Inter-Quake Model (IQM) Format

The Inter-Quake Model (IQM) format is a binary skeletal-animation format designed for extensibility, efficiency, and ease of loading. It is intended to serve as a replacement for the aging MD5 and SMD skeletal-animation formats used in Quake-derived and Quake-like 3D engines. It has a companion export-only format, Inter-Quake Export (IQE), which is an extremely easy to export ASCII format that compiles to IQM, while supporting all IQM features, and is inspired by the OBJ format.

IQM Features:

• little-endian binary format for fast loading
• supports variable vertex attribute formats including position, texture coordinates, normal, tangent, blend weights, color, and custom attributes
• space-efficient quaternion animation encoding
• supports non-uniform joint scaling
• allows combined or separate mesh and animation files
• triangle adjacency data
• per-frame bounding boxes

IQE Features:

• ASCII format with only minimal structure for ease of exporting
• compiles to optimized IQM format
• angle-based smoothing, edge-flag smoothing, and smoothing groups

The IQM development kit can be downloaded here (iqm-2021-06-13.tar.gz, 2839KB). It includes:

• format descriptions for IQM (version 2) and IQE
• IQM compiler for MD5, SMD, FBX, OBJ, and IQE models
• Blender exporter (versions 2.49, 2.56-2.59, 2.60-2.74, 2.80, and 2.93) for both IQM and IQE formats
• sample code/demos for loading and rendering IQM models

The last release of the IQM development kit supporting version 1 of the format can be downloaded here (iqm-2011-05-24.tar.gz, 2270KB). However, it is recommended that all users move to newer version 2 development kits to avoid quality issues with the animation encoding resolved in version 2.

The latest IQM development kit source code can also be retrieved on github.

Games/3D engines that support IQM:

• Cube 2: Sauerbraten
• DarkPlaces
• BananaBread
• OctaForge
• Red Eclipse
• Alien Arena
• Xonotic
• ioquake3
• Warsow
• Unvanquished
• RemakeQuake
• QuakeForge
• Lobster
• FTEQW

Other tools for working with IQM:

• IQM importer and IQM-to-IQE converter by Tor Andersson
• Noesis, an anything-to-anything converter, with support for IQM
• IQE export plugin for Noesis by Vic
• IQE/IQM viewer by Robert Reinhard
• IQE export for Maverick Model 3D by Zack Middleton

News

• 06/13/21 - added Blender 2.93 exporter
• 11/04/14 - fixed handling of multiple root bones in FBX importer
• 07/22/14 - added support for overriding bone order in Blender 2.64+ exporters
• 03/15/14 - fixed static linking against libwinpthread with MinGW-w64
• 03/10/14 - fixed FBX texcoord/color parsing and updated documentation
• 10/02/13 - fixed handling of bone names in de-rigify
• 09/01/13 - fixed bug in IQM compiler channel encoding
• 08/20/13 - fixed some exporter typos
• 08/17/13 - fixed some quantization and rounding issues in the IQM compiler
• 07/28/13 - made Blender exporters use the default armature affecting a selected mesh if no armature is selected
• 07/20/13 - fixed triangle adjacency to use position and span all meshes
• 06/12/13 - added support for loading OBJ format in IQM compiler
• 05/24/13 - added support for mesh combining and some preliminary support for loading FBX 7.x formats in IQM compiler
• 02/02/13 - fixed some compilation errors
• 12/23/12 - fixed some bugs in vertex-color-layer-as-alpha handling
• 05/05/12 - updated Blender exporter to 2.63 and made github repository
• 02/17/12 - updated Blender exporter to 2.62
• 01/04/12 - added support for exporting a vertex color layer as alpha in the Blender 2.59 exporter
• 01/03/12 - fixed bug in IQM exporter with vertex colors
• 12/18/11 - fixed bogus IQE base frame in Blender exporter
• 10/16/11 - updated Blender 2.5 exporter to 2.59 and added support for exporting vertex colors
• 10/3/11 - added support for setting animation properties on command-line to IQM compiler
• 8/16/11 - fixed bug in exporter and IQM compiler/upgrader where tangent vectors had wrong sign
• 7/29/11 - fixed exporter and IQM tools to align structs and vertex data to component boundaries
• 7/11/11 - added toggle for exporting non-skeletal models
• 7/9/11 - added support for half type and vertexarray command to the IQE compiler and fixed bug in GPU skeletal animation demo
• 6/23/11 - updated Blender 2.5 exporter to 2.58
• 6/10/11 - added a demo of GPU-accelerated skeletal animation
• 6/5/11 - fixed Blender exporting of different materials within a single mesh and added options for different material name formats
• 5/31/11 - made new revision of the format (version 2) to fix problems with quaternion W coordinate precision
• 5/24/11 - fixed bug in Blender 2.5 exporter causing faulty bone parents
• 4/14/11 - updated Blender 2.5 exporter to 2.57
• 1/28/11 - fixed bug selecting IQE files to export in Blender 2.56
• 1/4/11 - updated Blender 2.5 exporter to 2.56
• 9/11/10 - updated Blender 2.5 exporter to 2.53
• 4/20/10 - finalized version 1 of IQM format

Contact

If you have questions about the format or have any relevant links you would like added to this site, please contact: