Geometry Combine

Geometry Combine merges any number of meshes into one — a real merge into a single vertex and index buffer, not a grouping.

That is what matters downstream: one mesh is one draw call, one acceleration structure, one sampling pass, where a dozen separate shapes cost a dozen of each. A scene assembled from parts should almost always be combined before it is rendered, collided with, or sampled.

The inputs are wildcard slots: drop a cable and a fresh slot appears below it, as many as the patch needs.

• Assemble a model — Several Geometry nodes, each placed with Transform, merged into one object.
• One collider for a whole scene — Combine everything, then hand it to a Particle Collider.
• Cheaper rendering — A single Mesh child instead of twelve.
• Uniform post-processing — Weld, Subdivide or Noise applied to the assembly as a whole rather than part by part.
• Scatter then merge — Array produces many copies already merged; Combine joins different shapes.

• Combine then Weld: merging leaves coincident vertices at the seams, and Weld is what removes them.
• Combined meshes share one material at render time — use separate Mesh children when the parts need different surfaces.
• Order the slots deliberately if anything downstream cares about triangle order.
• Watch the counts: combining is free, but the result is as heavy as the sum of its parts.