De Boor at t = k/256 with the Bezier path's lerps. Each blending factor
(t - knot) / span is quantized in 1/256 from the nearer of its two knots,
and a segment's last point is evaluated as the next one's first. Colors,
texture coordinates, generated UVs and normals work as for Bezier
patches. Bit exact on gpu/probe exp144-146; software renderer only.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>