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Mark Callow


Extensive high-level software engineering background creating and developing cutting-edge software products designed to keep companies at the forefront. Solid experience with leading edge high-tech organizations. Respected for broad technical skills, creation of easily understood code and ability to articulate complex design issues.

  • 3D Graphics and Animation

  • Collaborative Tools

  • Interaction Design

  • Digital Media

  • Window Systems

  • OpenGL ES, OpenGL and WebGL

  • Video Conferencing

  • Web Page Design

  • Multi-threaded Programming

  • Operating Systems


  • Co-architected MascotCapsule V4, an M3G
    [Mobile 3D Graphics API for Java.]
    1.0 compliant 3d graphics engine for mobile devices, managed its worldwide development team and played a key role in licensing it to Sony Ericsson for inclusion in all phone models of the era.

  • Architected and implemented ShadowChaser3D, an innovative golf swing training application that overlays a 3d animation of a perfect golf-swing over still or video images of the student golfer.

  • Created Animailer, a web site and underlying technology that enables people to send animated 3d characters and live data applets embedded in e-mail messages.

  • Conceived, and implemented in CosmoPlayer 2.0, a method of streaming animation data into VRML scenes resulting in Cosmo’s Bliss.com VRML multicast showpiece at Siggraph '97.

  • Designed the interaction metaphors and user interface of InPerson, a collaboration tool. This innovative, easy-to-use application provides audio & video conferencing, a shared whiteboard and a unique shared bookshelf. This application generated approximately $3M in revenue.

  • Invented enabling technology for collaborative tools including a shared presentation tool and shared movie player. The latter, with InPerson, became the cornerstone of Sprint’s Drums service.

  • Created CDman and DATman, the world’s first applications to read and play digital audio data from CD and DAT drives and to record audio data to a DAT drive.

  • Replaced SGI IRIX window system with completely different one based on NeWS without breaking existing applications.

Technical Expertise

  • Languages: c, c++, GLSL, JavaScript, Java, Bash, Python

  • Web: HTML5, CSS, WebGL, Emscripten

  • OS: Unix, GNU/Linux, Windows, OS X, iOS, Android

  • Tools: Visual Studio, Xcode, Eclipse, Make, GYP, Cmake, Jenkins CI

  • APIs & Toolkits: OpenGL {,ES}, SDL 2, Vulkan, Win32, CGI

  • and much more…

Professional Experience

HI CORPORATION, Tokyo, Japan 2002 - 2015

Chief Architect

Co-architected MascotCapsule V4. Architected related tools: a 3d Studio Max exporter, a text-based file format and V4 Examiner, a tool for exploring M3G data. Managed 8 person worldwide team developing and releasing this engine and tools. Improved source configuration management practices. Created application SDK.

Contributed to design of subsequent 3D engines.

Mentored junior staff.

Was the ultimate resource for all OpenGL {,ES} issues including resolving the most difficult to find usage bugs.

Representative to JCP making extensive contributions to M3G 1 & 2.

Representative to the Khronos Group contributing extensively to OpenGL ES, OpenGL and EGL.

Representative to MPEG, co-authoring part 21 of MPEG 4.

Researched ways of porting HI’s eruption 3d engine to the web platform including Google Web Toolkit, Mandreel and Emscripten.

Using GYP and SDL2, created a supremely portable application framework for HI’s latest 3d engine. Converted existing applications and created new simple examples. Set up continuous integration building for Windows, OS X, iOS, Android and the Web Platform.

EDGEWISE CONSULTING, San Jose, CA 1997 - 2002


Built the ShadowChaser3D and Animailer applications. Improved the 3ds max VRML97 exporter. Added EXIF support to JPEG library. Assisted client with workflow planning and tool set-up for web site development. Developed a custom Windows application to demonstrate the prototype of a new peripheral device. Conducted a feasibility study for ShadowChaser 3D. Built web sites.

SILICON GRAPHICS, Mountain View, CA 1986 - 1997

Member of Technical Staff — Cosmo Software (1996-1997)

Developed streaming VRML animation technology. Liaison to MPEG, responsible for converging VRML and MPEG-4 specifications. Researched future uses of VRML especially for multi-user experiences and produced report compiling ideas. Founded VRML Consortium’s Color Fidelity and Streaming working groups.

