2D Repeaters are powerful nodes that make composite shapes by repeating an input shape. The composite shape is then often used as a void in a ShapeMerger to cut a fenestration pattern into another shape. For example, and ArchShape could be repeated using a LinearRepeater2D to create an arcade wall.
Another example is to use two shapes as input to a Repeater2D in order to have them automatically merge (without a ShapeMerger node). Below a HouseShape and a CrossShapehave been fed into a RadialRepeater2D to make this fortress wall with a parapet:
When to 2D vs. 3DRepeaters?
The extrusion of a 2DRepeater will create new mesh data for each repeated shape. This can be inefficient when repeater a Rectangle and then extruding compared with extruding a single Rectangle and then 3D repeating the extrusion, since 3D repetition Instances the original source mesh rather than creating multiple meshes.
For this reason, it is better to use 2DRepeaters when they are needed in ShapeMerger operations.