oas-geometry

Original：🇺🇸 English

Translated

Use when writing or debugging OAS geometry — points, polygons, line segments, arcs, circles, spirals, fillets, units, or coordinate conventions. Load before any geometry-heavy edit.

3installs

Sourceautodesk-platform-services/open-architecture-standards-2d-floor-plans

Added on2026-06-02

NPX Install

npx skill4agent add autodesk-platform-services/open-architecture-standards-2d-floor-plans oas-geometry

SKILL.md Content

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OAS Geometry

When to use

Use this skill whenever the task touches coordinates, curves, polygon validity, units, or angular conventions. This is the largest section of the spec, so load it early when you suspect a geometry bug (integer-mm violations, polygon not closing, arc winding wrong). If the work is about which entity owns the geometry (room vs. wall etc.), prefer

oas-core

or

oas-layout

.

Key types

```
Point
```
—
```
{ x, y }
```
in integer mm (optionally
```
z
```
for railings on stairs)
```
Polygon
```
— ordered
```
points
```
array plus explicit
```
"closed": true
```
;
```
closed: false
```
is allowed for open paths (e.g. railings)
```
LineSegment
```
— straight edge from
```
start
```
to
```
end
```

Arc

— circular arc with

center

,

radius_mm

,

start_angle_deg

,

end_angle_deg

```
Circle
```
— full circle (
```
center
```
,
```
radius_mm
```
)
```
Spiral
```
/
```
Fillet
```
— specialty curves used for stairs and corners

Critical rules

No decimals in coordinates. Every
```
x
```
,
```
y
```
,
```
z
```
, radius, length is integer millimeters. The single exception is
```
area_m2
```
, which is a derived decimal value in square meters.
Polygons must declare
"closed": true
explicitly. A polygon without this flag is not closed by convention — don't rely on the last point matching the first.
Consistent winding. Point order must be uniformly clockwise or counterclockwise; do not mix. Positive rotation is counterclockwise.
Arc sweep is CCW from
start_angle_deg
to
end_angle_deg
. If you want a clockwise visual arc, swap start/end — do not negate angles.
Units are global.
```
units.length
```
is
```
"mm"
```
and
```
units.angle
```
is
```
"deg"
```
for the whole document; do not introduce per-entity unit overrides.

Full schema

See docs/geometry.md for the complete reference, including arc parameterization, spiral construction, and fillet rules.

Related skills

```
oas-core
```
and
```
oas-layout
```
— consumers of these geometric primitives
```
oas-render
```
— for how these primitives map onto screen coordinates (Y typically inverts)