Establishing a QR marker network

For best performance, Trimble recommends installing markers on a flat, vertical surface such as a wall or column. Sloping or horizontal placement of markers is supported, however a lot more care is required when installing a sloping or horizontal marker to ensure the marker alignment is accurate.

• The markers should be flat, and securely fastened on all four corners. Any wrinkles or curvature of the marker may adversely impact model alignment.

• The markers can be laminated to provide protection from water / dampness.

• To ensure optimal performance, Trimble recommend placing Markers with as much clear, flat space around them as possible, as opposed to right at the edge or corner of a surface.

Immediately after scanning a Marker to place a model, the model should be very well aligned and accurately located. However as you move around, and the further away from the marker you get, you will see the digital model will drift out of alignment with the real world. This is completely normal, and reflects the present limitations of this type of visualization technology when unaided by GNSS. The extent of this drift will vary depending on the device you are using—the more recent the device model, the less drift you should expect to see.

To manage this drift, it is recommended to establish a network of Markers around your jobsite. These can be placed in critical locations, or more generally around the jobsite depending on your needs. As a general guideline Trimble recommends operating within 5 to 10 meters (5.5 to 11 yards) of a Marker, so Markers placed every 10 - 15 meters (11 - 16.5 yards) should prove sufficient.

Markers are created and managed within Trimble Connect Web, using the Trimble Connect Marker extension. Whoever is responsible for creating and managing the Marker network will need to install the Trimble Connect Marker extension.

1. Load your 3D model in Trimble Connect.

2. From the right end of the ribbon menu, select Settings / Extensions.

3. Activate the QR Marker extension by clicking the toggle switch.

   

Creating Markers

Once the Trimble Connect Marker extension is installed, it will be available within Trimble Connect Web when any 3D model is loaded.

1. Load your 3D model in Trimble Connect.

2. From the left panel, click the Trimble Connect Marker extension icon:

3. Navigate in the 3D view to where you want to create your Marker.

   It can be helpful to use the Clip Plane feature of Trimble Connect to expose interior sections of the model.

4. Click Create New Marker to create a Marker, then click the desired location in the model. The location you click will correspond to the bottom left corner of the QR code portion of the Marker.

   The created Marker appears in the 3D view, and the Marker management pane is opened automatically.

   

5. Here you can make adjustments to the X and Y positions or Elevation of the Marker in terms of your model coordinate system.

   Use this approach to reference known survey control points on your jobsite.

   You can also use the Set Reference Point feature to reference other model components to assist with accurate positioning of the Marker. When you click Set Reference Point, you are prompted to select a point within the 3D view; the X, Y, and Z Reference Offset values are then displayed. Manually editing these values will adjust the location of the Marker while keeping the reference point fixed. You can click Redo Reference Point to select an alternative reference point if required.

   

   Use this approach to accurately place Markers with a tape measure at standard heights / offsets to allow for easy setting out in the field.

6. Click Save to confirm the creation of your Marker, and return to the Marker list.

   

Clicking next to the Marker enables you to Edit, Delete, or Download the Marker as a PDF.

When you have created all the Markers you require in Trimble Connect, you must install the Markers in the field.

1. Download and print the Marker PDFs. The Download all button is a useful shortcut if you are managing a large number of Markers.

   IMPORTANT - Ensure when you print the markers that there is no page scaling applied. The Markers must be printed at 100% size.

   

   The Marker printout contains Setout Point coordinates which correspond to the location of the lower left corner of the QR code. These coordinates are expressed in terms of the parent model coordinate system. The Marker printout also features Setout Guide Lines to assist with aligning the Marker on site. The Reference Point Offsets and Marker Creation data are also displayed.

2. Install the Marker on-site either with a tape measure, or by keying in the Setout Point coordinate to a Robotic Total Station or similar setout tool. Make sure the Marker is securely fastened on all four corners and sits flat on the surface.

   There is also an option to download a .CSV file containing all of the Marker Setout Point coordinates. This .CSV file is formatted to be imported directly into Trimble Field Link, which is used in conjunction with Trimble Robotic Total Stations to accurately position setout points with a visible laser.

Once your Markers are installed on-site, any SiteVision user with access to the project will be able to use the Markers to place any model within the project. This is important to understand as Markers are most frequently installed using structural models. As long as your other project models (such as Mechanical, Electrical, etc.) all share the same coordinate system, they will be able to be positioned using the same set of project Markers.

Markers can also be used to load the model within the SiteVision app. This is especially useful where a single federated model is being used, and enables field users to easily load the correct model without having to locate this in Trimble Connect.

For further information on loading and placing your models using Markers within the app, see Placing a model: marker placement.