An XAF file is most often an XML animation file used in 3D pipelines—most notably by 3ds Max or Cal3D—and it focuses on motion data only, so although you can view it in a text editor filled with tags and numeric values for keyframes, timing, and per-bone transforms, nothing animates there because it’s pure mathematical description, holding animation tracks but not the actual model, and expecting the target software to already have a matching skeleton.

The act of "opening" an XAF is effectively importing it into the proper 3D system—such as Autodesk 3ds Max or a Cal3D-ready workflow—and incorrect bone hierarchies or proportions can cause the animation to fail or deform, so a quick identification trick is scanning the beginning of the file for hints like "Cal3D" or 3ds Max/Biped/CAT to confirm the intended software and the matching rig required.

An XAF file is focused on animation data rather than complete character assets, typically holding timelines, keyframes, and tracks that drive bone rotations or other transforms tied to specific bone names or IDs, often with interpolation curves for smooth motion, and depending on the pipeline it may store one animation or many while always defining skeletal movement over time.

An XAF file usually doesn’t carry geometry, textures, shading materials, or scene elements, and often doesn’t define a complete skeleton on its own, expecting the target software to have the proper rig in place, which makes the file function more as choreography than a full animation, and when the destination rig differs in bone naming, structure, orientation, or proportion, the animation may refuse to apply or appear misaligned, twisted, or offset.

For more info regarding file extension XAF take a look at the website. To identify what kind of XAF you have, the quickest approach is to treat it like a self-describing clue file by opening it in a plain text editor such as Notepad or Notepad++ and checking whether it’s readable XML, since visible tags and words point to an XML-style animation file, while random symbols might mean it’s binary or misnamed, and if it is readable, scanning the first few dozen lines or searching for terms like Max, Biped, CAT, or other rig-related wording can hint at a 3ds Max–style pipeline along with familiar bone-naming patterns.

If you spot explicit "Cal3D" text or tags that indicate Cal3D-style animation clips and tracks, it’s likely a Cal3D XML animation file that expects matching Cal3D skeleton and mesh assets, whereas lots of per-bone transform tracks and keyframe timing tied to identifiers resembling a 3D DCC rig suggest it came from 3ds Max, and game-runtime-like clip structures hint at Cal3D, with external context—such as bundled Max assets or Cal3D companion files—serving as additional clues, and checking the first lines for keywords being the most reliable confirmation.