WEBVTT 1 00:00:00.010 --> 00:00:07.000 Vertex groups are groups of vertices within a mesh object that can be referenced for various purposes in Blender. 2 00:00:07.000 --> 00:00:12.000 It is also the foundation of how a mesh and an armature will interact with each other. 3 00:00:12.000 --> 00:00:20.000 Put simply, when done properly, each important bone in an armature object will have a group of vertices assigned to it. 4 00:00:20.000 --> 00:00:25.000 I'm going to demonstrate with this rig, which you can download in the description down below. 5 00:00:25.000 --> 00:00:30.000 As you can see, I can select a bone and it seems to bring a group of vertices along with it. 6 00:00:30.000 --> 00:00:35.000 This allows for bones of armatures to control specific parts of a complex mesh. 7 00:00:35.000 --> 00:00:42.000 You may have heard of vertex groups in other software. Vertex groups are also known as weights. 8 00:00:42.000 --> 00:00:50.000 The term weights also reflects the fact that our vertex groups can assign a certain influence the bone has over individual vertices. 9 00:00:50.000 --> 00:00:55.000 For example, you can have these vertices copy 100% of the bone's movement, 10 00:00:55.000 --> 00:01:02.000 but have these vertices further out be assigned to the same bone but only copy, say, 50% of that bone's movement. 11 00:01:02.000 --> 00:01:08.000 Additionally, you can also assign individual vertices to multiple bones or vertex groups. 12 00:01:08.000 --> 00:01:12.000 In other words, it can be influenced by two bones or more at a time. 13 00:01:12.000 --> 00:01:19.000 This helps blend weights between bones so deformation of certain joints feel organic and natural. 14 00:01:19.000 --> 00:01:26.000 But how do we actually change these vertex groups? How do we edit, create, or manipulate them? 15 00:01:26.000 --> 00:01:33.000 To see any mesh object's vertex groups, simply select it and go into the Mesh Data tab of the Properties Editor. 16 00:01:33.000 --> 00:01:39.000 This is labeled with the green triangle icon and is where vertex groups reside for all mesh objects. 17 00:01:39.000 --> 00:01:43.000 Right now, there are none, but we'll come back to this page later. 18 00:01:43.000 --> 00:01:47.000 Let's begin by creating a simple rig for our cube. 19 00:01:47.000 --> 00:01:55.000 I'm going to go ahead and subdivide this cube a few times in Edit Mode to give us some extra vertices and scale it along the Z-axis. 20 00:01:55.000 --> 00:02:04.000 Then I'm going to add a simple armature object and scale the bone to the length of the cube, subdivide the bone twice, and go back into Object Mode. 21 00:02:04.000 --> 00:02:11.000 Now, in order to deform the cube with the armature, we simply need to parent the cube object to the armature object. 22 00:02:11.000 --> 00:02:17.000 To do this, simply select a cube, then Shift-Select the armature, then press Ctrl-P. 23 00:02:17.000 --> 00:02:21.000 From here, you can select With Automatic Weights. 24 00:02:21.000 --> 00:02:27.000 This is what we've been choosing for all of our previous videos, but let's stop to think about what that means. 25 00:02:27.000 --> 00:02:37.000 Quite simply, clicking this option will create vertex groups for us and assign the vertices within each group automatically with proximity-based weight to each bone. 26 00:02:37.000 --> 00:02:45.000 As you can see, as we deform the armature in Pose Mode, the cube deforms along with the bones in a very smooth and organic way. 27 00:02:45.000 --> 00:02:50.000 I'm going to leave it bent like this for now, and then select our cube mesh. 28 00:02:50.000 --> 00:02:58.000 If we go into the Mesh Data tab again, we can now see the newly generated vertex groups, each named after the bone they are assigned to. 29 00:02:58.000 --> 00:03:06.000 As you can see, our bone names aren't very descriptive, so I'm going to select our armature and rename the bones properly. 