One question I often receive from users is:
“My two scan projects look perfect individually, but why does the alignment fail when I try to merge them?”
Today I’d like to share what happens behind the scenes and some practical tips to improve alignment success.
For multi-project automatic alignment, the software needs to find the relationship between scan projects. The process is simple:
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Extract matching markers or geometric features from both projects.
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Find corresponding areas and calculate the best transformation to align them.
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Check the alignment quality based on the remaining differences between matched markers or features, known as the residual.
A smaller residual usually means better alignment quality.
However, automatic alignment can still be challenging when:
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There are fewer than 3 common markers between projects.
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The overlapping area has insufficient, repetitive, or symmetrical features.
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The object has narrow or enclosed structures, and the alignment areas are mainly located on flat or curved surfaces with limited features.
So, let me share 3 practical tips to achieve better Auto Alignment results.
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Increase the overlapping markers or features between projects.
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Distribute markers naturally across different areas and orientations of the object. Avoid placing them in a straight line, regular patterns, or too close to each other.
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Add some feature-rich objects around the scanning area to provide more common features for alignment.
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For challenging cases, consider using manual alignment for additional control.
Of course, different objects can bring different alignment challenges.
What objects have you found difficult to align?
Share your experience below！
