FBX (sometimes called Filmbox) is an interchange file format to move 3D animation data between software packages. It can contain entire scenes, including geometry, lights, cameras, NURBS, animation, and skinning.
Note
FBX format specification generally does not support animated objects with a changing number of points or changing connectivity, such as Houdini’s particle systems or fluids. It is only possible to export these types of objects by breaking them up into individual triangles (although still within one FBX object node).
To restore these objects to their original appearance when they are brought into other packages, weld their vertices together and set all appropriate mesh edges to smooth.
Note: To import these types of objects properly into Maya™, Maya’s FBX importer Use FBX Framerate in Maya option must be turned on.
Parameters ¶
Render
Begins the render with the last render control settings.
Controls…
Opens the render control dialog to allow adjustments of the render parameters before rendering.
Render with Take
Uses the settings in a particular take while rendering. Choose Current to use the current take when rendering.
Valid frame range
Limits the rendering of frames, when set to Render frame range or Render frame range only.
Render any frame
Allow the renderer to render any and all frames.
Render frame range
Only render the frames in the range set below, but allow the renderer to render other frames if they are referenced by in-range frames.
Render frame range only (strict)
Only render the frames in the range set below, and don’t allow the renderer to render other frames, even if they are referenced by in-range frames.
Export
Determines the node to start exporting at. Defaults to /obj, meaning all objects and subnetworks under it is exported.
If a node to be exported is a network, only its contents are written out, not the network itself.
Create Root for Subnet
Create an extra root for the Export node when it’s a subnetwork. This causes the exporting subnetwork node to be represented in the FBX file.
Output File
The file to save the geometry to (should end in .fbx).
Build Hierarchy from Path Attribute
Use a primitive string attribute for creating shape nodes in the output file. Each string value is treated like a path to a shape node that the primitive is created under. Intermediate nodes is created as needed with identity transforms. If the primitive is a packed primitive, then its parent node takes the primitive transform.
If the path value contains absolute filesystem prefixes, they are stripped. (eg. op:, http:, c:, etc)
Note
This parameter is only available when used from the Geometry context or
when the Export parameter is set to a 
Geometry object.
Note
Support for animation export is currently limited to only exporting primitive transforms and each primitive must have a unique path attribute value. There is no support for exporting to vertex caches nor changing geometry topology.
Path Attribute
The name of the attribute containing the path used for Build Hierarchy from Path Attribute.
FBX ¶
Export in ASCII
When on, the exported FBX file is in human-readable ASCII format. When off, the file is exported as a binary FBX file.
FBX SDK Version
Determines which version of the SDK to use to export the FBX file.
Vertex Cache Format
Determines which format vertex cache files is exported.
Maya Compatible (MC)
Maya’s native vertex cache format.
3DS MAX Compatible (PC2)
Vertex cache format compatible with 3DS MAX.
Export Invisible Objects
Determines how invisible objects are to be exported. This is convenient if a scene contains hidden objects that are highly complex but don’t need to exported.
As Visible Full Nodes
Each hidden object id represented as an appropriate type in FBX, and made visible. Processing time is the same as an object not hidden.
Axis System
Determines the axis system convention.
Y Up (Right-handed)
Right-handed Y Up convention (default): Up = +Y, Front = +Z, Cross = +X. Use this for Houdini, Maya Y-Up, MotionBuilder, and OpenGL.
Y Up (Left-handed)
Left-handed Y Up convention: Up = +Y, Front = +Z, Cross = -X. Use this for LightWave and DirectX.
Z Up (Right-handed)
Right-handed Z Up convention: Up = +Z, Front = -Y, Cross = +X. Use this for Maya Z-Up, and 3ds Max.
Current (Y-Up or Z-Up Right-handed)
Export using the current scene orientation preference.
Convert to Specified Axis System
When on, the FBX scene is converted from the current Houdini
scene orientation to one given in the Axis System parameter.
Convert Units
When on, the FBX scene is converted from the current Houdini system units to the native FBX unit of centimeters.
Conversion Level of Detail
Specifies the level of detail to use when converting non-polygonal objects to polygons. Higher values increase polygon subdivision level, lower values decrease it.
Detect Constant Point Count Dynamic Objects
When on, the exporter tries to detect animated objects that don’t change point count or point connectivity, and export them without breaking them into individual triangles. The same process is done to particle systems and fluids. This allows for RBD or cloth objects to be exported as a single, smooth object, while still allowing topology-changing objects to be exported.
This may fail if a object with changing point connectivity happens to have the same point count over all frames of exported animation. In these case, this option should be disabled.
Convert NURBS and Bezier Surfaces to Polygons
When on, the exporter converts all NURBS and Bezier surfaces to polygonal meshes using the level of detail below to determine mesh density. Otherwise, NURBS and Bezier surfaces is exported as NURBS.
Conserve Memory at the Expense of Export Time
Affects only objects exported with vertex caches. When on, internal vertex positions computed during export is discarded, not cached, resulting in reduced overall memory use. However, this increases the export time. When off, the exporter runs faster but uses more memory.
Export Deforms as Vertex Caches
When on, any geometry objects that contain Deform SOPs is exported as vertex caches with no weight information. When off, these nodes is exported as objects with skinning and corresponding weights.
Force Blend Shapes Export
When on, 
Blend Shapes SOPs found in geometry nodes are always exported, potentially losing information since any node modifying the geometry after the blend shapes is ignored. When off, blend shapes SOPs only exports if there’s no modification to the geometry after them.
Force Skin Deform Export
When on, Deform SOPs found in geometry nodes always exports, potentially losing information since any nodes modifying the geometry after the Deform is ignored. Only Bone Deform, 
Bone Capture and 
Capture Override nodes are currently supported. When off, these nodes only exports if no modification is done to the geometry after them.
Export End Effectors
When on, the additional end effector null nodes at the ends of each branch of a skeleton are included in the exported FBX file, allowing the FBX file to be reimported into Houdini correctly. When off, the additional end effector null nodes are not included in the exported FBX file. This can be helpful when trying to reduce the number of joints exported to an FBX file, but you will not be able to reimport it back into Houdini properly as the skeleton is effectively missing one joint/bone from each of its branches.
Embed Media
When on, any media files related to the scene (textures, sound, movies) are embedded in the exported file. When off, only relative references to the media files related to the scene are added to the exported file.
Compute Smoothing Groups
When on, the exporter computes smoothing group information from the normals of meshes in the scene.
Scripts ¶
A script command can be specified for execution at the various execution points. The expression language selected for the parameter determines whether this command are hscript or python statements.
Prior to execution, this node is automatically set as the global current node.
To run statements from a file instead, specify the path to the file with
either a .cmd extension (when the language is set to Hscript), or .py
extension (when the language is set to Python). Additional arguments to the
script can also be supplied, they will be parsed in a shell-like manner.
Pre-Render Script
Run this script before any rendering.
Pre-Frame Script
Run this script before each frame.
Post-Frame Script
Run this script after each frame.
Post-Render Script
Run this script after all rendering.
