GAMMA AR Application

Learn essential tips for correcting model positioning, handling technical issues and learn best practices in GAMMA AR.

Everything appears off even though I positioned the model accurately.

This might be an indication of:
1. Wrong anchoring of the model (e.g. a similar-looking element that in fact is placed somewhere else)
2. Height anchoring might be wrong and make it seem to be off horizontally. Suggestion: Verify vertical alignment with elements like beams slabs, ceilings, bolts or openings that might be in your vicinity.
3. Deviation between the model and reality (reasons might range from not up-to-date model to wrong execution)
4. Drift
5. A discrepancy in the model coordination points (in case several non-federated models are superimposed)
Where do the categories that are displayed come from?

The categories in the GAMMA App are based on ISO certified IFC categories. Other categories are mapped to those accordingly.
Why don’t I see the same colors I have in my model?

Make sure that within project settings >> materials, the option “original” is chosen. If standard is chosen, GAMMA AR overrides the categories with default color coding by category.
The project list takes very long to load

If the user is invited to many projects or the internet connection of the device is weak, the project list might take a while to synchronize and load.

Tipp: turning the flight mode on the device (or simply turning off the internet connection) will interrupt the synchronization attempt and the project list will load quickly only with projects that have models downloaded to the device
How accurate is the positioning in the app?

The accuracy of the positioning depends on the precision with which the model is anchored in the first place and any subsequent adjustments by the user her-/himself. And while LiDAR enhanced devices might improve the speed of positioning by snapping the model to corresponding edges on site of existing elements, construction tolerances and differences between design and execution will very likely prevent perfect overlay.
How do I recognize drift?

If several objects are aligned, but some aren’t, and this continues to be the case when moving, then there might be a discrepancy between the built reality and the design. If all elements seem to be misplaced in the same direction, there is a big likelihood of drift.
Why is there drift?

A drift of the model can occur when the device used to visualize the model cannot establish its correct spatial position. The reasons for this might be related to many factors:
1. Device-related:
  1. the device might not have LiDAR technology and cannot perceive the depth of the environment
  2. the device (especially true for less performant and older versions) might be operating at the limit of its capacity and storage
2. Environment-related:
  1. bad lighting on the site,
  2. many moving objects in front of the camera,
  3. large empty spaces without many elements (even LiDAR-enabled devices cannot reach elements farther away than 7m)
3. Usage-related:
  1. the area of the camera could have been covered (even only shortly),
  2. the user might have kept the device directed towards one surface for a longer period while moving (e.g. just directed at the floor without the device being able to recognize other surfaces while walking)
  3. the user might have performed a number of very large and quick movements
How do I correct drift?
1. Repositioning the model entirely (go to “reposition” within the hamburger menu on the top right)
2. Use the automatic alignment suggestion (on the right panel)
3. Use QR Codes
4. Use the offset tool moving around the model in the horizontal plane, changing manually the height and adjusting the rotation of the model.
  
  Good to know: to make sure that the you realign the model correctly, it is important to ensure that there is no difference in height (which might otherwise change the perspective). Wrong height of the model positioning can be seen if the elements appear wrongly scaled and if adjusting the position of the model on one side does not correct the view from a different point of view. What to do: choose a right corner, stand in the continuation of one of the planes and adjust the model’s position only in the perpendicular direction. Then stand in the continuation of the other plane and again adjust strictly the perpendicular direction of the model (even if the corner you are trying to adjust will not be properly aligned). Then stand diagonally across the corner and shift the model only vertically until it aligns with the corner.
What are the best practices to avoid drift?

It should be noted that since augmented reality is an indicative tool and not a surveying device, and as long as the construction process accepts tolerances and the design generic placeholder elements, perfect overlay of all elements is very unlikely. In general, better hardware (e.g. LiDAR enabled tablets) provides a better experience.
Why do I need to download the models again in the app?

Every time the user logs out, the app erases stored data for security reasons. We recommend not logging out on your own device. Also, the model might have been updated to a new version or the previous download was not completed.
Can I log in without an internet connection?

No, in case you explicitly logged out of GAMMA AR, it will not be possible to access the platform without confirming your credentials through the internet. Please note that it will also be impossible to download the model (since it is erased from the internal memory every time the user logs out). Once logged in, the app can be used without any internet connection.
Do I need to log in every time I re-open the app?

No, once you are logged in on a device, you can exit the app and restart the device at your leisure without being logged out and having the downloaded models erased, this also works offline.
Does the app recognize differences between reality a model?

