What is MIME type "application/vnd.maxar.archive.3tz+zip"?

A MIME type is a string that tells browsers and other tools how to handle a particular kind of file.

The MIME type application/vnd.maxar.archive.3tz+zip designates a specialized ZIP archive for 3D tiles. It bundles files used to represent geospatial data in 3D formats. Each archive holds different pieces that work together in mapping software.

Files in this archive include metadata in JSON, 3D models in B3DM and I3DM, combined tiles in CMPT, and point cloud data in PNTS.


The archive ensures that all pieces of a 3D scene are kept together and can be easily loaded by compatible applications. This organization helps in managing complex 3D data while keeping file sizes under control. For more on MIME types and their roles, see MIME on Wikipedia.

Associated file extensions

.json, .b3dm, .cmpt, .i3dm, .pnts

Usage Examples

HTTP Header

When serving content with this MIME type, set the Content-Type header:


    Content-Type: application/vnd.maxar.archive.3tz+zip

HTML

In HTML, you can specify the MIME type in various elements:


    <a href="file.dat" type="application/vnd.maxar.archive.3tz+zip">Download file</a>

Server-side (Node.js)

Setting the Content-Type header in Node.js:


    const http = require('http');    
    
    http.createServer((req, res) => {    
      res.setHeader('Content-Type', 'application/vnd.maxar.archive.3tz+zip');    
      res.end('Content here');    
    }).listen(3000);

Associated file extensions

.json, .b3dm, .cmpt, .i3dm, .pnts

FAQs

What is the primary use of application/vnd.maxar.archive.3tz+zip?

This MIME type is used to serve 3D Tiles archives, specifically those packaged by Maxar. It bundles geospatial data, including metadata and 3D models, into a single compressed file to facilitate efficient streaming and rendering in mapping applications like CesiumJS.

How do I configure Apache to serve .3tz files correctly?

To ensure your Apache server sends the correct headers for Maxar 3D archives, add the AddType directive to your .htaccess or configuration file. Use the line: AddType application/vnd.maxar.archive.3tz+zip .3tz.

How do I add this MIME type to Nginx?

For Nginx, you need to update your mime.types file or the types block in your server configuration. Add the entry: application/vnd.maxar.archive.3tz+zip 3tz; to ensure browsers and GIS clients recognize the file format.

Can I open this file type with standard ZIP software?

Yes, the +zip suffix indicates that the file uses standard ZIP compression. You can often rename the file extension to .zip to extract and inspect the internal contents, such as json metadata or b3dm models.

What is the relationship between this archive and files like B3DM or PNTS?

The application/vnd.maxar.archive.3tz+zip file acts as a container. It holds the individual components of a 3D scene, such as Batched 3D Models (b3dm), Point Cloud data (pnts), and Composite Tiles (cmpt), keeping them organized for the viewer.

Why use this specific MIME type instead of generic application/zip?

Using the specific vnd.maxar.archive.3tz+zip type explicitly informs the client application that the ZIP file contains structured 3D geospatial data. This allows specialized software to automatically parse the tile hierarchy rather than treating it as a generic download.

Is this MIME type supported by all web browsers?

Most modern browsers do not natively render 3D tiles without a specialized library (like CesiumJS or Mapbox). However, they will correctly download the file if the server sends the proper MIME type, allowing JavaScript applications to process the data via fetch or XHR.

General FAQ

What is a MIME type?

A MIME (Multipurpose Internet Mail Extensions) type is a standard that indicates the nature and format of a document, file, or assortment of bytes. MIME types are defined and standardized in IETF's RFC 6838.

MIME types are important because they help browsers and servers understand how to process a file. When a browser receives a file from a server, it uses the MIME type to determine how to display or handle the content, whether it's an image to display, a PDF to open in a viewer, or a video to play.

MIME types consist of a type and a subtype, separated by a slash (e.g., text/html, image/jpeg, application/pdf). Some MIME types also include optional parameters.

How do I find the MIME type for a file?

You can check the file extension or use a file identification tool such as file --mime-type on the command line. Many programming languages also provide libraries to detect MIME types.

Why are multiple MIME types listed for one extension?

Different applications and historical conventions may use alternative MIME identifiers for the same kind of file. Showing them all helps ensure compatibility across systems.