map are these faces here.

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They needed to completely detach except for one connected edge, so I marked seams on the

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three other edges of each of these faces.

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Then we simply needed to separate the head of the cross from the tail of the cross.

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That's what this seam was for.

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As you work with your own meshes, you'll get a feel for what seems to work best for

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you to get the UV map shape you want.