What is alignment?
Every Matterport Space is a set of scans. Each scan is a set of 2D and 3D data from one physical position. 3D data from all the scans are combined to create a complete 3D Space.
The first scan is a single point in space. Every scan after that is aligned to a previous scan. A properly aligned scan means it is in the same position in software as in real life.
Generally, the Matterport Capture app aligns by overlapping the 2D and 3D data and searching for areas of high similarity. No GPS data is used for alignment.
If there is no overlapping 3D data, this is an alignment error. The most common reasons for no alignment are:
- Scan distance too far apart
- No line of sight to a previous scan
- Doors opened in one scan, but closed in another
If the scan reports aligned, but did so incorrectly, this is a misalignment. The most common reasons for a misalignment are:
- Mirrors not being marked. The camera doesn't "see" it as a wall, but instead another room.
- Repetitive geometry such as a long hallway or empty warehouse.
- Starting a new floor in Capture far away from the last scan made on the previous floor.
To avoid both problems the general advice is to:
- Mark windows and mirrors as soon as you scan them
- Leave doors either opened or closed.
- Reduce the distance between scans
- Avoid direct sunlight and scanning outdoors
- Keep line of sight from a previous scan.
- Start your new floor right next to where you left off on the previous floor.
An alignment error is when the Matterport Capture app cannot align the current scan to your previous scans. In this case, Matterport Capture will immediately tell you something is wrong.
To recover from an alignment error, reduce the distance from a previously completed scan by half and try again.
If this doesn’t work, delete the previously completed scan and scan over that spot again. Repeat this process of deleting and rescanning until you have recovered alignment.
A misalignment is when the Matterport Capture app thinks it aligned the scan, but it actually placed the scan in the wrong spot. For this reason, there is unfortunately no error message available.
For example, scan 7 was placed between scan 5 and scan 6 in the app. However, in real life scan 7 was where the orange circle is. Scan 7 was a misalignment.
Misalignments can cause navigation problems after the model is processed. Misalignments can also stack on each other. Too many misalignments can make the model unusable.
Misalignments can be easy to miss if you have been scanning for several hours.
To recover from a misalignment, first, delete the misaligned scan. Then half the distance to the previous scan and try again. If this was successful, continue at the normal distance.
If this doesn't work, delete the two previous scans and scan again over the last scan position. So if scan 10 results in a misalignment, then delete scans 10 and 9 and scan again over scan position 8.
Continue at a slower pace (half the normal distance) or lower the tripod until you regain alignment. Remember to hide extra scans in Workshop later. Learn more.
Correctly Aligned Space
|Misaligned Space||Correctly Aligned Space|