Auxiliary View Indicators

from pathlib import Path
from dessia_drawing.core import Drawing
from drawing_tools.config.default_language_configs import DEFAULT_ENGLISH_CONFIG, DEFAULT_FRENCH_CONFIG
from drawing_tools.featured_drawing import FeaturedDrawing

_DATA_DIR = Path("data/json")
drawing = Drawing.from_json(str(_DATA_DIR / "condor/condor_BEAM_ASSY.json"))
featured_drawing = FeaturedDrawing(drawing, language_configs=[DEFAULT_FRENCH_CONFIG, DEFAULT_ENGLISH_CONFIG])
featured_sheet = featured_drawing.sheets[1]
featured_view = featured_sheet.views[0]

featured_view.plot_data_auxiliary_view_indicators().plot()
featured_sheet.plot_data_auxiliary_view_indicators().plot()
featured_view.plot_data_all_identifiers().plot()
featured_sheet.plot_data_all_identifiers().plot()

Auxiliary view indicators are TypeNote annotations with letter F and a nearby FillArrow that are not part of a detected view title or section line indicator. They represent auxiliary view references (renvois de vues auxiliaires) — labels pointing toward where an auxiliary view (“VUE SUIVANT F…”) is taken.

See also

For the related section line indicator detection, see Section Line Indicators. For a working example combining both features, see scripts/section_lines_and_auxiliary_view_indicators.py.

What is an Auxiliary View Indicator?

On a technical drawing, when an auxiliary view is defined elsewhere, a label with a FillArrow is placed on the parent view to indicate the viewing direction. For example:

• "F3" — reference to auxiliary view F3 (same sheet, no cross-reference)

• "F1 2/3" — reference to view F1, defined on sheet 2 of 3

• "F2 2/3" — reference to view F2, defined on sheet 2 of 3

Detection requires two conditions beyond the identifier pattern match:

1. Letter F — the identifier letter must be "F"

2. Nearby FillArrow — a FillArrow leader must be attached to or near the annotation

To see the code behind these conditions, see Going Further at the end of this page.

Accessing Auxiliary View Indicators

Auxiliary view indicators are detected automatically on each FeaturedView:

for sheet in featured_drawing.sheets:
    for view in sheet.views:
        for identifier_info, entity in view.auxiliary_view_indicators:
            text = entity.get_text_content().strip()
            print(f"{text!r} -> {identifier_info.to_label()}")

Each entry is a tuple of (IdentifierInfo, Entity) where:

• ``identifier_info`` has the same fields as for section line indicators (identifier, letter, number, cross_reference, etc.)

• ``entity`` is the source TypeNote annotation

View-Level Visualization

The following visualization shows auxiliary view indicators on the “VUE DE FACE” view of the BEAM ASSY drawing (Sheet 1). Three indicators are detected: F3, F1 2/3, and F2 2/3.

Source: condor_BEAM_ASSY.json, Sheet 1, VUE DE FACE

featured_view.plot_data_auxiliary_view_indicators().plot()

Sheet-Level Visualization

Auxiliary view indicators can also be visualized at the sheet level:

Source: condor_BEAM_ASSY.json, Sheet 1

featured_sheet.plot_data_auxiliary_view_indicators().plot()

All Identifiers Combined

The plot_data_all_identifiers method combines overlays from all three identifier sources: view titles, section line indicators, and auxiliary view indicators.

Source: condor_BEAM_ASSY.json, Sheet 1, VUE DE FACE

featured_view.plot_data_all_identifiers().plot()

Source: condor_BEAM_ASSY.json, Sheet 1

featured_sheet.plot_data_all_identifiers().plot()

Going Further: Inside the Detection

For readers who want to see how the detector works

This feature has no class of its own: an indicator is a pair (IdentifierInfo, Entity) — the parsed identifier (view/identifier_info.py) and the TypeNote carrying it — and the recipe is the FeaturedView property itself (view/featured_view.py). FeaturedSheet.auxiliary_view_indicators concatenates the views’ results.

@cached_property
def auxiliary_view_indicators(self) -> list[tuple[IdentifierInfo, Entity]]:
    """Detect auxiliary view indicator annotations (renvois de vues auxiliaires).

    Returns TypeNotes matching the identifier pattern with letter ``"F"`` and
    a nearby FillArrow, that are **not** part of any title or section line
    indicator. These represent auxiliary view references (e.g., ``"F2 2/3"``,
    ``"F3"``), typically labeled "VUE SUIVANT F..." on the target view.

    :return: List of (IdentifierInfo, Entity) tuples for each auxiliary view indicator.
    """
    results: list[tuple[IdentifierInfo, Entity]] = []
    for note in self.notes:
        identifier_info = self._match_auxiliary_identifier(note)
        if identifier_info is None:
            continue
        if not self._has_nearby_arrow(note):
            continue
        results.append((identifier_info, note))
    return results

The two guards are the two conditions of What is an Auxiliary View Indicator?:

• _match_auxiliary_identifier skips the notes already claimed by the view title or a section line indicator (_excluded_entity_ids), parses the text with match_text_against_pattern and DEFAULT_INDICATOR_PATTERN, and keeps the letter AUXILIARY_VIEW_LETTER only;

• _has_nearby_arrow (has_nearby_arrow in view/annotations/composite_arrows.py) asks for a FillArrow leader on the note or a CompositeEntity arrow drawn next to it — the same arrow collection the section line detector uses.