This guide helps you select the correct coordinate system for your work in IVION, whether you’re setting up a site, importing data, or exporting it to another application. It explains how site coordinates, spatial reference systems, and dataset coordinates differ, and when to use each option. You’ll also learn how units, the site base point, elevation, and transformations affect your choice, which limitations apply to your workflow, and how to check that your data is positioned and scaled correctly.
1. Identify your project's coordinate reference
Identify the coordinate reference your data already uses or the receiving project requires. For an import, use the incoming file's coordinate reference. For an export, use the coordinate reference required by the receiving application.
Your task | Coordinate decision |
|---|---|
Set up a site | Define the site base point and location reference so the site's location is consistent with the data you plan to add. |
Process surveyed scan data | Use the coordinate system and units of the surveyed control points. Keep control points for the project in the same reference. |
Export measurements or a point cloud | Select site coordinates, a supported spatial reference system, or the coordinate system of a specific dataset to match the receiving project. |
Export an orthophoto | Select site coordinates or a supported spatial reference system for the image metadata. Dataset coordinates are not available. |
Import a DXF vector map | Identify the coordinate system already used by the file, or a defined custom transformation that relates it to the site. |
Import an IFC model | Use the model's supported coordinate information, or another placement method provided by 3D Model Management. |
Connect a Revit project | Use an existing transformation if the references already match, or create a transformation from corresponding tie points. |
Follow these steps to find your project reference:
Check the survey information, file metadata, or project settings for the coordinate system name or EPSG code. If it is not specified, confirm it with the project owner.
Record the units, origin, axis order, orientation, and elevation reference. For a local project, identify how its coordinates relate to the IVION site or a specific dataset.
Use this information to choose the IVION coordinate option in the next section.
2. Choose the IVION coordinate option
Use your project reference to choose from site coordinates, a spatial reference system, and dataset coordinates. A coordinate system defines how values describe a location. The following options refer to different references, so they are not interchangeable.
Reference | What it means in IVION | When to use it |
|---|---|---|
Site coordinate system | The common local coordinate system for an IVION site. The site base point is its origin, (0, 0, 0). Alignment places datasets in this shared reference. | Use it when your project or reference data uses the IVION site's coordinates. |
Spatial reference system | A defined geographic or projected reference system. You can search for supported systems by name or EPSG code. A projected system uses coordinates such as easting, northing, and height; geographic coordinates describe location using latitude and longitude. | Use the system specified for your surveyed control points or the data you exchange with another application. Check that the feature supports that system and its units. |
Dataset coordinate system | The coordinate reference of a selected dataset. It is distinct from the site's shared coordinate reference; a dataset transformation relates the two. | Use it when you need to export data in the selected dataset's coordinate system, for example to match data referenced to that dataset. |
Local coordinates and georeferenced coordinates
A local reference uses an origin chosen for the project or dataset. Georeferenced data has a defined relationship to a real-world reference system. A site can use local coordinates while its base point and rotation relate those coordinates to a real-world location.
Knowing where a building appears on a map does not by itself verify its surveyed position. When your project requires a known survey reference, use the appropriate surveyed control points and verify the result.
EPSG codes, WGS 84, and projected systems
An EPSG code identifies a coordinate reference system. Use the code supplied with your survey or project data to distinguish systems that have similar names.
WGS 84 latitude and longitude describe geographic location. Projected systems provide planar coordinates for a defined area. For example, EPSG:25832 identifies ETRS89 / UTM zone 32N. Choose the reference required by the project, including its zone and datum, rather than choosing a system only because it covers the same region.
Support depends on the IVION feature. Being able to set a site's location with latitude and longitude does not mean every import or export accepts geographic coordinates.
How site settings, alignment, and transformations affect your choice
Site base point, rotation, and elevation
The base point and rotation relate the site's local coordinates to its location. The base point's Z/Height defines how you interpret the site's zero-elevation reference.
Base point and rotation
The site base point defines the origin of the site coordinate system. Depending on the location reference, its position is entered as latitude and longitude or projected coordinates, with a height value. Rotation defines the orientation of the site's local axes relative to that reference.
To inspect or change these settings, click Edit site to enter Draft Mode, then go to Settings > Edit Site Location > Show advanced settings. Follow Editing a Site Location for the procedure, or Adding a Site when creating a site.
Elevation and changes to the base point
The base point's Z/Height defines the site's zero-elevation reference for georeferencing. Changing it does not change the values stored in a surveyed control point file or update datasets that have already been processed.