Member of Technical Staff — Collaborative Tools Group (1992-1996)

Designed InPerson, a desktop video conferencing application. Implemented the user-interface using C++/Motif and integrated the video, audio and whiteboard components, drawing on real-time multi-threaded programming experience. Directed whiteboard implementer in its UI design.

Member of Technical Staff - Digital Media Group (1990-1992)

Led a team of four senior engineers in development of an ahead-of-its-time digital media software architecture. Member of group that designed SGI Audio Library. Managed digital media tools software release.

Engineering Manager - Window Systems Group (1988-1990)

Managed seven-person team developing and releasing 4Sight, the window system for IRIX.

Member of Technical Staff - User Interface Group (1986-1988)

Ported NeWS to both 68020- & MIPS-based workstations. Developed NeWS into 4Sight, a replacement for SGI’s proprietary window system. Experimented with pie menus throughout the system.

SABER TECHNOLOGY, San Jose, CA 1985 - 1986

Staff Software Engineer

QUBIX GRAPHICS SYSTEMS, Saratoga, CA 1982 - 1985

Senior Systems Software Engineer

Open Source Software Contributions

KTX Software

Created toktx, a tool for creating KTX format texture files, and libktx, a library for loading them. The library has loaders for OpenGL {,ES} and Vulkan.


With one other person, added support for creating Vulkan surfaces on SDL windows. Supports all platforms for which surface extensions are defined in vulkan.h, including iOS and macOS.

Added a hint that requests loading an OpenGL ES library, overriding the the default behaviour of creating an OpenGL ES context on the OpenGL driver.

Standards Contributions

Khronos Group

Founding member of the OpenGL ES WG. Numerous contributions to the OpenGL ES, OpenGL, WebGL and EGL specifications and conformance tests. Editor of the KTX file format specification and creator of libktx and toktx.

Java Community Process

Expert Group member and contributor to both JSR 184 & 297 (M3G
1.0 & 2.0). In particular, author of the k-DOP-based collision detection features in JSR 297. Received award from the JCP for Most Innovative J2ME JSR, 2003. EG member and contributor to JSR 239 (Java binding for OpenGL ES).


Co-author of ISO/IEC 14496-21:2006 Information technology — Coding of audio-visual objects — Part 21: MPEG-J Graphics Framework eXtensions (GFX). See my co-author’s description.

Inspired the 3D Graphics Coding group to port their mesh compression tools to Javascript and WebGL. Some interim results can be seen here. The raptor is a good example.


Publications and Teaching


未来の画像プラットフォームにおける先進的3Dグラフィックスをどう活用するか (How to Make Practical Use of 3D Graphics in the Future Imaging Platform?), Advanced Imaging Seminar, The Imaging Society of Japan, June 2013.


Mobile 3D Graphics tutorial, Eurographics 2008


Big Games, Small Screens, article in ACM Queue Magazine Vol 5, #9, ACM, November 2007. With Paul Beardow and David Brittain.


The Mobile 3D Ecosystem course, Siggraph 2007.


Developing Mobile 3D Applications with OpenGL ES and M3G tutorial, Eurographics 2006.


Developing Mobile 3D Applications With OpenGL ES and M3G course, Siggraph 2005.


User Interface Choices for Desktop Video Conferencing, DVC Conference, 1994.


An Introduction to Window Systems course, Siggraph 1988-1990.


The NeWS Book, James Gosling et al, Springer-Verlag, July 1989. Chapter on porting.


The UNIX System and Interactive Graphics, UNIX World, October 1984.


Member, Association for Computer Machinery, ACM Siggraph, ACM Sigmobile

Member, Institution of Engineering and Technology


MS, Electrical & Computer Engineering, Clarkson University, Potsdam, NY, USA

BSc (Hons), Electrical & Electronic Engineering, University of Newcastle Upon Tyne, UK

Languages (Human)

  • English

  • 日本語

  • Un peu français