A drawing is a record,
not a picture.
The drawings handler reads a sheet as the document it is: geometry on the layers it belongs to, the title block that dates it, the dimensions that quantify it, and every annotation written on it — all of it citable, none of it flattened.
LLX-HANDLER-DRW · R3 · 10 formats
Four things a picture cannot give you.
Sheet and title block
Sheet number, revision, scale, discipline and issue date are read as fields. A sheet can be placed in the chronology on its own metadata.
Geometry and layers
Entities are read with the layer they sit on, so an addition can be attributed to a discipline rather than described as “a change to the drawing”.
Annotations and dimensions
Text, leaders, dimension strings and revision clouds become passages you can cite, with their coordinate on the sheet.
Model structure
For IFC and native model files, the object tree is read: element type, storey, and the properties attached to each object.
The questions drawings usually decide.
What changed between revisions
Two revisions of one sheet are compared entity by entity: added, moved, removed. The answer is a list, not an impression.
Revision diffWhen an instruction reached the drawing
A revision cloud carries a date. Matched against the correspondence, it shows when a change was drawn against when it was instructed.
ChronologyWhether the built work follows the issued sheet
Dimensions and annotations are read as values, so the sheet can be checked against records of what was built.
QuantumRead in place, in the format it arrived in.
The file is never converted, flattened or re-saved. It is read where it lies, and the handler records a SHA-512 of the bytes it read — so a passage cited from a drawing today can be replayed against the same file years from now.