Starting points are a built-in functionally usable directly
in 3DSizeMe. The only pre-requisite is using the “Automatic” scan mode in the
application.
To ensure so, navigate to the settings and under the Scan
section, set the Scan box placement strategy to “Automatic”

If the setting is properly activated, a guide will appear
with reference markers to help scan, as illustrated below

Different types of scans will have different types of
references to guide through the placement of the scanner to initiate a scan. If
needed, please refer to the corresponding article available in the knowledge
base.