vertex groups are groups of vortices within a mesh object
that can be referenced for various purposes and blunder.
It is also the foundation of how a mesh and an armature will interact with each other
put simply when done properly.
Each important bone in an armature object will have
a group of vertex is assigned to it.
I'm going to demonstrate with this rig which
you can download in the description down below.
As you can see I can select the bone and it
seems to bring a group of vortices along with it.
This allows for bones of armatures to control specific parts of a complex mesh
you may have heard of vertex groups and other software
vertex groups are also known as weights.
The term weights also reflects the fact that our vertex groups
can assign a certain influence the bone has over individual vertex is
For example
you can have these vortices copy 100% of the bones movement
But have these vortices further out be assigned to the same
bone but only copy say 50% of that bones movement.
Additionally,
you can also assign individual vertex is to multiple bones or vertex groups.
In other words it can be influenced by two bones or more at a time.
This helps blend, waits between bones.
So deformation of certain joints feel organic and natural.
But how do we actually change these vertex groups?
How do we edit, create or manipulate them
to see any mesh objects. Vertex groups
simply select it and go into the mesh data tab of the properties editor.
This is labeled with the green triangle icon and
is where vertex groups reside for all mesh objects
right now there are none. But we'll come back to this page later.
Let's begin by creating a simple rig for our cube.
I'm going to go ahead and subdivide this cube a few times in edit mode
to give us some extroverts is and scaled along the Z. Axis.
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.
Now in order to deform the cube with the armature,
we simply need to parent the cube object to the armature object
to do this simply select a cube then shift select the armature,
then press control P.
From here. You can select with automatic weights.
This is what we've been choosing for all of our previous videos.
But let's stop to think about what that means.
Quite simply
clicking this option will create the vertex groups for us and assigned the
vertex is within each group automatically with
proximity based weight to each bone.
As you can see as we deformed the armature in pose mode,
the cube deforms along with the bones in a very smooth and organic way.
I'm going to leave it bent like this for now and then select our cube mesh.
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.
As you can see our bone names aren't very descriptive.
So I'm going to select our armature and renamed the bones properly.
Let's call the top one,
top
the middle one, mid
and the bottom one. But
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.
But what do these vertex groups look like
in order to visually see our weights, we can enter weight paint mode.
This is another mode option in the top left hand corner.
When you have a mesh object selected
for hockey users,
you can press control tab to open up I menu where weight paint is an option.
Now as you can see we have a blue cube with green and red markings on it.
This is how weights are displayed in blender.
Each color represents an amount of influence. Or wait,
the vertex group has over specific vortices.
For example, if the verses are marked with blue,
they have a weight of 0%.
As in they are not influenced by the Vertex group at all.
Whereas if the verses are marked with red,
they have a weight of 100% or one point
which is the maximum amount of influence a vertex group can have.
Meanwhile,
green represents 50% weight and every color in between
is a blend of weights between these three colors.
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.
However these vertex groups are associated with specific bones
so some of you might find it a bit round about to not be able to select the bone
to see its weight
as you can see attempting to select the bone. Now with left click
doesn't seem to do what we want.
So if we want to select the bones to display their weights and weight paint mode,
let's go back into object mode and select the armature first,
then shift select the mesh
and then go into weight paint mode.
Your armature will now be put into pose mode automatically
for a left click users
to select bones, make sure you press control left click,
right click users can just right click to select as usual
to better understand the difference between right
click select and left click select.
Make sure to watch our right click select video
anyway, as you may have already guessed.
Wait paint mode
is one way we can edit our vertex groups.
You may have already noticed that your cursor has
turned into a circle in the view port.
This is your weight paintbrush
in weight paint mode.
You can actually paint weights onto your vertex is
adding said weights to the vertex group. You have selected.
We can also open the left hand side. Quick tools menu
to see our other weight paint tools.
These include blur, average smear gradient and eyedropper.
If you're familiar with any painting software,
you should recognize these functions.
We'll go over each one. But let's start with painting
let's say I decided that I want this top bone to
have more influence over the bottom of the cube as well.
Let's simply left click and drag to paint over the bottom half of this cube,
making it more red
by default. As you can see the weight we paint is set to 100
cool.
So what if later I changed my mind and I actually don't
want waits for this vertex group on the bottom of the cube.
Well
to remove weights
you can also paint a weight of 0% onto the mesh
to do this simply opened the right hand side
menu by clicking this arrow or pressing the N.
Key and go to tools.
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.
Just to clarify. Weight can be seen as the colour of what you want your brush to paint.
In other words,
the amount of influence you want your vertex
group to have over the vertex is you paint
whereas strength represents opacity of the brush.
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
until it reaches the gold colour. You set in the weight slider
On the other hand,
setting the strength to 1.0 will completely replace
any colour beneath your brush with the colour.
Or wait, you set in the weight slider.
The radius of your brush refers to your brush size.
Hockey users can actually press F while in the view port
to change your brush size whenever you want,
simply right click to cancel
and left click to confirm
Now that we know all of this.
This should start making a little more sense.
What we want to do is paint out the bottom influence we painted in earlier.
