Fixing a 3D model that imported without a CRS offset
When you import a 3D model (such as a BIM or CAD model), Pointerra checks that the model's coordinates make sense for the coordinate system you selected. If the model imports successfully but all of its coordinates sit very close to zero (the "origin"), Pointerra shows a warning. This usually means the model has not been placed in its correct real-world location.
This article explains what the warning means and how to fix it.
The warning you'll see
On the dataset's details page, the Status field shows a yellow warning:
Warning: Model source coordinates are close to the origin without a CRS offset. The model may be geolocated incorrectly.
Click Warning details to see more, including the model's origin coordinates. For example:
Model source coordinates are close to the origin without a CRS offset. The model may be geolocated incorrectly.: Model origin: -0.568275, -0.899601, -49.205705
Your model still imported. This is a warning, not an error, but the model may be in the wrong place.
What this means
Every 3D model is built in some coordinate system. Many models, especially BIM and CAD models, are created in a local coordinate space, where coordinates are measured relative to a local origin point (for example, a corner of a building site) rather than to true real-world coordinates. In a local coordinate space the numbers are small and centred around zero.
When Pointerra sees that all of your model's coordinates are bunched up close to (0, 0, 0), as in the example above, it is a strong sign that the model is still in its local coordinate space and has not been shifted to its real-world position. Without that shift, Pointerra does not know where on Earth the model belongs, so it may appear in the wrong place or far away from the rest of your project data.
How to fix it: add a CRS offset
To place the model correctly, you need to tell Pointerra the offset between the model's local coordinates and its real-world coordinates. This is called the CRS offset. Pointerra adds this offset to every coordinate in the model, shifting the whole model from its local origin to its correct position in the coordinate system you have chosen.
The offset is the real-world location of the model's local origin, written as three numbers: x, y and z (for example, easting, northing and height).
Where to find the offset value
You will not usually find this value in Pointerra. It comes from whoever produced or exported the model. When a model is exported into a local coordinate space, a fixed amount is subtracted from every coordinate so the numbers stay small. The CRS offset is that same amount, added back on. Ask the person or software that produced the model for:
the model's base point, survey point or global origin, or
the
x,y,zvalues that were subtracted when the model was exported.
They should be able to provide these, along with the coordinate system the values are in.
Reprocess the dataset with the offset
Once you know the offset, reprocess the dataset to apply it:
Open the dataset's details page and click Re-process.
In the Configure Dataset window, scroll down to the Coordinate reference system section.
Expand Let me select from a list of coordinate systems and choose the coordinate system your offset values are in.
In the CRS offset (Advanced) field, enter your offset as three comma-separated numbers in
x,y,zorder. For example:500000,7000000,100.Click Save to begin reprocessing.
Pointerra will reprocess the model and place it at its correct real-world location. Once
reprocessing finishes, the Coordinate Reference System section on the dataset details
page will show the Offset you entered, and the warning will no longer appear.
Tip: The offset must be in the same coordinate system you select in step 3. If the model still appears in the wrong place after reprocessing, check that the coordinate system and the offset values match the information from your data provider, and that the values are in
x,y,zorder.
What if my model isn't meant to be geolocated?
Some 3D models have no real-world location at all. They are standalone objects that are not tied to a place on the globe. In that case you do not need a CRS offset. Instead, when you upload the dataset, choose the My data is not georeferenced option.