Changing the base point's Z/Height does not change local site Z coordinates. It can change the height values exported in a spatial reference system. If you need to change surveyed coordinate values in the processed data, correct the control point data and follow Control Point File Requirements and Formats for IVION Processing.
Alignment and georeferencing
Alignment places datasets or models relative to each other. Georeferencing relates data to a known real-world coordinate reference. These serve different purposes, even when both are part of the same workflow.
Dataset alignment
IVION uses a transformation to place each dataset in the common site coordinate system. You can then display datasets with different coordinate references together.
Cross-Dataset Alignment (CDA) can align datasets using surveyed control points or alignment markers. Alignment markers without surveyed coordinates help stitch datasets together; they do not establish a surveyed coordinate reference. See Control Point Types: Surveyed and Alignment Markers and Aligning Datasets for the workflows and verification methods.
Surveyed control points
Surveyed control points provide known coordinates for processing and verification. They can use an arbitrary local system or a georeferenced system. Keep control points in the same project in the same reference.
IVION Processing requires metric values in a right-handed coordinate system. For local coordinates, keep the origin near the scanned site. IVION requires site data to be within 20,000 m of the site base point. See Control Point File Requirements and Formats for IVION Processing for file structure and the remaining processing requirements.
Custom transformations and Revit
A custom transformation defines how one coordinate reference relates to another through translation and rotation. Use a known transformation when a drawing or model has its own local reference.
For vector maps, IVION provides Manage transformations to define a reference relative to the site or a spatial reference system. See Working with .dxf Vector Maps for the procedure.
The Revit add-in can use an existing transformation or calculate one from corresponding tie points in the IVION site and Revit model. Check the floor heights and corresponding locations before applying it. See IVION Add-In for Autodesk® Revit.
3. Check the limits for your workflow
Coordinate support varies by feature and format. Use the following table to check the relevant limit before exchanging data.
Feature | Coordinate behavior or limitation | Procedure |
|---|---|---|
Measurement export | CSV and DXF exports offer Site coordinate system, Spatial reference system, and Dataset. A saved custom transformation can also appear under Other. For exports using Site coordinate system, the account unit setting changes CSV measurement values and their unit labels, while CSV coordinates remain in meters. DXF geometry coordinates and unit metadata follow the metric or imperial account setting. Check the units when opening the output in your CAD application. | |
Point cloud export | Crop & download preserves georeferencing in the selected reference. For an imperial (foot-based) coordinate system, use RCS or LAS. These point cloud formats support imperial coordinate systems. | |
Orthophoto export | The selected coordinate reference is written to the TIFF metadata. Dataset coordinates are not available. The receiving application must interpret the metadata correctly; check image scale and placement. | |
DXF vector map import | Select the source coordinate system of the file. Local coordinate values must be metric. This requirement applies to DXF import. It doesn't apply to measurement export. | |
IFC model import | For IFC model placement using embedded coordinate information, IVION supports projected coordinate systems with metric units. Geographic systems such as WGS 84 (EPSG:4326) and projected systems using feet are not supported for this placement method. | |
Site location | The site location reference and base point must be consistent with the processed data. Datasets must be within 20,000 m (20 km) of the site base point to be added to the site. |
Changing the account unit setting is separate from defining a coordinate reference. For example, choosing feet as the account unit setting does not identify an EPSG code, project origin, or elevation reference.
Follow the linked feature procedure to apply your choice. Keep the coordinate reference and units consistent with the project information you identified in section 1.
4. Verify the result
Use known reference data to confirm that the transferred data is correctly positioned and scaled. A matching coordinate system name does not replace a check of the result.
Compare a known distance to confirm scale and units.
Compare known reference points to check horizontal position and orientation.
Check elevation against the project's height reference, especially when combining separately surveyed areas or models.
Check that the receiving application used the file's coordinate information. If it needs a manual placement or import setting, follow that application's procedure.
If IVION reports that a dataset is too far from the site, compare the site's location reference with the control point file and processing quality report. Check coordinate order as well as the reference system.
5. Use coordinates through the API
Integrations must account for the distinction between dataset coordinates and site coordinates. Use the dataset's transformation when combining streamed points from different datasets.
For streamed point clouds, first decode the point positions and apply the scale and offset needed to obtain dataset coordinates, then apply the dataset-to-site transformation. See Point Streaming API Usage Guide for the API contract and processing order.