30 00:03:06.000 --> 00:03:13.000 Let's call the top one Top, the middle one Mid, and the bottom one Bot. 31 00:03:13.000 --> 00:03:21.000 Now, if we go back to our cube and look at our vertex groups list, we can see that the names of the vertex groups have changed as well. 32 00:03:21.000 --> 00:03:24.000 But what do these vertex groups look like? 33 00:03:24.000 --> 00:03:29.000 In order to visually see our weights, we can enter Weight Paint Mode. 34 00:03:29.000 --> 00:03:34.000 This is another mode option in the top left-hand corner when you have a mesh object selected. 35 00:03:34.000 --> 00:03:40.000 For hockey users, you can press Ctrl-Tab to open a pie menu where Weight Paint is an option. 36 00:03:40.000 --> 00:03:45.000 Now, as you can see, we have a blue cube with green and red markings on it. 37 00:03:45.000 --> 00:03:48.000 This is how weights are displayed in Blender. 38 00:03:48.000 --> 00:03:55.000 Each color represents an amount of influence or weight the vertex group has over specific vertices. 39 00:03:55.000 --> 00:04:04.000 For example, if the vertices are marked with blue, they have a weight of 0%, as in they are not influenced by the vertex group at all. 40 00:04:04.000 --> 00:04:15.000 Whereas if the vertices are marked with red, they have a weight of 100%, or 1.0, which is the maximum amount of influence a vertex group can have. 41 00:04:15.000 --> 00:04:23.000 Meanwhile, green represents 50% weight, and every color in between is a blend of weights between these three colors. 42 00:04:23.000 --> 00:04:32.000 As you select different vertex groups in the list in your Mesh Data tab, you'll see that you can choose which vertex group to display and to edit. 43 00:04:32.000 --> 00:04:42.000 However, these vertex groups are associated with specific bones, so some of you might find it a bit roundabout to not be able to select the bone to see its weight. 44 00:04:42.000 --> 00:04:48.000 As you can see, attempting to select the bone now with left-click doesn't seem to do what we want. 45 00:04:48.000 --> 00:04:56.000 So if we want to select the bones to display their weights in weight paint mode, let's go back into Object Mode and select the armature first. 46 00:04:56.000 --> 00:05:01.000 Then Shift-select the Mesh, and then go into Weight Paint Mode. 47 00:05:01.000 --> 00:05:05.000 Your armature will now be put into Pose Mode automatically. 48 00:05:05.000 --> 00:05:10.000 For left-click users, to select bones make sure you press Ctrl-left-click. 49 00:05:10.000 --> 00:05:13.000 Right-click users can just right-click to select as usual. 50 00:05:13.000 --> 00:05:20.000 To better understand the difference between right-click select and left-click select, make sure to watch our right-click select video. 51 00:05:20.000 --> 00:05:27.000 Anyway, as you may have already guessed, Weight Paint Mode is one way we can edit our vertex groups. 52 00:05:27.000 --> 00:05:31.000 You may have already noticed that your cursor has turned into a circle in the viewport. 53 00:05:31.000 --> 00:05:34.000 This is your weight paint brush. 54 00:05:34.000 --> 00:05:42.000 In Weight Paint Mode, you can actually paint weights onto your vertices, adding said weights to the vertex group you have selected. 55 00:05:42.000 --> 00:05:47.000 We can also open the left-hand side Quick Tools menu to see our other weight paint tools. 56 00:05:47.000 --> 00:05:53.000 These include Blur, Average, Smear, Gradient, and Eyedropper. 57 00:05:53.000 --> 00:05:58.000 If you're familiar with any painting software, you should recognize these functions. 58 00:05:58.000 --> 00:06:02.000 We'll go over each one, but let's start with painting. 59 00:06:02.000 --> 00:06:08.000 Let's say I decided that I want this top bone to have more influence over the bottom of the cube as well. 60 00:06:08.000 --> 00:06:14.000 Let's simply left-click and drag to paint over the bottom half of this cube, making it more red. 61 00:06:14.000 --> 00:06:19.000 By default, as you can see, the weight we paint is set to 100%. 