Three Grid Helper

Before you light and texture anything, you need to know where things are - and a floating model on a blank background gives you no sense of scale, height or depth. Three Grid Helper lays a flat grid on the ground plane, giving you a horizon and a unit ruler to judge the camera against. It's the draughting-table node of the Three suite, and it's the difference between fighting an invisible camera and seeing at a glance that your subject is floating six units up.

It's a guide, not part of the model. The grid takes no light and casts no shadow, so it never changes how the scene is lit - you can leave it in for a technical look or pull it before the final render. It sits on the ground plane at the origin (y = 0), so if your floor lives somewhere else, run it through Three Transform Object like any other object. Wire it into a group beside your meshes (or straight onto Three Scene's root) and use it to set the camera's height and target before you commit to the pretty stuff.

The dials are self-explanatory. size is how far the grid reaches edge to edge in scene units (10.0 suits a unit-sized subject). divisions is how many cells across - 10 divisions in a 10-unit grid gives you one-unit cells, which is the most useful setup for judging distances. center_color and grid_color are hex for the two lines through the origin and the rest of the lines respectively; mid-grey for the centre and a darker grey for the field is the sane default, and it keeps the grid readable without shouting over your scene.

The one real skill here is using it as a scale reference, not decoration. Drop a unit cube on the grid first, then look at the grid cell size relative to the cube - that calibration moment tells you whether your scene is set in metres, centimetres or something you invented. Everything else in the scene, from light panel sizes to the area light's soft-shadow behaviour, depends on that mental unit model. Get the grid up first and the rest of the scene stops being guesswork.

Because it's technically a THREE_OBJECT, it composes with everything that takes one: hide it by putting it in a group and flipping visible off when you're done framing, or keep it and embrace the isometric-technical look.

Installing it

Part of WAS Node Suite v3. ComfyUI Manager: search WAS Node Suite v3, or:

cd ComfyUI/custom_nodes
git clone https://github.com/WASasquatch/was-node-suite-comfyui.git

Restart; needs ComfyUI 0.14.0+ / Python 3.10+. Nothing installs. If the Three menu's missing, set features.threejs: true in <ComfyUI user dir>/was-node-suite/config.yaml.

If it looks wrong

A grid that's invisible from your camera angle usually means you're looking edge-on or from below the ground plane - check the camera's Y position and target. And if the grid dominates your render, remember it doesn't have to stay: it's a helper, and pulling the wire before capture is a normal part of the workflow.