Geometry Nodes Snippets
Geometry nodes in Blender can be extremely useful, but they do have their own learning curve. Currently, in 3.0, geometry nodes have a decent set of operations of scattering, instancing, and working with curves to create linear elements, arrayed and rotated instances, etc.
Coming from extensive professional experience with Grasshopper, Geometry Nodes feels a bit clunky in some ways and in others it feels extremely lean.
I would like to show some basic geometry node functions that are quite different than doing a similar operations in Grasshopper. Many of these examples have been gathered with support from the Blender community, especially the Geometry Nodes thread on blenderartists.org.
The list so far contains:
offset a curve
get coords of first and last pts of curve
instance and rotate elements along a curve
cull Nth instanced element
change location of culled element
slide points along a curve
morph a mesh between two curves
The best way to learn is by copying! That’s how I learned Grasshopper initially, and how to work with the shader nodes for materials in Blender. So, feel free to use these snippets for your learning process. The list will expand over time, so it may be a good idea to come back every once in a while. If you would like to support me and get access to some of the files, they are available on Patreon - patreon.com/uhstudio. If you would like to tag us, use the #uhstudioacademy tag
Offset a curve
This is one of the most important and at the same time quite basic operations. With the usual intent being on starting with a single curve and building up the geometry from that point on.
Get first and last points of curve and a create a line
This is tricky, until you wrap your head around it. There is no way to access an item in a list easily. Instead, there is a rather chunky Attribute statistic node that allows to get the coordinate of a point extracted from the separate geometry node.
Instance elements along a curve
Another typical situation is the instancing with rotation along a curve.
Cull Nth element.
To remove every third point, we would use the Modulo math operation, where we divide the index number by 3, so we would get a pattern of 0,1,2,0,1,2
Change the location of the culled element
The example above generates a pattern of 0,1,2,0,1,2. We can use a boolean node to get a patter that look like this: 1,1,0,1,1,0. Zeroes get removed from the selection
Slide points along a curve and rotate instances
This is similar to the previous example, however in this case, we introduce the ability to slide the points along the curve. Courtesy of @Poligonete
Morph a mesh between two curves
Here we start with a plain grid that has its mesh gets the same number of y vertices as subdivisions of the curves. Then, the curve points are used as the updated positions of the mesh vertices. Courtesy of @Xeofrios