62 00:06:19.000 --> 00:06:27.000 Cool, so what if later I change my mind and I actually don't want weights for this vertex group on the bottom of the cube? 63 00:06:27.000 --> 00:06:33.000 Well, to remove weights, you can also paint a weight of 0% onto the mesh. 64 00:06:33.000 --> 00:06:40.000 To do this, simply open the right-hand side menu by clicking this arrow or pressing the N key and go to Tools. 65 00:06:40.000 --> 00:06:48.000 This is where your brush settings reside, and you can change things such as the radius of your brush, as well as the weight and strength of your brush. 66 00:06:48.000 --> 00:06:53.000 Just to clarify, weight can be seen as the color of what you want your brush to paint. 67 00:06:53.000 --> 00:07:00.000 In other words, the amount of influence you want your vertex group to have over the vertices you paint. 68 00:07:00.000 --> 00:07:04.000 Whereas, strength represents opacity of the brush. 69 00:07:04.000 --> 00:07:13.000 In other words, setting the strength to anything lower than 1.0 will allow your brush to slowly mix with the existing weights of the mesh as you click, 70 00:07:13.000 --> 00:07:17.000 until it reaches the goal color you set in the weight slider. 71 00:07:17.000 --> 00:07:27.000 On the other hand, setting the strength to 1.0 will completely replace any color beneath your brush with the color or weight you set in the weight slider. 72 00:07:27.000 --> 00:07:31.000 The radius of your brush refers to your brush size. 73 00:07:31.000 --> 00:07:37.000 Hotkey users can actually press F while in the viewport to change your brush size whenever you want. 74 00:07:37.000 --> 00:07:41.000 Simply right-click to cancel and left-click to confirm. 75 00:07:41.000 --> 00:07:45.000 Now that we know all of this, this should start making a little more sense. 76 00:07:45.000 --> 00:07:49.000 What we want to do is paint out the bottom influence we painted in earlier. 77 00:07:49.000 --> 00:07:51.000 So, how should we do this? 78 00:07:51.000 --> 00:07:57.000 Well, we want to completely erase the current heavy red weights with empty blue weights. 79 00:07:57.000 --> 00:08:02.000 So, let's set our weight to 0, which essentially sets our color to dark blue. 80 00:08:02.000 --> 00:08:10.000 And to replace the heavy red color completely as we paint, we're going to want to make sure our strength is at 1.0. 81 00:08:10.000 --> 00:08:15.000 Now, as we paint over the red, you can see that our blue paintbrush is erasing the weights. 82 00:08:15.000 --> 00:08:18.000 But here's something important. 83 00:08:18.000 --> 00:08:25.000 If we rotate our perspective around the object, you may notice that we are having some issues painting behind the mesh. 84 00:08:25.000 --> 00:08:28.000 This is because it's behind the geometry in the front. 85 00:08:28.000 --> 00:08:40.000 We can't, of course, simply rotate our mesh while painting, but that can be tedious and doesn't always solve the issues where there's complex detail in the geometry or geometry within geometry. 86 00:08:40.000 --> 00:08:47.000 So, how do we paint through a mesh so that we influence the vertices behind geometry as well? 87 00:08:47.000 --> 00:08:51.000 For that, we need to go over two of our options we have for our brush. 88 00:08:51.000 --> 00:08:59.000 If we look at our tools tab on the right-hand side, we can see under our brush settings that we also have an options section. 89 00:08:59.000 --> 00:09:04.000 Let's expand this, and immediately you'll see a few checkboxes. 90 00:09:04.000 --> 00:09:11.000 Feel free to read more about what each of these settings do in the documentation, or hover over them for a tooltip. 91 00:09:11.000 --> 00:09:13.000 But we will be going over these two. 92 00:09:13.000 --> 00:09:17.000 Front faces only, and 2D falloff. 