Gmax was a 3D modeling application based on Discreet's 3ds Max used by professional computer graphics artists. Whereas 3ds Max is a comprehensive modeling, animation, and rendering package with some secondary post-production and compositing features, Gmax is much more limited due to its singular intended use--game content creation. Tools and features rarely used or completely unrelated to creating 3D game models were removed (most if not all of the more complex rendering, materials, shaders, physics simulation, and some of the more advanced geometry tools, plus the rendering engine), leaving the core modeling, texturing, and basic animation rigging and keyframing capabilities.

Gmax can be expanded by "game packs", which feature customized tools with the purpose of creating and exporting customizable content to games and websites. As Gmax was bereft of its progenitor's rendering engine, game packs were typically required to provide such a feature for Gmax if deemed necessary (Maxis was the first company to write a dedicated renderer for their gmax gamepack, BAT--Building Architect Tool--for SimCity 4).

Cancellation

As of October 16, 2005 AutoDesk Media and Entertainment has discontinued Gmax. They no longer support Gmax. Instead, the company has decided to focus on 3D Studio Max. However the last version of Gmax is available for free to download from the official support website. Maya Personal Learning Edition, a similar 'mod builder' variant of Maya, is still active