curve-bevel-arc

Curve Bevel Arc

A runnable example that builds a beveled Bezier semicircle entirely through the curve data API — splines.new('BEZIER'), per-point bezier_points, bevel_depth, and use_fill_caps — so the curve renders as a solid tube without a prior mesh conversion.

What it witnesses: renderable curve tubes are curve datablocks, not meshes. The check asserts eight Bezier points, bevel_depth == 0.15, use_fill_caps, and that the depsgraph-evaluated mesh has the deterministic topology (1044 verts, 1028 faces for these resolution settings) with a Z span that rests on the floor ([0, 2 × bevel]) and an X span of 2 × radius + 2 × bevel.

Run

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

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

It exits non-zero on failure (wrong point count, bevel, caps, topology, or span). The blender-smoke workflow runs the check on Blender 4.5 LTS and 5.1.

The --output render path additionally measures framing against the Layer 1 band via examples/gallery_framing.py (exit 10 on violation) before writing the still.