Surfaces
Blender add-on v0.1.1
Review notes for the people building the scene, right inside Blender. A Red Pen tab in the 3D Viewport sidebar lets you leave typed, status-tracked notes that live in a sidecar file next to the .blend - never inside it - and push to the Red Pen Hub so they land on the same board as your WordPress, Express, and static notes.
What it is
Red Pen for Blender is a Blender 4.2+ extension (the sixth surface in the family). It adds a Red Pen tab to the 3D Viewport's N-panel where you create and work through review notes. It is the 3D-tool sibling of the static drop-in and the Express middleware: the same overlay idea and the same note fields, with a file-based backend that the Hub already understands.
One thing it deliberately does not do: it never creates objects in your scene and never writes notes into the .blend. The on-screen list is a runtime mirror; the real notes live in a separate sidecar file. Open the .blend without the add-on and the file is clean - no stray note objects, nothing in your renders.
Install
The add-on is distributed as a versioned extension zip (under releases/ in the project).
- In Blender, open Edit > Preferences > Get Extensions > Install from Disk.
- Pick the release zip, for example
red_pen-0.1.0.zip. - Enable Red Pen for Blender.
To roll between versions, Install-from-Disk a different zip from releases/ - Blender replaces the installed copy with that build.
Using it
Press N in the 3D Viewport to open the sidebar, then click the Red Pen tab. From there you can:
- Add a note. Type the note text, choose a type - Note, Bug, To-do, or Question - and click Add. See Core concepts for what the fields mean.
- Work the list. Every note for the current file shows with a status icon and a type icon. Select one and use Resolve, Reopen, or delete.
- Refresh. Re-read the notes from disk - handy after a resolve was pushed back from the Hub, or after editing the sidecar by hand.
The panel's status box tells you where notes are being saved: the project sidecar when the .blend is saved, or a scratch file with a warning when it is not.
Where notes are stored
Notes are written to a JSON sidecar - the same .redpen/notes.json store the Hub folder-scans for the Express and static surfaces - so the Blender surface drops straight into the existing pipeline.
| Situation | Where notes go |
|---|---|
| Saved .blend | <your-project>/.redpen/notes.json, next to the .blend. This is the file the Hub can folder-scan. |
| Unsaved .blend | ~/.red-pen-blender/scratch.json - a fallback so notes are not lost before the first save. A push still works; save the .blend to move notes into the project sidecar. |
The sidecar is the single source of truth. The list you see in the panel is a runtime copy held on Blender's Window Manager, which is never saved into the .blend - that is how the notes stay out of your scene file.
Connect to the Hub
The add-on can push its notes to the Red Pen Hub so they appear on the combined board next to every other project, tagged with the blender surface. To set it up:
- Start the Hub (it serves
http://localhost:3900). - Get the Hub's connect token: open
http://localhost:3900/api/connect-infoin a browser. - In Blender, open Edit > Preferences > Add-ons > Red Pen for Blender and paste the Hub URL and Connect Token. Optionally set a Project name (it defaults to the .blend filename).
- Back in the N-panel, click Push. The project self-registers as a connected source - there is no separate "add source" step.
Turn on Auto-push on change in preferences if you want every add, resolve, or delete to push automatically. The push is a localhost call, so it works whether or not Blender's Online Access toggle is on. See the Hub page for how connected sources and the URL and token work.
The round-trip: resolving from the Hub
Push sends notes up; Pull brings changes back down. A connected push store is one-way by design - resolving a note on the board updates the Hub's own copy, not the file in Blender - so the Pull button is what closes the loop. Click it and any note you resolved or reopened on the board is applied to this file's notes (matched by id).
A simple rule keeps the two directions from fighting: pull before you push if you have resolved notes on the board. Otherwise a push of stale local state could overwrite a Hub-side resolve. (A single merge-aware Sync button is planned; for now the two buttons keep the behaviour explicit.)
Current status
Version 0.1.1 ships the Red Pen N-panel tab, typed notes (Note / Bug / To-do / Question) with an open / resolved status, a per-file list with resolve / reopen / delete, the .redpen/notes.json sidecar with the unsaved-file scratch fallback, and Push / Pull with the Hub (the pull completes the round-trip so board-side resolves reflect in Blender). It creates no scene objects and writes nothing into the .blend.
Planned next (0.2.0): pinning a note to an object, face, node, or render frame using Blender's gizmo system - so a pin occludes behind geometry and is clickable - plus an in-progress status and threaded replies. Progress is tracked on the Roadmap.