Understanding the Geometry Node system

The Geometry Node editor is a new feature in Blender 3.0. Over the months, it has evolved into a very useful tool that every CG artist should know. Geometry Nodes is all about procedurally modeling your mesh. This can help with big scenes where you need lots of objects to have variation. For example, if you are making a forest, every tree needs to have a bit of variation; otherwise, the scene will look like a render. To easily add variation to trees, we use Geometry Nodes.

Previously, creators would use hair particles to scatter objects along a mesh. With Geometry Nodes, this is no longer needed. Geometry Nodes will help in scattering all objects just the way you want. There are lots of ways to scatter your objects. We will also go over the various ways to randomize these instances. The idea of Geometry Nodes is to procedurally generate a complex mesh out of a basic and simple input.

Unlike the Material Nodes editor, which does not use a Modifier, the Geometry Node editor is a Modifier that can be applied from the Modifiers tab. This Modifier can be combined with other Modifiers like any other would. The Geometry Nodes Modifier consists of a few parts:

Figure 1.1: The Geometry Nodes Modifier

Part 1 refers to how many times the node tree has been used. If the node tree is only being used by one object, this number will not be there.The button in part 2 allows you to select a node tree out of the different node trees in your project.

Part 3 allows you to link various attributes to this variable. For example, you can link weight paint values with this for a simple stone distribution solution.

The button in part 4 allows you to animate the value of part 5. This can also be done by pressing i on any value field.

Lastly, part 5 defines the current value that is being inputted into the node tree. You can change this value by clicking on it or by holding down your mouse cursor while sliding.

Behind this Modifier lies the Geometry Node system. It consists of various nodes to procedurally model your objects.