BIM Inspect Align

This command allows to align the scan with the global BIM model.

This step is optional if data are already registered.

images/download/attachments/113547156/qa2021_n2632.png

Pre-align

A popup is displayed when both objects are too far from each other: choose which object to move.

  1. Select the object to move. It becomes blue and you will be able to handle it in Top and Front ortho cameras.

    Controls guideline

    • All movements are performed in 2D screen direction.

    • Translate horizontally and vertically with arrows.

    • Freely translate with the central button.

    • Rotate around the central button with the circle.

  2. Optionally, if the manipulator is not centered enough, you can change its position thanks to Position button.

  3. Attraction: t his threshold defines how far a point is considered as overlapping the one on the other object when performing a best fit.

  4. Check Preserve Z axis orientation to forbid rotation around X and Y axes.

  5. Click Best Fit button to improve automatically the registration.

    1. Additional best fit parameters can be customized (BIM Inspect Specific Settings).

    2. The mean deviation will be displayed and colored according to the specified tolerance. However, out of tolerance best fit are allowed.

    3. Click Undo to cancel the last best fit.

  6. Then click Next to validate and continue (BIM Inspect Clean ).

Modifying the registration later will cancel previous workflow results, if any.

Best fit tips

In order to provide an optimal result, the best fit relies on several factors:

  • The initial positions of the model and the scan: both elements must be positioned as close to each other as possible and share a significant amount of overlapping areas.
    A good practice is to spend some time to make an accurate manual alignment before launching the best fit.

  • The presence of scanning direction on the scan points: it allows attraction between surfaces with the same orientation. Useful for walls for examples.
    If scanning direction are not available on the points, a warning message will be displayed at the BIM Inspect Scan step.

  • The attraction value: setting a large value may lead in attraction between inconsistent features. On the counterpart, with a too low value, interesting points may be skipped.

A more complete documentation regarding the best fit calculation can be found in Best Fit Registration.