93 00:09:17.000 --> 00:09:24.000 Front faces only simply means that your brush will only paint onto the vertices and faces that it can directly see. 94 00:09:24.000 --> 00:09:29.000 This means that any geometry hidden behind other geometry will not be painted. 95 00:09:29.000 --> 00:09:39.000 Turning this option off by itself is great for painting crevices or folds, where the geometry you would want to paint happens to be sandwiched or hidden behind nearby geometry. 96 00:09:39.000 --> 00:09:46.000 It's also useful for painting through an object onto the backside of the geometry, kind of like what we want to do. 97 00:09:46.000 --> 00:09:51.000 However, when we uncheck this, it still doesn't seem to paint all the way through. 98 00:09:51.000 --> 00:09:53.000 Hmm... 99 00:09:53.000 --> 00:09:55.000 Well, that's because of this second option. 100 00:09:55.000 --> 00:09:57.000 2D falloff. 101 00:09:57.000 --> 00:10:05.000 By default, 2D falloff is turned off, meaning that our default brush actually uses a 3D falloff. 102 00:10:05.000 --> 00:10:11.000 This means that our brush shape is more like a sphere being dragged along the surface of the mesh as we paint. 103 00:10:11.000 --> 00:10:19.000 Therefore, the falloff will only influence vertices that are nearby the contact point your sphere initially makes with the mesh. 104 00:10:19.000 --> 00:10:24.000 Having a 3D falloff makes a lot of sense when you're trying to paint a mesh. 105 00:10:24.000 --> 00:10:30.000 For one, it feels like a real brush, affecting only the vertices closest to where your brush meets the mesh. 106 00:10:31.000 --> 00:10:36.000 Meanwhile, 2D falloff is more like a cylinder that pierces through your mesh. 107 00:10:36.000 --> 00:10:40.000 This mode will paint anything that your cursor happens to touch. 108 00:10:40.000 --> 00:10:46.000 With front faces only turned on, the 2D falloff brush acts more like a spray can. 109 00:10:46.000 --> 00:10:53.000 And with front faces only turned off, we get to actually paint all the way through our mesh. 110 00:10:54.000 --> 00:11:03.000 Now that we understand these two settings, let's turn off front faces only and turn on 2D falloff to make sure we're thoroughly removing weights. 111 00:11:03.000 --> 00:11:08.000 Another way to completely remove weights from a vertex group is to simply go into edit mode, 112 00:11:08.000 --> 00:11:13.000 select the vertices you want to remove weights from, and go to the vertex group tab. 113 00:11:13.000 --> 00:11:18.000 Make sure the correct vertex group is selected in the list and click remove. 114 00:11:18.000 --> 00:11:22.000 This should remove the vertices from the vertex group entirely. 115 00:11:22.000 --> 00:11:27.000 In the same way, you can also assign weights to a vertex group in edit mode as well. 116 00:11:27.000 --> 00:11:32.000 Let's apply a weight of 100% to the top third of this cube again. 117 00:11:32.000 --> 00:11:42.000 Simply select the vertices you want to assign weights to, change the value of the weight slider under the vertex group list to 1.0, and click assign. 118 00:11:42.000 --> 00:11:47.000 We can then go back into weight paint mode to see these new weights visualized. 119 00:11:47.000 --> 00:11:53.000 For those of you who are curious, while in edit mode, if you select a vertex group from the list and press select, 120 00:11:53.000 --> 00:11:59.000 it will select the vertices in that vertex group, and deselect, will deselect the vertices. 121 00:11:59.000 --> 00:12:07.000 Alright, now let's go back into weight paint mode and take a look at the other weight paint tools we have in our quick tools menu. 122 00:12:07.000 --> 00:12:12.000 Blur is a very helpful tool to use when looking to paint a natural falloff. 123 00:12:12.000 --> 00:12:20.000 Average does something similar, but specifically averages everything under its influence, smoothing sharp contrast areas. 124 00:12:20.000 --> 00:12:25.000 Smear allows you to carry weights over from one place to another with a falloff. 