text-version-stamp

Text Version Stamp

A runnable example that builds a beveled 3D stamp of the running Blender version — a TextCurve (bpy.data.curves.new(type='FONT')) whose body is the live bpy.app.version_string, so every render self-documents which Blender produced it. CI artifacts made this way are self-labeling.

What it witnesses: the TextCurve data-API contract. curves.new(type='FONT') returns a Curve subclass, the built-in font ("Bfont Regular") is always loaded even headless, body is plain assignable text that regenerates geometry on edit (more characters → strictly wider evaluated mesh), and extrude / bevel_depth produce exactly predictable solids: the evaluated mesh z-extent equals 2 × (extrude + bevel_depth) and the round bevel widens the outline in-plane by 2 × bevel_depth. Flat text (no extrude, no bevel) is already filled — faces exist — but strictly planar. The check also witnesses the depsgraph lifetime hazard: after to_mesh_clear() the returned Mesh reference is dead and any access raises ReferenceError.

Version divergence: the string format itself differs — "5.1.2" on 5.x but "4.5.11 LTS" on 4.5 (the suffix is part of version_string). The check therefore asserts the contract that holds on both: version_string starts with the dotted bpy.app.version tuple. Code that parses version_string as a bare semver breaks on every LTS build; branch on the bpy.app.version tuple instead.

Staging

The numerals stand on a dark plinth, with the steel caption set into the plinth's front face. The caption used to float in the air above the stamp, and an emissive bar lay along the bottom edge of the frame. The still renders under the Standard view transform on the house stage. Render path only; the checked text body and its extents are unchanged.

Run

# Cheap correctness check (no render) — the CI check:
blender --background --python text_version_stamp.py --

# Falsifier: body is not version_string. Must exit non-zero.
blender --background --python text_version_stamp.py -- --wrong-body

# Also render a still (EEVEE on a GPU host; use --engine cycles on GPU-less hosts):
blender --background --python text_version_stamp.py -- --output stamp.png
blender --background --python text_version_stamp.py -- --output stamp.png --engine cycles

The render scales the stamp to a constant width, so the frame holds for any version-string length.

Exit codes

Per-script sequential checks. 9 is a valid check code; there is no rule against it. 10 is the shared framing helper.

Code	Meaning
0	Success
1	Uncaught exception (FATAL wrapper)
2	argparse / usage
3	Not a FONT TextCurve with the built-in Bfont
4	body is not the live version_string (--wrong-body lands here)
5	Flat text is not a filled planar mesh
6	Extrude / bevel closed form failed
7	Appending characters did not widen the text
8	Mesh survived to_mesh_clear()
9	--output produced no file
10	Gallery framing violation

The blender-smoke workflow runs the check on Blender 5.2 LTS and 4.5 LTS (5.1 on the weekly cron, the needs-5.1 PR label, or manual dispatch). Smoke does not pass --output or --wrong-body.