The 2D and 3D interpreters support draw/move, yaw, pitch, roll, turn-around,
push/pop, width, polygons, custom attributes/commands, unknown-symbol policies,
sinks, and tracing. Canonical symbols follow Appendix C, but mappings can
replace the entire alphabet.
The 3D frame stores heading, left, and up vectors. Rotations use Rodrigues'
formula and Gram-Schmidt correction, preventing uncontrolled drift. Tropism is
an injected DirectionalField; constant fields model gravity, light, or wind,
while consumer fields can depend on position and symbol state.
attachmentMappings turns non-drawing symbols into generic
OrganAttachment sockets and publishes them through GeometrySink.onAttachment.
The high-level generator supplies conventional L/K mappings from the model's
organ configuration; direct turtle consumers can map any symbol and organ kind.