Preview Mesh Multi

Comparison is the whole game in 3D work, and sometimes two meshes isn't enough. Preview Mesh Multi is the pack's "I have several candidates and I want to look at them together" node: one mesh_1 required, up to three more optional, all rendered in a single viewer with a mode switch. No outputs - it's a terminal node, its entire job is showing you things.

It's part of ComfyUI-GeometryPack ("ComfyUI libigl") by Andrea Pozzetti. If you've seen Preview Mesh Dual, this is the same idea with the ceiling raised from two to four inputs. The one-mesh baseline is the plain Preview Mesh; this one is for the "which of these do I actually like" moment.

How it works

The inputs are just the meshes - mesh_1 (required), mesh_2, mesh_3, mesh_4 (all optional TRIMESH) - plus a mode combo:

• fields (default) - the scientific-visualization mode. Meshes carrying scalar fields (curvature from ParaView Filter, distances from the distance nodes, whatever) render with their field data colorized.
• texture - textured rendering, for when the meshes have real materials and you want to see the surface as it would actually look.

Like its dual sibling, the multi viewer handles common fields across the loaded meshes, so you're not stuck comparing self-scaled color ramps when every mesh has the same attribute.

The practical shape of it: load a folder of variations, wire four of them in, and flip through how they differ at a glance. It's also a genuinely good sanity node for batch work - stick it after Load Mesh Batch output a handful of meshes to confirm the loader actually brought in what you think it did.

Where it's the right tool

• Comparing a decimation ladder - the same mesh at four different triangle counts, side by side, so the quality cliff is visible instead of abstract.
• Reconstruction variants - four outputs from a generator you're evaluating, in one pane.
• Debugging a batch - confirm the first four items of a batch look right before you commit to processing all of them.

Install and caveats

Same as the rest of the pack: search "GeometryPack" in ComfyUI Manager, or:

cd ComfyUI/custom_nodes
git clone https://github.com/PozzettiAndrea/ComfyUI-GeometryPack.git
cd ComfyUI-GeometryPack
pip install -r requirements.txt --upgrade
python install.py

Restart after. The pack's comfy-env installer (with pixi) provisions a heavy isolated environment - Blender, CGAL, libigl, VTK - and copies the viewers into place at startup, so first launch is slow and a missing/blank widget after an update is a restart-first problem, not a reinstall-first one.

The honest limitations: four viewports in one widget means each pane is smaller, so this is for overview, not fine inspection - if you need to study one mesh in detail, split it out to the plain viewer. And fields-only or texture-only is per-mode, not per-mesh; you can't have two textured and two fields in the same run. That's a minor constraint, but it bites if you were hoping to mix. The pack is WIP with fast releases, so viewer behavior can shift between versions - when in doubt, restart and re-check.