Point Cab

Transformation calculatorチュートリアル

■ Merge two geo-references projects into one
■ Merge two overlapping projects into one
■ Represent differences between prior and current data collection in a project
■ Generate and geo-reference a point cloud from CAMERA DATA FROM A DRONE FLIGHT BY PHOTOGRAMMETRY

  • In just one step, you can transfer a whole project or a point cloud generated by any laser scanner or from flights with drones into a desired coordinate system, e. g. a total station system or another point cloud system.

    Moreover, you can calculate an additional difference in scale. The scale can be respected during a re-import of the scan project.

  • Merge projects or point clouds: By means of geo-referencing, at least four known reference points, e. g. from GPS or total station measurements, are assigned to 3D points defined in the point cloud.

    You can also merge projects without geo-referencing in PointCab if their point clouds overlap. In that case, you have to select the same reference points in each project.

  • Correlation search: For transformation, correct correlations between reference points and defined 3D points have to be created. If manually realized, this procedure might take up a lot of time. Due to the automatic correlation search, this step is done at the touch of a button. Superfluous points from the reference point list and the 3D points list are removed in this step. The attribution of points can also be done having regard to the different scales as they might appear in point clouds from drones.

Tutorial units

  • Transformation calculator

    1. Import your scan project.

    2. Define the reference points using the 3D Points tool (here: drains), we have 5 points here.

    3. Start the “Tranformation Calculator” and add the reference points from a coordinate file.

    4. Search the correspondance automatically by pressing “Search constellation” and check the residuals.

    5. Select “Align” and click on OK in the dialog.

  • Register two different projects