Node Peek

Store fields

Description (Markdown body)

See what every node does — without plugging it into the output.

Node Peek renders a small thumbnail above each node in the Shader Editor, showing that node's actual output. Textures, ramps, math, mixes, and full BSDFs all get a live preview, so you can read a material at a glance instead of rewiring it to the Material Output over and over.

Features

• A preview on (almost) every node — texture, colour and vector nodes show a flat 2D map; shader nodes show a lit sphere.
• Live updates — tweak a value and the affected previews refresh on their own.
• Never blocks Blender — previews are rendered in a separate background process, so the interface stays responsive even on heavy graphs.
• Doesn't touch your file — nothing is written into your .blend; open your scene anywhere, with or without the add-on.
• Smart caching — only nodes that actually changed re-render; results are reused across undo/redo and reverted tweaks.
• Node-group aware — step into a group and its interior gets previews too, evaluated with that instance's real inputs.
• Light on resources — thumbnails render at 1 sample where possible, on a capped number of threads, at low process priority.

How it works

When your material changes, Node Peek hands a copy of just that material to a persistent background Blender running in --background mode. It renders each changed node's output to a small image, which the add-on then draws above the node with the GPU. Your actual scene is never modified and never re-rendered.

Usage

1. Open a Shader Editor and select an object with a node-based material.
2. Previews appear above the nodes automatically.
3. Open the N-panel → Node Peek for controls (resolution, refresh, clear).
4. Prefer to choose nodes yourself? Turn off Previews Visible By Default and press Ctrl+Shift+P to toggle previews on the selected nodes.

Requirements

• Blender 4.2 or newer.
• Previews render with Cycles in the background process (this is reliable headless; EEVEE is available as an experimental option but often renders black without a GPU context).

Good to know

• Previews render the surface shader. A material driven by the Material Output Displacement input shows its bump/normal detail but not the displaced silhouette.
• Repainting a packed image doesn't auto-invalidate its preview — use Refresh Previews.
• The view transform is fixed to Standard, so previews don't match an AgX/Filmic look.

Open source

GPL-3.0-or-later. Source, issues and contributions: https://github.com/mlstr0m/node-peek

Built by mlstr0m — Résidence Principale.

Independent, clean-room implementation inspired by the idea behind the commercial "Node Preview" add-on. It shares none of that product's code.