FilmBox (FBX)

What is FBX?

FBX (Filmbox) is a proprietary 3D interchange file format used across film, television, game, and VFX pipelines to move geometry, materials, cameras, lights, skinned characters, and animation between applications. It was created by Kaydara in the late 1990s and acquired by Autodesk in 2006, which continues to maintain the reference implementation as the free FBX SDK. FBX became the de facto interchange format for most of the 2010s because it handled the artist-facing content types (rigged characters, animation curves, keyframes) that earlier open formats (OBJ, Collada) either did not support or supported poorly.

FBX is a binary or ASCII file format built around a tree of node objects. Each node can carry transforms, geometry, deformers, materials, textures, animation stacks, and custom user properties. The format supports skeletal animation with full skinning weights, blend shapes for facial animation, multi-take animation stacks, embedded textures, and metadata for pipeline tracking. This coverage of production content is why FBX became standard for rig delivery between Maya, 3ds Max, MotionBuilder, and downstream game engines such as Unity and Unreal.

The format is under pressure from newer open standards. OpenUSD (originating from Pixar) has become the preferred interchange for VFX and virtual production pipelines. glTF (from the Khronos Group) has become the standard for web and mobile delivery. FBX remains the practical lingua franca for rigged character work, however, and continues to see broad tool support because so many existing pipelines depend on it.

What FBX carries

• Geometry (polygonal meshes, NURBS surfaces, patches)
• Skeletal rigs with skin cluster weights and bind poses
• Blend shapes (morph targets) for facial or object deformation
• Animation stacks with keyframe curves on any transform or property
• Materials and textures (with the option to embed textures inline)
• Cameras and lights with animatable parameters
• Custom properties for pipeline metadata

How FBX moves through a pipeline

A typical production use of FBX follows a common shape.

Author. A modeler builds a character in Maya, ZBrush, or Blender. A rigger adds the skeleton and skin weights. An animator produces the performance.

Export. The scene is exported to FBX with the animation baked into keyframe curves on the skeleton and blend-shape channels.

Consume. The FBX is imported into the downstream tool: a game engine for interactive playback, a real-time engine (Unreal, Unity) for virtual production, or an animation package such as MotionBuilder for further refinement.

Round trip. Notes flow back into the source application, ideally without breaking the round trip. FBX's biggest historical weakness has been unreliable round tripping between DCCs, which is one reason USD is displacing it for larger pipelines.

FBX versus adjacent formats

The interchange landscape has three formats in common use, each with its own sweet spot.

Most production teams work with a mix. A character might be rigged and animated in FBX, staged and lit in OpenUSD, and delivered to a web viewer or ad unit in glTF.

See also

OpenUSD — The open interchange format displacing FBX in larger VFX and virtual production pipelines.

glTF — The delivery-focused standard for web and mobile 3D.

3D asset pipeline — End-to-end workflow in which FBX still plays a role.

Additional resources

• Autodesk FBX SDK — Reference implementation and documentation for reading and writing FBX files.
• Autodesk FBX Review — Free viewer for inspecting FBX content.
• glTF versus FBX comparison (Khronos) — Context on when to choose glTF over FBX for delivery.