Title: Discrepancies in Scale and Distance After Importing Ortho from Nubigon into AutoCAD
Message:
Hi everyone,
I’ve encountered a problem when working with Nubigon and AutoCAD, and I’d appreciate your input.
Workflow: I exported an orthophoto directly from Nubigon using the “Export Ortho” function. Then, I imported that orthophoto into AutoCAD and aligned it with features I created directly from the point cloud in Nubigon.
Problem: After importing, I noticed discrepancies in scale and distance between the orthophoto and the features. The ortho image doesn’t match the real-world dimensions I worked with in ACAD. Distances are off, and it seems the image is not aligned or scaled correctly in AutoCAD.
Possible causes I’m considering:
I’m currently using the trial version of Nubigon — could this version have limitations or export restrictions that affect scale or resolution?
Alternatively, is it simply not possible to maintain accurate scaling when exporting orthophotos this way?
Or segemented export?
Has anyone experienced similar issues or found a reliable workflow to ensure correct scaling when using orthos from Nubigon in CAD software?
Thanks in advance for your help!
0 Votes
3 Comments
Sorted by
Bert Azizogluposted
16 days ago
Admin
Orthophoto generation in NUBIGON is limited to a maximum resolution of 23170 pixels per side. Let’s assume you define the pixel size and select an export area in the viewport. If the longer side of the area divided by the pixel size exceeds the resolution limit, NUBIGON will automatically increase the pixel size to stay within the resolution limit. A high pixel size causes the inaccuracies you’ve observed.
To provide an intuitive example, an orthophoto of an entire street at the maximum resolution of 23170 pixels (=high pixel size) will have lower precision than an orthophoto of a facade at the same resolution (=low pixel size).
We recommend generating multiple overlapping orthophotos with the highest possible resolution as a solution. Check the Write TFW box to position the orthophotos in AutoCAD properly. You can also confirm the pixel size in the TFW file.
0 Votes
L
Levi Koomanposted
19 days ago
We are currently testing the Nubigon software, with a particular interest in the transformation from point cloud to orthophoto.
We are encountering several issues when importing the orthophoto into AutoCAD:
The orthophoto does not appear in the exact correct location (there is often a discrepancy of up to 5 cm, which is not accurate enough for our work — we require 1 cm or less).
The deviations between the orthophoto and the control points are not consistent in direction or distance.
The deviations are not consistent when the orthophoto is re-exported from Nubigon.
In principle, the exact same orthophoto is exported, yet each version has slightly different deviations.
The control points do match correctly within the Nubigon software (tested using a .dxf line).
Therefore, the incorrect positioning seems to occur during export.
On one occasion, the orthophoto was positioned correctly — this was when only a small portion of the point cloud was exported.
You can download a .DWG file via the following link, which contains various imported orthophotos and the visible control points.
I expect there is a solution to this issue!
Kind regards,Levi
0 Votes
Bert Azizogluposted
29 days ago
Admin
Hi Levi,
Thanks for your detailed message!
Just to clarify upfront — all orthophotos exported from NUBIGON are to scale, including when using the trial version. There are no limitations or export restrictions that would affect scaling or resolution.
If you’re seeing discrepancies after import, we recommend reviewing the steps outlined here to ensure accurate scaling and alignment in AutoCAD: How to import orthophotos into AutoCAD
Let us know how it goes! If you’re still running into issues after going through those steps, feel free to share more details — we’re happy to help you troubleshoot further!
Title: Discrepancies in Scale and Distance After Importing Ortho from Nubigon into AutoCAD
Message:
Hi everyone,
I’ve encountered a problem when working with Nubigon and AutoCAD, and I’d appreciate your input.
Workflow:
I exported an orthophoto directly from Nubigon using the “Export Ortho” function. Then, I imported that orthophoto into AutoCAD and aligned it with features I created directly from the point cloud in Nubigon.
Problem:
After importing, I noticed discrepancies in scale and distance between the orthophoto and the features. The ortho image doesn’t match the real-world dimensions I worked with in ACAD. Distances are off, and it seems the image is not aligned or scaled correctly in AutoCAD.
Possible causes I’m considering:
I’m currently using the trial version of Nubigon — could this version have limitations or export restrictions that affect scale or resolution?
Alternatively, is it simply not possible to maintain accurate scaling when exporting orthophotos this way?
Or segemented export?
Has anyone experienced similar issues or found a reliable workflow to ensure correct scaling when using orthos from Nubigon in CAD software?
Thanks in advance for your help!
0 Votes
3 Comments
Bert Azizoglu posted 16 days ago Admin
Orthophoto generation in NUBIGON is limited to a maximum resolution of 23170 pixels per side. Let’s assume you define the pixel size and select an export area in the viewport. If the longer side of the area divided by the pixel size exceeds the resolution limit, NUBIGON will automatically increase the pixel size to stay within the resolution limit. A high pixel size causes the inaccuracies you’ve observed.
To provide an intuitive example, an orthophoto of an entire street at the maximum resolution of 23170 pixels (=high pixel size) will have lower precision than an orthophoto of a facade at the same resolution (=low pixel size).
We recommend generating multiple overlapping orthophotos with the highest possible resolution as a solution. Check the Write TFW box to position the orthophotos in AutoCAD properly. You can also confirm the pixel size in the TFW file.
0 Votes
Levi Kooman posted 19 days ago
We are currently testing the Nubigon software, with a particular interest in the transformation from point cloud to orthophoto.
We are encountering several issues when importing the orthophoto into AutoCAD:
The orthophoto does not appear in the exact correct location (there is often a discrepancy of up to 5 cm, which is not accurate enough for our work — we require 1 cm or less).
The deviations between the orthophoto and the control points are not consistent in direction or distance.
The deviations are not consistent when the orthophoto is re-exported from Nubigon.
In principle, the exact same orthophoto is exported, yet each version has slightly different deviations.
The control points do match correctly within the Nubigon software (tested using a .dxf line).
Therefore, the incorrect positioning seems to occur during export.
On one occasion, the orthophoto was positioned correctly — this was when only a small portion of the point cloud was exported.
You can download a .DWG file via the following link, which contains various imported orthophotos and the visible control points.
I expect there is a solution to this issue!
Kind regards,Levi
0 Votes
Bert Azizoglu posted 29 days ago Admin
Hi Levi,
Thanks for your detailed message!
Just to clarify upfront — all orthophotos exported from NUBIGON are to scale, including when using the trial version. There are no limitations or export restrictions that would affect scaling or resolution.
If you’re seeing discrepancies after import, we recommend reviewing the steps outlined here to ensure accurate scaling and alignment in AutoCAD: How to import orthophotos into AutoCAD
Let us know how it goes! If you’re still running into issues after going through those steps, feel free to share more details — we’re happy to help you troubleshoot further!
Best, Team NUBIGON
0 Votes
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