So how should we do this?
Well, we want to completely erase the current.
Heavy red waits with empty blue weights.
So let's set our weight to zero,
which essentially sets are color to dark blue
and to replace the heavy red color completely as we paint,
we're going to want to make sure our strength is at one point. Oh
now as we paint over the red,
you can see that are blue paint brush is erasing the weights.
But here's something important
if we rotate our perspective around the object.
You may notice that we are having some issues painting behind the mesh.
This is because it's behind the geometry in the front.
We can 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.
So how do we paint through a mesh so that
we influence the vertex is behind geometry as well.
For that we need to go over two of our options we have for our brush.
If we look at our tools tab on the right hand side,
we can see under our brush settings
that we also have an option section.
Let's expand this
and immediately. You'll see a few checkboxes.
Feel free to read more about what each of these settings do
and the documentation or hover over them for a tool tip.
But we will be going over these two
Front faces only
and two d. fall off
front faces only simply means that your brush
will only paint onto the verses and faces
that it can directly see.
This means that any geometry hidden behind other geometry will not be painted.
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,
it's also useful for painting through an object onto the back side of the geometry.
Kind of like what we want to do.
However, when we uncheck this, it still doesn't seem to paint all the way through.
Mm.
Well that's because of the second option
two d. fall off
by default to D fall off is turned off,
meaning that our default brush actually uses a three D fall off.
This means that our brush shape is more like a sphere
being dragged along the surface of the mesh as we paint.
Therefore the fallout will only influence vortices that are nearby.
The contact point. Your sphere initially makes with the mesh
Having a 3D fall off. Makes a lot of sense when you're trying to paint a mesh
for one.
It feels like a real brush affecting only the vertex
is closest to where your brush meets the mesh.
Meanwhile, two D fall off is more like a cylinder
that pierces through your mesh.
This mode will paint anything that your cursor happens to touch
with front faces only turned on
the two D. Fall off brush acts more like a spray can
and with front faces only turned off,
we get to actually paint all the way through our mesh.
Now that we understand these two settings.
Let's turn off front faces only and turn on two D.
Fall off to make sure we're thoroughly removing weights.
Another way to completely remove weights from a vertex
group is to simply go into edit mode.
Select advertises you want to remove weights from and go to the vertex group tab
make sure the correct vertex group is selected in the list and click remove
this should remove the vertex is from the vertex group entirely
in the same way. You can also assign weights to a vertex group. In edit mode as well,
Let's apply a weight of 100% to the top third of this cube again
simply select the vertex is. You want to assign weights to
change the value of the weight slider under the vertex group list to one point. Oh
and click assign.
We can then go back into weight paint mode
to see these new weights visualized
for those of you who are curious while in edit mode,
if you select a vertex group from the list and press select
it will select the vertex is in that vertex group
and de select will deselect. Advertises.
All right
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
blur is a very helpful tool to use when looking to paint a natural fall off
average does something similar but specifically
averages everything under its influence,
smoothing sharp contrast areas.
Smear allows you to carry weights over from one place to another with a fall off
and gradient lets you paint a gradient starting with
your selected weight and blending into the existing weights
simply select left click drag to use.
Keep in mind for the gradient tool
your weight and strength settings will be separate and above your brush tool
as the gradient tool does not use your brush
but rather a vector
and of course the eyedropper tool allows you to quickly
select weights by sampling the existing weights on your mesh
Now wait painting for riggs is great but it's important to
know that vertex groups are not exclusively used for rigging.
In fact you can use them to affect modifiers,
particles,
physics
and more.
Let's take a look at that real quick.
First thing we'll do is add a monkey mesh for easy visualization.
If we go into the modifiers tab we can add a
modifier and see if it has a vertex group input field.
Not all of them do but certain modifiers such as wireframe
include this input field. For further customization
let's add a wireframe modifier and see how it looks on our monkey.
As you can see it turns our entire mesh into a wireframe version of it.
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.
Great. But now what if we only want a specific part of the mesh to be wireframe?
Well for that we can create a vertex group
to do that. Let's go back into our mesh data tab in the properties editor
and click the plus icon under vertex groups.
We can rename the vertex group by double clicking it in the list.
Let's call this one
wireframe group
from here.
We can actually go into edit mode and select all
the verses in the ear with the box select tool,
then go to the vertex group options,
make sure wireframe group is still selected in the
list and drag the weight slider to one point.
Oh
then click a sign.
Now we can go into object mode and see if anything has changed.
No, not yet.
Ah that's because we still need to go into our
wireframe modifier and left click the vertex group input field.
Then select wireframe group from the drop down.
Nice.
Now we can see that the vertex group is influencing the effect of the modifier.
Only the ear has been turned into a
wireframe while everything else has been ignored.
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
and now everything has wireframe except the ear.
Meanwhile, increasing the factor slider below
will simply blend between the vertex groups influence and what we had by default.
This exact method of using vertex groups as influence
can be seen in particles and cloth as well.
Feel free to experiment to better understand how you
can use vertex groups for your own projects.
I hope this gives you a fundamental understanding of how to create
use
and edit vertex groups in blender