Quick tips: Z's Geometry Nodes Cookbook

[zeroskilz]

Say you have a simple hard-surface shape consisting of a couple of primitive components like this:

… each with their own modifiers, etc.
If you wanted to use cycle’s Bevel shader node, the result shows obvious seams between the separate components:

… currently, you have to apply all the modifiers and join the objects for the Bevel material node to work, so here is the Quick-Tip:

Say your components were in some collection called “Raw”… add a new object (calling it “Joined Objects” here)

…and create a geometry node group for it that looks something like this:

That will get GN to do the “join”, allowing you to continue working on the components non-destructively.

[Charles_Weaver (Chuck)]

Hey, nice tip! Thanks for sharing!

[Charles_Weaver (Chuck)]

Override Field

Sometimes, in a nodegroup, you want to default to a certain input (usually position), but use a custom input if one is plugged into the socket.

To do this, take the range of the input using the Attribute Statistic node and compare this value against 0. If it is 0, use the default value. Use the custom value otherwise.

Make sure to set the default value to 0, and hide the value of the socket.

[Charles_Weaver (Chuck)]

Merge by Index

The merge by distance node is limited. It allows you to limit the merging to a selection, but doesn’t let you choose exactly what gets merged with what. This setup allows you to input an index instead. Points with the same index will be merged, and points with different indices will be ignored, regardless of location. This gives you a lot of control over merging, letting you weld islands that are touching, without accidentally fusing them together.

First, capture the position attribute. Set the position of each point to the index, and merge by distance. Set the position back to the original position.

Usage:

There are a lot of advanced index math techniques, but to reproduce the result above, simply capture the indices of both meshes before joining, and add them together. Merge the points using this as the index.

[Charles_Weaver (Chuck)]

Manifold Solidify

By default, when extruding a planar mesh (such as a grid or filled curve), the bottom is left open, resulting in incorrect topology.

To properly solidify a mesh, flip the faces of the original geometry, and join it with the extruded geometry. Merge by distance afterwards to weld them together.

Advanced Technique: Offset

Using some math, you can offset the original geometry along the face normals. The setup above will replicate the offset of the solidify modifier.