Preview3D_motorway_edition

This is the Preview3D node from ComfyUI core, rebadged for the Motorway pack. Its job is one thing: load a 3D model file and render it in an interactive viewer in the browser so you can orbit, zoom, and inspect it. If your workflow generates or edits GLB/glTF assets, this is how you actually look at the result.

What makes the _motorway_edition version unusual is how thin the wrapper is. Preview3D is an output node - it has no data outputs at all, just a viewer. So there's nothing to rewire onto the bus except the bus itself. You feed it the MOTORWAY 🚌💨, it shows its model, and hands the bus back so your chain can keep going.

The widgets

• model_file - a path to the .glb or .gltf file. Relative paths resolve against ComfyUI's input folder, so models/thing.glb means the file lives in ComfyUI/input/models/thing.glb.
• material - how the model is shaded: original, normal, wireframe, or depth. Wireframe and depth are surprisingly useful for checking topology and geometry issues on 3D-generation output.
• up_direction - which axis is "up" (original, -x, +x, -y, +y, -z, +z). If your model loads sideways or upside down, this fixes the view without touching the file.

There's no INPUT_*_key here because the original node takes only widget inputs - there's no image, latent, or conditioning to fetch from the bus. The MOTORWAY 🚌💨 input is optional, so the node can sit at the end of a bus chain or even start one.

Install

The Motorway pack is pure Python with no dependencies and no bundled models:

cd ComfyUI/custom_nodes
git clone https://github.com/agilly1989/ComfyUI_agilly1989_motorway

Or install via ComfyUI Manager under the pack title ComfyUI_agilly1989_motorway, then restart.

The honest part

Let's be straight about the value proposition. Preview3D's viewer is a browser-side WebGL thing, and if you've used it you know it's more "check the mesh" than "marvel at the render." For a quick look it's fine; for judging final quality you'd export and open in a real viewer. This motorway edition adds a bus hand-off to that. If you're not already building your whole workflow on the Motorway bus, the stock Preview3D gives you the identical viewer with fewer moving parts.

The pack itself is a beta project - the README warns "IF THINGS BREAK ITS BECAUSE I BROKE IT" - and the _motorway_edition clones were auto-generated by a cloner that the 1.1.7 build disabled. Install the current version and this node may be absent from your menu; the core Preview3D won't be. And if you do hit KeyError: 'hash_...' doesn't exist in motorway somewhere downstream, remember it's a key-name mismatch on the bus, not a 3D problem - the viewer has no data dependencies of its own.