What is the difference between Registration and Alignment?

The Registration and Alignment commands are both located under the Alignment tab inside the application.

Registration is the process of finding common areas of curvature and orienting the overlapping portions of the scans together. Typically 10% of overlap is required to successfully register scans together.

Alignment moves one object into alignment with another object so that they both share the same coordinate system. Alignment orients two objects by pairing corresponding data. The data may be curvature of the parts, Features (for example, cylinders, circles, planes, etc.), or XYZ coordinates. Typically 90% of common data is required to successfully align objects together.

Types of Registration:

• Manual Registration makes adjustments to the spacial position of scans based on user-defined pairs of corresponding points from each object.

  

  
  

  Related article: What are some tips for using Manual Registration?

  
  
• Global Registration makes fine-tuned automatic adjustments to the spacial position of two scans on the basis of all points.

  

  
  

  Related article: I used Manual Registration to get a rough alignment of my scans. How do I fine-tune this registration?

  
  
• Target Registration registers two or more point or polygon objects based on feature targets.

  

  
  

  Related articles:

  Is there any way to speed up the command Detect Sphere Targets?

  How do I remove targets from my object?

  
  

Types of Alignment:

• Feature-Based Alignment aligns one object with another with respect to the datums/features that exist on both objects.

  

  
  
• Best Fit Alignment changes the coordinates of one object to match the other using a best-fit algorithm.

  

  
  

  Related articles:

  How do I perform selection-based Best Fit Alignment?

  How do I force Best-Fit Alignment to ignore parts of a model?

  What are some tips for a faster Best Fit Alignment time of my TEST and REF object with a larger model?

  How does Best Fit Alignment determine how the parts are aligned?

  
  
• RPS Alignment is the alignment of objects using reference points. The points can be constrained to the X, Y, and/or Z axis. This method of alignment is useful when tolerances are more critical in one direction than another.

  

  
  

  Related articles:

  What is the difference between RPS Alignment and Datum/Feature Alignment?

  Why am I having trouble getting Best Fit Alignment to work on a my cylindrical object?

  
  
• 3-2-1 Alignment establishes an X, Y, and Z plane on both the test and reference objects and reorients the test object such that its three planes match those of the reference object.

  

  
  
• Manual Alignment allows reorientation of a test object by manual control of translation, rotation, and rotation center.

  

  
  
• Coordinate System Alignment reorients the Test object in space such that the axes of one of its Coordinate Systems coincide perfectly with the axes of a Coordinate System of the Reference object.

  

  
  
• To World Alignment aligns datums or features of a selected object to planes, axes, or the origin of the World object, or to datums that may have been copied to the World object.

  

  
  
• Last Alignment saves current alignment and allows for opening previous aligment for an object.