125 00:12:25.000 --> 00:12:31.000 And Gradient lets you paint a gradient starting with your selected weight and blending into the existing weights. 126 00:12:31.000 --> 00:12:34.000 Simply select left click drag to use. 127 00:12:34.000 --> 00:12:40.000 Keep in mind for the gradient tool, your weight and strength settings will be separate and above your brush tool, 128 00:12:40.000 --> 00:12:45.000 as the gradient tool does not use your brush, but rather a vector. 129 00:12:45.000 --> 00:12:51.000 And of course, the eyedropper tool allows you to quickly select weights by sampling the existing weights on your mesh. 130 00:12:51.000 --> 00:12:59.000 Now, weight painting for rigs is great, but it's important to know that vertex groups are not exclusively used for rigging. 131 00:12:59.000 --> 00:13:06.000 In fact, you can use them to affect modifiers, particles, physics and more. 132 00:13:06.000 --> 00:13:08.000 Let's take a look at that real quick. 133 00:13:08.000 --> 00:13:12.000 First thing we'll do is add a monkey mesh for easy visualization. 134 00:13:12.000 --> 00:13:19.000 If we go into the modifiers tab, we can add a modifier and see if it has a vertex group input field. 135 00:13:19.000 --> 00:13:26.000 Not all of them do, but certain modifiers, such as wireframe, include this input field for further customization. 136 00:13:26.000 --> 00:13:31.000 Let's add a wireframe modifier and see how it looks on our monkey. 137 00:13:31.000 --> 00:13:36.000 As you can see, it turns our entire mesh into a wireframe version of it. 138 00:13:36.000 --> 00:13:44.000 This is cool, but I still want to see my monkey mesh too, so I'm going to uncheck this option here called replace original. 139 00:13:44.000 --> 00:13:49.000 Great, but now what if we only want a specific part of the mesh to be wireframe? 140 00:13:49.000 --> 00:13:53.000 Well, for that, we can create a vertex group. 141 00:13:53.000 --> 00:14:01.000 To do that, let's go back into our mesh data tab in the properties editor and click the plus icon under vertex groups. 142 00:14:01.000 --> 00:14:05.000 We can rename the vertex group by double clicking it in the list. 143 00:14:05.000 --> 00:14:09.000 Let's call this one wireframe group. 144 00:14:09.000 --> 00:14:16.000 From here, we can actually go into edit mode and select all the vertices in the ear with the box select tool. 145 00:14:16.000 --> 00:14:25.000 Then go to the vertex group options, make sure wireframe group is still selected in the list, and drag the weight slider to 1.0. 146 00:14:25.000 --> 00:14:27.000 Then click assign. 147 00:14:27.000 --> 00:14:31.000 Now we can go into object mode and see if anything has changed. 148 00:14:31.000 --> 00:14:34.000 No, not yet. 149 00:14:34.000 --> 00:14:41.000 Ah, that's because we still need to go into our wireframe modifier and left click the vertex group input field. 150 00:14:41.000 --> 00:14:45.000 Then select wireframe group from the dropdown. 151 00:14:45.000 --> 00:14:50.000 Nice, now we can see that the vertex group is influencing the effect of the modifier. 152 00:14:50.000 --> 00:14:56.000 Only the ear has been turned into a wireframe while everything else has been ignored. 153 00:14:56.000 --> 00:15:04.000 You can also flip the influence values of the vertex group by simply clicking on the two headed arrow icon to the right of the vertex group. 154 00:15:04.000 --> 00:15:08.000 And now everything has wireframe except the ear. 155 00:15:08.000 --> 00:15:15.000 Meanwhile, increasing the factor slider below, we'll simply blend between the vertex group's influence and what we had by default. 156 00:15:15.000 --> 00:15:22.000 This exact method of using vertex groups as influence can be seen in particles and cloth as well. 157 00:15:22.000 --> 00:15:28.000 Feel free to experiment to better understand how you can use vertex groups for your own projects. 158 00:15:28.000 --> 00:15:35.000 I hope this gives you a fundamental understanding of how to create, use, and edit vertex groups in Blender.