Skip to content

Observation Overrides

Observation overrides let you record legal plan dimensions (bearings, distances, and observation metadata) that differ from the drawn geometry. When R3Survey exports a NSW LandXML file, overrides take priority over computed values.

Common reasons for overrides:

  • Adopted dimensions from an earlier plan (e.g. an existing boundary from DP 123456)
  • Compiled or calculated dimensions on a compiled plan
  • Legal bearings/distances that differ slightly from the coordinate geometry after adjustment
  • Recording the accuracy class, adoption source, or field notes for a segment

Setting overrides in R3PROPERTIES

Select a line or polyline on a survey plan layer. Two expanders in R3PROPERTIES are used for overrides:

  • Dimension Overrides — for legal bearing, distance, arc length, and radius values
  • Survey Method — for the observation derivation method, adopted survey reference, and field notes

For polylines, use the Current Leg selector to navigate to the segment you want to override. Each segment stores its overrides independently.

Dimension Override fields

Field Description XData key
Legal Brg Legal bearing (overrides computed bearing) Azimuth
Legal Dist Legal horizontal distance (overrides computed distance) HorizDistance
Legal Arc Len Legal arc length (arc segments only) ArcLength
Legal Radius Legal radius (arc segments only) Radius

Survey Method fields

Field Description XData key
Method How the measurement was obtained — sets both distance and bearing type DistanceType, AzimuthType
Adopted Plan number the dimension was adopted from AdoptedSurvey
Note Field note text FieldNote

The Line State field (Found, Placed, or Found By Me) is in the Reference Mark expander — it maps to distanceAccClass in the LandXML and only applies to reference mark connections.

Method values

The Method dropdown includes:

Measured, Adopted, Calculated, Deducted, Scaled, Compiled, GNSS, LRSCalculated, Cadastral Traverse, AUSPOS, Static GNSS, RTK GNSS, CORS NRTK GNSS, CORS RTK GNSS, CORS Static GNSS

When you select a method, R3Survey sets both distanceType and azimuthType to the same value. This matches standard practice — it's rare for the bearing and distance of a single line to have different derivation methods.

Note

If the survey plan's Survey Type is set to compiled, all observations default to Compiled type in the export. If set to surveyed, the default is Measured. Per-segment overrides take priority over these defaults.

Per-segment storage

On polylines, overrides are stored with the key pattern Leg.{index}.{key} (e.g. Leg.0.Azimuth, Leg.2.HorizDistance). The segment index is 0-based.

On standalone lines (reference marks, connections), overrides use the bare key name (e.g. Azimuth, HorizDistance).

R3SHOWOVERRIDES — Highlight overridden segments

Command: R3SHOWOVERRIDES

Draws magenta highlight lines over every segment in a plan that has any observation override set. Use this for a quick visual check of which segments have been overridden.

Usage

  1. Type R3SHOWOVERRIDES
  2. If the drawing has multiple plans, select the plan to check
  3. R3Survey draws magenta highlights on the non-plottable R3_OVERRIDES layer

The highlights remain visible until cleared with R3HIDEOVERRIDES.

Note

The R3_OVERRIDES layer is non-plottable — highlights will not appear on printed output.

R3HIDEOVERRIDES — Clear override highlights

Command: R3HIDEOVERRIDES

Removes all override highlight entities drawn by R3SHOWOVERRIDES.

Usage

  1. Type R3HIDEOVERRIDES
  2. All entities on the R3_OVERRIDES layer are erased

R3CHECKOVERRIDES — Override report dialog

Command: R3CHECKOVERRIDES

Opens a modeless report dialog listing all observation overrides in the plan, with warnings for potential issues.

Usage

  1. Type R3CHECKOVERRIDES
  2. If the drawing has multiple plans, select the plan to check
  3. The Observation Overrides dialog opens

Report contents

The report lists two types of entries:

Type Description
Override A segment with one or more override values set. Shows the override value alongside the computed geometry for comparison (e.g. Dist: 25.450 (geom: 25.453))
WARNING A shared boundary segment where one lot has overrides but the adjacent lot does not. This can cause unexpected values in the exported file

Each row shows the entry type, parcel name, segment number, and override details.

  • Double-click a row to zoom the AutoCAD viewport to that segment
  • Right-click a row for options:
    • Zoom To Segment — centres the view on the segment
    • Refresh — rescans the drawing for changes

The dialog auto-refreshes after most AutoCAD commands (except zoom, pan, and regen).

Shared boundary warnings

When two adjacent lots share a boundary segment, R3Survey exports only one observation for that physical boundary. If one lot has overrides on the shared segment but the other does not, the report flags this as a warning — the override from one lot will be used, but it may not be what was intended.

To resolve: set matching overrides on both sides, or clear the override from the unintended side.

How overrides affect the export

When R3EXPORTLANDXMLNSW builds observations:

  1. For each segment, it checks for per-segment override XData
  2. If an override exists for bearing or distance, the override value is used in the ReducedObservation instead of the computed geometry
  3. Observation type attributes (distanceType, azimuthType, arcType) are written only when they differ from the plan default (Measured for surveyed plans, Compiled for compiled plans)
  4. adoptedDistanceSurvey is written when the Adopted field is set
  5. distanceAdoptionFactor (combined scale factor) is written when set on line observations
  6. FieldNote is written as a child element when the Note field is set

Shared boundary deduplication

When two lots share a boundary segment, both polylines contain that segment. The exporter deduplicates by matching SetupID/TargetSetupID pairs (checking both directions). When duplicates are found, the version with overrides is preferred over the undecorated version.

This means overrides only need to be set on one side of a shared boundary — but using R3CHECKOVERRIDES to verify consistency is recommended.

See also