To create guidelines for cataloging digital files for 3D models, we had to begin, as all catalogers do, with the essential question “What are we cataloging?” Should we catalog each set of files published together online, or each individual file? We found it was much easier and more thorough to catalog each file individually, to address its specific characteristics for usability and preservation. Should we consider the 3D scan files as reproductions, or as adaptations? We carefully considered section 3.2 under Special Cataloging Guidelines in OCLC’s Bibliographic Formats and Standards (2012), concerning “Reproductions and Original Microform Publications.” We started thinking that the scans should be considered as reproductions, but we quickly came to realize that the guidelines for cataloging reproductions were insufficient to capture the specific data that was important regarding this kind of electronic resource; the 533 field about Reproductions would be the only substantial place to include information about the 3D Model as opposed to the original artwork. We realized that it was more appropriate to consider each digital 3D scan file as an adaptation, as it “substantially changes the nature and content of that work” (under RDA 6.27.1.5 Adaptations and Revisions, in the RDA Toolkit, 2010) and it is changing “from one medium of the graphic arts to another” (under AACR2 21.16A, also in the RDA Toolkit, 2010). Not only did this decision greatly help with the level of detail regarding the scan that we could include, but it also made it more clear how to approach the Title Statement and Main and Added Entries for the file.
Another aspect that we considered for inclusion in the MARC records but ultimately rejected was the desire to encode technical metadata about the number of vertices and faces in the 3D polygonal models. These metrics can be helpful to certain types of users who want to quickly evaluate the complexity and detail of a 3D polygonal model. The relative difficulty of acquiring this level of technical metadata persuaded us to exclude this information.
-Arden Kirkland and Michael Mansfield
The table below indicates the entries for MARC fields that are specific to cataloging a digital file of a 3D model. Entries that conform to typical entries for all types of objects are not discussed here.
| MARC FIELD TAG | MARC FIELD | Guidelines – MARC |
| Leader/06 | Type of record | m for a computer file |
| 007/00 | Physical description fixed field – Category of material | $a = c for electronic resource |
| 007/01 | Physical description fixed field – Specific material designation | $b = r for a remote resource (accessed online) |
| 007 | Physical description fixed field – Color | $d = n for not applicable, since STL files have no color – see MARC guidelines for other choices that may apply to other file types |
| 007 | Physical description fixed field – Dimensions | $e = n for not applicable, since it’s a remote resource |
| 007 | Physical description fixed field – File Formats | $h = a for one file format, m for multiple, u for unknown |
| 007 | Physical description fixed field – Antecedent/Source | $j = a for file reproduced from original, c for file reproduced from electronic resource |
| 008/15-17 | Fixed length data elements – place of publication, production, or execution | the code from the MARC Code List for Countries for where the scan was captured |
| 008/23 | Form of Item | o for online |
| 008/26 | Type of computer file | c for representational, i for interactive multimedia, m for combination; these scan files are both representational and interactive as the used can turn them in any direction |
| 008/35-37 | Fixed length data elements – Language | zxx for no linguistic content, eng for English – see MARC Code List for Languages for others; STL files have no linguistic content, but other 3D model file types might |
| 110 | Main entry – Corporate name | From AACR2 21.16A, “Enter an adaptation from one medium of the graphic arts to another under the heading for the person responsible for the adaptation. If the name of the adapter is not known, enter under title.” |
| 245 | Title statement | $a original title $h general material designation as [electronic resource], $f date of scan / $c statement of responsibility with both responsibility for the scan and the original artist; 1 for indicator 1 indicates an added entry, in this case both 110 and 700, following AACR2 21.16A Adaptations of Art Works and RDA 6.27.1.5 Adaptations and Revisions |
| 246 | Varying Form of Title | $ the variant form of the title as shared in a repository, $g a phrase describing the other title; 0 for indicator 1 is for a note with no added entry, 3 for indicator 2 specifies the type of title as “Other title” |
| 246 | Varying Form of Title | AACR2 9.7B4: “Optionally, transcribe a file name or data set name if it differs from the title proper.” $i phrase introducing the filename: $a filename; 0 for indicator 1 is for a note with no added entry, blank for indicator 2 shows that the type of title is not specified (as it is specified instead with subfield $i) |
| 256 | Computer File Characteristics | following the format Electronic Data (<number of files> <file type>, <file size>). Similar to 347, but in a display format. |
| 264 | Production, publication, distribution, manufacture, and copyright notice | The publisher will be the entity making the scan available. |
| 336 | Content type | Because the three-dimensional image can be rotated, the content type is three dimensional moving image. |
| 337 | Media type | for all 3D model files, this will be “$a computer $b c $2 rdamedia” |
| 338 | Carrier type | for all 3D model files, this will be “$a online resource $b cr $2 rdacarrier” |
| 347 | Digital File Characteristics | Similar to 256, but in a structured format |
| 518 | Date/Time and Place of an Event Note | A statement to describe the date/time and place of the capture of the scan. |
| 500 | General Note | Any other important information about the scan can be placed here. |
| 508 | Creation / Production Credits Note | Information about people involved in the production of the scan should be listed here if the overall responsibility is considered to be corporate, or if additional people worked with the main person responsible. |
| 520 | Summary, etc. | A statement to summarize information about this resource, making clear the nature of the digital resource. |
| 538 | System Details Note | A statement regarding system / software / hardware requirements for use of the resource, using $u for links to required resources. |
| 540 | Terms Governing Use and Reproduction | $a = rights statement, $u = link to more information |
| 655 | Index Term – Genre/Form | for digital files for 3D scans, this can always be “Three-dimensional imaging” from the Library of Congress Subject Headings; use indicators #0 to show that it is a basic heading (not faceted), and that the term comes from the LCSH |
| 700 | Added entry – Personal name | From AACR2 21.16A, “Make a name-title added entry for the original work.” This should include: $i an indication that this is a 3D scan of an original work. $a original artist name $d dates associated with the original artist $e the relationship designator for that person, usually “artist” $t the title of the original work $f the date(s) of the original work |
| 856 | Electronic Location and Access | $u = url to the exact file for download; indicator 4 in the 1st position shows that HTTP is the access method; a 0 in the 2nd indicator position shows that the provided link is to the exact resource described in this record |
| 856 | Electronic location and access | A link to any related resources, such as alternate file types on Thingiverse. $u = url, $z = public note, $3 = Materials specified; indicator 4 in the 1st position shows that HTTP is the access method; a blank in the 2nd indicator position shows that no information is provided about the relationship between this resource and the item being cataloged, as the other indicator types are not appropriate for alternate file types |