Creating Accurate 3D Models with RTK Videogrammetry
Create accurate 3D models with your smartphone. How? Watch our step-by-step guide for handheld RTK videogrammetry with 3Dsurvey software.
Introduction to Videogrammetry
Welcome to our videogrammetry tutorial! We’ll show you how to capture high-quality footage using an RTK device and mobile phone, turning it into a precise 3D model. Videogrammetry is particularly useful when drone flights are restricted, allowing detailed documentation of complex structures and volume calculations.
Setting Up Your Device for Filming
To start, open the NTRIP client app, connect, and confirm accuracy under 0.02 meters. Then switch to the 3Dsurvey SiteScan app, where accuracy is displayed on the screen. Once ready, start filming slowly, maintaining consistent distance from the target, and avoid jerky movements to ensure clarity. Keep key areas in the center of the frame for optimal results. Remember to disconnect from NTRIP after use to avoid charges.
Extracting Images from Video
After filming, transfer the video to your computer and open 3Dsurvey. Go to Images and select Extract Images from Video. Choose your video file as input, select an output folder, and pick Telemetry Extraction Mode. Ideally, you’ll get around two images per second. Click OK to extract images.
Importing and Adjusting Telemetry Data
The telemetry importer opens automatically. Choose your coordinate system and import data. For precise results, input GPS camera offset measurements (refer to the manual if needed), then close the telemetry window.
Performing Bundle Adjustment
Move to the Bundle Adjustment step, using Global Mode. Open advanced settings, keep default feature detection and pair selection, and set Use Telemetry Data for Orientation to No. Click OK to complete the bundle adjustment, where you’ll see a sparse point cloud with camera locations.
Dense Reconstruction and 3D Mesh Creation
Next, click Reconstruction to generate a dense point cloud. With default settings, click OK to start the process. After completion, a detailed point cloud will appear. To create a 3D mesh, go to Mesh in the toolbar, select Calculate New Full 3D Mesh, and click Calculate.
Conducting Measurements and CAD Drawings
Once the 3D mesh is complete, proceed to the CAD tab for measurements or to draw CAD lines directly on the mesh, providing an accurate model ready for analysis.