Aligning by Best Fit

You can reposition a cloud of points with respect to reference elements, using best fit.

Before you begin: Align by Best Fit requires you have access to Digitized Shape Preparation.
See Also
Aligning using the Robot
Activating a Portion of a Cloud of Points
  1. Make a first rough alignment before starting Align by Best Fit.
  2. Select a geometrical set as Define In Work Object to store the output.
  3. From the Control section of the action bar, click Align by Best Fit.
  4. Select the Cloud to Align (this is the cloud to reposition).
  5. Select the References (Either a set of clouds or meshes or surfaces, or a set of points).
  6. Use Multi-selection and Hide/Show as required.
  7. Optional: Activate areas (Activate ) in the cloud to align and the references.

    By default, the alignment is computed on the whole cloud to align and on the whole references. However, in some cases (for example when the cloud to align and the references have the same global shape except on some portions), computing the alignment from the whole cloud to align may lead to unexpected results whereas computing the alignment from the areas that are identical leads to a better result.

    Note: The whole cloud to align is moved in both cases.

  8. Decide to keep the initial cloud or not.

    By default, the Keep Initial check box is selected:

    • The initial cloud to align is kept as such.
    • A copy of this initial cloud to align is made and appears in the tree.
    • This copy is aligned with the references.

    1. Clear this check box if you do not want to create a copy of the initial cloud to align, for example because of its size. The initial cloud to align itself is aligned with the references.

      Note: To avoid inconsistencies, you cannot clear the Keep Initial check box in the following two cases:
      • When the geometry of the cloud to align is shared by other cloud elements, for example when the cloud to align shares points or vertices with another cloud without any parent/child relationship between them. Clearing the Keep Initial check box would move the other cloud together with the Cloud to Align, which you do not want to.
      • When the cloud to align is a feature, for example a Generative Shape Design transformation feature.

  9. Click Apply.
    A progression bar is displayed. Click Cancel to stop the computation at any time. The cloud to align or its copy is moved toward the references.
  10. Click More to display the Statistics.

    • Number of iterations
    • Number of points used in statistic calculation
    • Minimum deviation
    • Maximum deviation
    • Standard deviation.

  • If Keep Initial is selected, a new cloud, in fact the copy of the initial cloud to align, is created, and aligned with the references. The new cloud has the same graphic properties as the initial cloud to align.
  • If Keep Initial is not selected, the cloud to align is aligned with the references and no new cloud is created.
  • In both cases, an Axis Systems is created with an AxisRef.x (system axis computed on the cloud to align) and an AxisTrs.x (axis system created on the output cloud).
  • Those Axis Systems can be used with the Axis to Axis action on other elements to align.
  • Align with previous transformation is available.