FBX

FBX is an Autodesk-owned file format used to move 3D scenes from one program to another. Besides polygon geometry, an FBX file can hold material assignments, texture paths, cameras, lights, the object hierarchy and animation. It can be saved as binary or as text.

FBX in architectural visualization

FBX earns its place when a model leaves the modeling tool and heads for a real-time engine or an animation package. A building modeled in SketchUp or Revit can travel to 3ds Max, Blender or Unreal Engine as FBX. Because objects arrive with their names and groupings, reworking materials and setting up cameras goes much faster than with a flat mesh.

What to watch for

• Units and scale: if source and target use different units, the model can show up a hundred times too big or too small.
• Up axis: some programs treat Z as up, others Y. A model lying on its side is usually this.
• Textures: unless textures are embedded, the target program looks for them in a separate folder and the paths can break.
• Normals: flipped faces and smoothing can get scrambled on the way, so check them before rendering.

For a side-by-side look at which programs handle which formats comfortably, see software used in architectural 3D modeling.