No, the app visualizes the model and allows the user to compare intuitively design against the job site/building. Any identified deviation needs to be assessed for logic (drift vs true difference) and the appropriate action needs to be decided by the user (creation of issue to indicate a request for model adjustment/ an information request/change order or nothing if deviation is immaterial or irrelevant)
How should I work with GAMMA AR?

During your rounds: Check reality against the model for existence of objects and correct execution. If deviations are found, reposition/realign close to the location of the issue to ensure absence of drift and more precise assessment of the potential issue at hand.
The model is out of scale, how do I scale it up again?

Unless using the miniature mode, the model appears always in original scale. Any deviations in size of elements may suggest a wrong height placement of the model. Another reason might be wrong export from CAD systems resulting in unit errors.
I don’t see anything when loading GAMMA AR or the app tells me that there are no elements in the range to position on.

Check the uploaded model in a viewer. Chances are, the models might not be coordinated (and some elements might not have the same coordinates as the positioning model in which case the surveyor point setups should be checked across all models) or the export might not include any elements (if e.g. a shared model is uploaded without the proper export settings). In case no elements appear in the floorplan, it might be the case that the chosen model does not include any standard positioning elements (on this floor). Activate other elements for positioning in the project settings or check the model.
When trying to place the pin, the floor grid is moving or drifting away

We suggest to move the device around so that it can capture the environment correctly (large circular and shifting movement as if you were stirring a huge pot with your device while tilting it towards the ground and back up again), if this problem persists, force-close the app and reopen it.
My device gets hot and the battery empties quickly.

We recommend to turn on the airplane mode while using GAMMA AR to improve the ergonomics of the device. AR requires a lot of processing power and energy. If you need more usage time, powerbanks can be useful.
The visualization is lagging

When walking, GAMMA AR will continuously load the environment dynamically. It is recommended to reduce the loading range to have a smoother experience. In case of lags while standing, the loading range should be reduced as well as some of the superimposed models could be hidden to decrease the number of objects that are rendered. It should be noted that more recent and better devices improve the performance.
Why do I see “update” next to my model

Indicator of a failed download process. It is recommended to use a stable internet connection when downloading the models. Also, in case of many models in the project, it is recommended to download the models one by one and not in bulk.
My project is greyed out

Your license is expired. Please reach out to your point of contact at GAMMA AR or to info@gamma-ar.com to request the activation of a new license.
The app crashes when opening model

Reduce the loading range in the project settings and decrease the categories available for positioning. It is recommended to use smaller models to anchor the model to accommodate the performance of the device (and other models can be appended when in AR mode) or to switch to QR-code based positioning.
App crashes in miniature mode

In miniature mode, all objects are loaded, which can cause a memory overload, depending on the device. Choose more performant hardware to visualize the model or reduce the number of objects within the model.
It appears as if my model was floating

In case the model objects in your close vicinity appears to be visualized correctly (i.e. model floor seems to be on the real floor) but distant, or objects obstructed by real objects seam to follow you or “float”, you might be experiencing what is called the parallax effect. This visual effect appears for example when visually comparing a real object with a digital one of a different size (e.g. visualizing a floor in the model that is 30m long in a 3m wide room). When you move in the direction of the “floating end”, the model within the surrounding of the user will remain correctly positioned at the floor. If this effect is disturbing, it is recommended to reduce the vision range (e.g. to 10m) so that all objects beyond 10m distance are hidden.
I don’t see the model I uploaded on the portal.

Please verify in the portal of which region the model was uploaded (Global vs EU) and in which region you are logged in within the app.
Why are all my models gone that I downloaded?

The models are not visible as long as the download was not completed. If the models were fully downloaded on the device, there are two possibilities to erase them: within the project’s menu and by logging off from the account (in both cases warning messages appear).
Do I need internet to work with my models?

No. Once a model is downloaded from the cloud to the device, no internet connection is needed. The app runs then in offline mode and any issues collected or progress tracked will be ready for synchronization with the web platform and other integrated platforms once the device is connected with the internet again and the app is opened.

Best practice is to check for potential model updates before any site visit and synchronizing notes to the cloud immediately upon returning from the site.
Can I measure distances with GAMMA AR?

Yes, when in AR mode, there is a possibility to access the measuring tool (within the menu list on the top right). Measures can be taken between two points either in reality (yellow) or model (green) or a combination of the two by turning on/off the “flower mode” or the “3D mode”. It should be noted that measuring in AR remains indicative and should not replace conventional measuring methods.