CamBar Measure Tool
To help with checking the quality of the camera tracking, an interface for measuring distances is available in the UI.
The measuring tools offer a convenient way of measuring distances from the CamBar perspective.
It is helpful to measure the CamBar in isolation as often when observing issues with tracking, the problem may stem from differing areas and being able to isolate and measure elements independently is vital for troubleshooting
The measuring tools are available from the tracking dashboard and can be accessed via this button
Two different modes are available
Measure Tool - Allows for measuring the distance between two of the tracking features selected by the user
Travel Tool - Provides a distance the CamBar has travelled from a selected point to it's current position, this is useful for comparing a physical move to the corresponding virtual move
When the measure tool is activated, the user is able to select two tracking features in the environment and the inferred distance between the points will be displayed to the user.
When using this method, be aware that:
- Tracking features in the distance will not be accurately detected in terms of position, this is expected.
- The more the camera has moved through an environment, the more refined the pointcloud and ultimately the measurements will be
- Unreliable tracking features such as reflections etc will not provide an accurate measurement and they should be avoided
- Due to the resolution of the witness cameras, and how the feature detector decides on the exact location of a tracking feature, this method is not suited to provide highly accurate measurements
As a result, the measure tool is recommended more as a convenience feature than for accurately checking the CamBar calibration
The travel tool allows the user to pick a "Start" point and then displays the distance the CamBar has moved relative to that starting position.
This allows a user to move the CamBar a known distance in the physical world and compare that to the reported distance in the software.
This method typically gives a better result than the measure tool but does require careful measuring and movement of the CamBar to achieve
When using the tool:
- Try and move the CamBar at least 2-3m to help get a good measurement
- Learning the tracking features prior to setting the start position will produce a better result. To do this, move the CamBar the full distance of your intended measurement area before moving back to the initial position and pressing "Start"
- Pick a point on the CamBar to measure from and ensure when moving and measuring the distance travelled that it is relative to the same point on the CamBar
- The tool will work in either Marker or Natural tracking mode but does rely on good quality tracking to be present, so if attempting the process with a poorly setup marker config or bad natural tracking features then errors are expected
There is an expected error result of approximately 1% with the Scenario system. This means if the Cambar moves 1m physically, a distance of 0.99m or 1.01m would be reported by the software.
If larger discrepancies than this are observed it could indicate an issue with the CamBar calibration or the tracking environment