# [Introduction to Blender] Using modifier tools (3) Generate (Geometry Nodes)

In this article, I will introduce the function and simple usage of Geometry Nodes.

In the first article, I introduced the three functions of the Generate modifier (Array/Bevel/Boolean) as an introduction to the modifier tool.

In the second article, I introduced another three functions of the Generate modifier (Build/Decimate/Edge Split).

## What is Geometry Nodes?

Geometry Nodes is a function that was added in version 2.92.
As the name implies, you can edit them in node format.
You can use mathematical formulas to create objects that move in a different way than with the existing functions.

## Trying to use Geometry Nodes

As with other modifier tools, you can add modifiers by clicking on the tool icon.

Geometry Nodes

To edit a geometry node, let’s switch the screen to the upper left icon.

Switch to Node Geometry Node Editor with the upper left icon.

You can increase the screen from the upper right corner of the screen (click to confirm)

## Create a motion graphic

Let’s create a motion graphic using the vertex data of the plane.
We will follow the steps below.

1. Create a plane as a base.
2. Assign a set of Spheres to the plane
3. Set up the motion
4. Set the object that moves the Sphere

Completed image (click to confirm)

First, select the default cube -> [X] to delete it, and [Shift+A] to add a plane.

At the top of the screen, [Shift+A] -> Add Plane

[Tab] to switch to edit mode and subdivide the plane.

Right-click -> Subdivide

Change the “Number of Cuts” value to 10 in the menu at the bottom left to make it even finer.

Number of Cuts

After deselecting the plane, add a Sphere.

Switch to object mode by pressing [Tab], then [Shift+A]→Sphere.

Select the plane again and add geometry nodes from the modifier tool.

Geometry Nodes

Then press [Shift+A] on the Geometry Node Editor to add a node called Point Instance.

Move the cursor to the location where you want to add the node (in the case of Point Instance, between Group Input and Group Output), and click to connect it automatically.

Point Instance (click to confirm)

I added it from the Point menu, but it is convenient to search for it by typing its name in the Search section.

When you want to delete a node, click it and press [X].

Select a node and press X to delete it.

### Assigning a Sphere

Click on the ■ of the Object in the Point Instance node and select the Sphere.

You can also use the eyedropper mark and click on the object directly.

The plane will change with the assigned Sphere and look like this.

Each vertex of the plane has a Sphere assigned to it.

Adjust the size of the Sphere because it is too large for the plane.

Select the Sphere

Use [Tab] to switch to edit mode, and then [S] → move the cursor to shrink the Sphere.
The size should be small enough that all the spheres do not overlap each other.

Click to confirm

### Change the size of the Sphere with Attribute Fill

Use [Tab] to switch to object mode, select a plane, and switch to geometry node editing.

Use [Shift+A] to add a node called Attribute Fill between Group Input and Point Instance.
In this node, you can enter an attribute in the Attribute field and change the attribute by adjusting the value below it.
In this case, we will enter “scale” here, but other default attributes such as “position” and “rotate” are also available.
You can also enter other attributes and they will be created.

Attribute Fill

Now we can easily change the size of the sphere.

The value of the Attribute Fill is linked to the change in the size of the sphere (click to confirm).

### Mixing Attribute Nodes with Attribute Mix

The next step is to add an Attribute Mix between the Attribute Fill and the Point Instance.
This node mixes the two Attribute nodes and creates a new Attribute node.

Attribute Mix

The changes are as follows

Attribute Mix

• Changed from Mix to Add
• Changed from B:Attribute to Vector
• Change the value of the third row of B: to 1.0
• Enter “position” in the “A” field
• Enter “position” in the “Result” field

You can see that the position of the sphere is also moved by changing the value of Factor.

Click to check

### Moving Some Spheres with Vertex Group and Vertex Weight Proximity

Let’s add a Sphere to move some Spheres.

In the window at the top of the screen, press [Shift+A]→Empty→Sphere

S key -> move the cursor to adjust the size

Select the Plane again and select the Object Data Properties icon.
Then click on the + button in Vertex Groups to register the plane.

Vertex Groups

Click [Tab] to switch to edit mode, then click Assign to assign the selected plane.

Assign

Go back to Modifier Properties and add Vertex Weight Proximity.
I’ll introduce this tool in detail in another article.

Modifier Properties

Vertex Weight Proximity

Assign the “Group” that you just registered to the Vertex Group item and Empty to the Target Object.
Set the Proximity Mode to Geometry.

Assign each object in a different order (click to confirm).

### Edit the Weight Paint

Once the Geometry Nodes are hidden, switch to Weight Paint mode from the icon in the upper left corner.

Weight Paint

Adjust the Lowest value to create a gradient circle in the center, as shown in the screenshot.
The size of this circle will be the range of influence when moving the Sphere assigned to the plane later on.

Since the plane is small, I set Lowest to 0.5.

### Adding and editing the Attribute Mix

Click on the icon in the upper left corner to return to object mode.

1. Select the Plane
2. Click on the display icon of the geometry node in Modifier Properties to display the assigned sphere again

Select Plane -> Redisplay Sphere -> Redisplay Node and Edit

Once you have selected the Attribute Mix node, copy and paste it into the new node between the original Attribute Mix and the Point Instance.

Then edit the node you added.

Change the node values, etc.

• Change the Factor from Float to Attribute
• Enter the Group (the name of the Vertex Group you just registered) in the second Factor field.
• Adjust the value at the bottom of B:.

Now all the settings are complete!
Select Plenty, click [G], and move the cursor to see the Sphere moving with it.

There are many more functions in Geometry Nodes alone, so please try them out.

The assigned Spheres are moving together (click to confirm).