This tutorial by Jayanam shows a fairly easy way how to use the Vertex Proximity Weight with Geometry Nodes. In contrast to the previous tutorial we use now a modifier. This makes it an easier tutorial. And therefore I suggest to start with this tutorial first. Mind that this 9 minutes long tutorial shows first a preparation of the scene. After that, at 4:50, we start with Geometry Nodes. So if you want to speed up you can add a Curve (Circle) in the scene.
Next, you randomize a bit and add a bevel (properties panel > Object data). After that, add an empty and give it a constraint: Follow Path, where the target is the curve. Don’t forget to check the option Follow Curve, and press button “Animate Path”. Now, check if the empty is moving when playing the animation (spacebar). Last step is to select the curve and adjust path animation in the properties panel and then convert the curve to mesh. Also give the mesh a material and a vertex group (all vertices).
One more thing before playing with Geometry Nodes: add a glowing sphere in the scene. We use that to scatter on the mesh. Finally we use the Geometry Nodes now. The idea is to scatter glowing spheres at the place of the animated empty. Around 4:50 in the tutorial we start working on this nodegroup:
Once done, add a vertex weight proximity modifier. This modifier has to be on top of the stack. Now, this is an important part if you are not familiar with the modifier. Namely, the vertex group is the vertex group we created earlier and the target is the empty. So what does this do? This modifier will now set the weight of the vertex group driven by the proximity of the empty. Meaning, there where the empty is in the animation, the vertices close to it get a higher weight value.
Get the vertex weight proximity modifier to work
Now we have the vertex weight proximity modifier, add an Attribute Mix Node as follows:
Mind that in the factor, you fill in the name of the vertex group you created. By default that is Group, but Jayanam names it mesh_vgroup here. Now, there is a very interesting part he says, and I will quote it here:
So what is an attribute? Well, for example the scale that we already randomized. But there is another attribute that we used in the vertex weight proximity modifier which is the mesh_vgroup. And this, I use as factor to mix it with scale and the result is scale again (override).Source: Jayanam
And another important explanation to remember:
So what does it mean? We are multiplying the weight of the vertex group (that is set with by the proximity modifier, which depends on the distance of the empty), with the scale of the points. And with this, the point size in the end is defined by the position of the empty.Source: Jayanam
With this, I hope that this article Geometry Nodes with Vertex Proximity Weight helps you understanding how attributes work in Geometry Nodes.