Module omf::omf1

Expand description

Convert existing OMF v1 files to OMF v2.

There are a few parts of OMF1 that don’t map directly to OMF2.

The date_created and date_modified fields are moved into the metadata.
The subtype field on point-sets and line-sets is moved into the metadata. On other elements, where it only had one valid value, it is discarded.
Line-sets and surfaces with invalid vertex indices will cause conversion to fail.
Line-sets and surfaces with more than 4,294,967,295 vertices will cause conversion to fail.

Scalar data becomes a number attribute, preserving the float/int type of the array.
In number data, NaN becomes null.
In 2D or 3D vector data, if any component is NaN the vector becomes null.
In string data, empty strings become nulls. OMF2 supports both null and empty string so we can only guess which was intended.
In date-time data, empty strings become null.
Date-times outside the range of approximately ±262,000 years CE will cause conversion to fail.

The exact layout of mapped data from OMF v1 can’t be stored in OMF v2. It is transformed to a category attribute by following these rules:

Indices equal to minus one become null.
Indices outside the range 0 to 4,294,967,295 will cause conversion to fail.
The most unique, least empty, and shortest string legend becomes the category names, padded with empty strings if necessary.
The most unique and least empty color legend becomes the category colors, padded with gray if necessary.
Other legends become extra attributes, padded with nulls if necessary.

Structs§