# Ep.8 — FBX Export Options (Detailed Options Guide for Engine Import)
https://youtu.be/uXCT5PicgQU?si=iM07m4TMUj1vHdBr
> **Summary**: The **upper area** of the FBX options panel exposes 3ds Max's built-in FBX export controls; the **lower area** contains Fast-Ref's proprietary Namespace removal, root alignment, and dynamic filename generation features. Save your configured options as a Preset for team-wide sharing.
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## 1. The Core Mechanism of Option Control
Fast-Ref's exporter panel stores configured settings as **Preset** files on disk, and both the single exporter and the overnight **Batch Tool (EP09)** are completely governed by the same preset — keeping output deviation at zero.
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## 2. 3ds Max Default FBX Control Area (Upper)
These options connect to the FBX SDK options provided by the 3ds Max engine itself. Here is a practical-tips-focused summary.
| Option | What It Actually Does | 💡 **Practical Guide & Tips** |
|--------|----------------------|-------------------------------|
| **Animation** | Whether to embed keyframe animation data in the FBX | Obviously must be **On** when exporting animation clips. But when first registering the character's Skeletal Mesh in the engine, turn this off and export a clean T-pose at frame 0. |
| **Skin** | Whether to include skin binding information (deformation data) | - **First mesh registration**: **On**
- **Animation clips only**: **Off**
👉 Once the character mesh is already in the engine, turning off Skin when exporting animation clip FBXs reduces file size by 10x and speeds up export dozens of times — a powerful practical technique. |
| **Shape** | Whether to include Blend Shape / Morph data for facial expressions | Always **On** for main characters with facial animation. |
| **Bake Animation** | Bake keys at every single frame regardless of original frame rate | Keeping **Bake On** is the production standard for preventing animation squishing caused by engine physics interpolation conflicts. |
| **Smooth Groups** | Store smooth shading information for 3D mesh faces | Always **On**. Accidentally turning this off and importing into the engine causes the beautiful character to come out **looking like a Minecraft character — blocky and angular** — a total disaster. |
| **Texture Embed** | Force-embed texture image sources as binary data inside the FBX file | Always **Off**. Enabling this causes dozens of megabytes of images to tangle inside a single FBX, making file size spiral out of control. Manage paths as relative paths inside the 3D scene only. |
| **Up Axis** | Set the 'sky direction' axis the game engine uses | - **Unreal Engine**: **Z-up** (matches 3ds Max)
- **Unity Engine**: Pressing the Unity preset button auto-adjusts to **Y-up** |
| **Units** | Match the scale unit inside the engine | 3ds Max defaults to cm scale. For Unity (prefers m units), you must manually verify the scale factor via the Unity preset to avoid shrink/inflate bugs. |
| **File Version** | FBX export file format version | Standardising on **FBX 2020** — the most error-free and stable format in the current industry — is recommended. |
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## 3. Fast-Ref Exclusive Export Control Area (Lower)
These production-focused automation features are available only within Fast-Ref.
### ✂️ Remove Namespace
Forcibly strips the prefix from names like `Mable_A:L_Hand` (added temporarily for multi-character placement), so the engine importer receives only the original clean bone name `L_Hand`. No need to worry about retargeting breaking inside the engine.
### 🎯 Reset Root (Force-Freeze Root Bone at Origin)
Even if the character has animation where it runs forward through world space, there are times when the **root bone must be output locked at its origin position and rotation (0,0,0)** for engine root motion computation or binding rules.
- Recognises a specific root bone name, force-holds it at the origin, and optionally applies a correction rotation (e.g. 90 degrees on Z) to align the character's forward direction.
- 🚨 **Critical Warning**: Because this feature temporarily computes the character's scene coordinates at export time, **the working `.max` file must be closed without saving immediately after FBX extraction** to prevent scene animation corruption. This is a tip leads must drill firmly into their artists.
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## 4. Dynamic File Naming Rule Design
Instead of manually typing each output FBX filename, define a rule using the dynamic variables below to auto-generate filenames.
* `[Original File Name]`: Current scene max filename
* `[Namespace]`: The unique name assigned to that character
* `[Date]`: Today's date auto-stamp
* `[Auto Namespace / Index]`: If there is only one character in the scene, exports with the clean original name. **The moment two or more are detected, automatically splits into names like `FileName_Yuna`, `FileName_Mila`** — an impressively smart automation.
### 🏷️ Create Rigging Data (Export to Selection - ES Tag)
Rather than grabbing the entire viewport, this reads the **Selection Set name** (e.g. `Export Body`) registered by the rigger during the character master setup, and precisely filters to export only the mesh and skinning weight data. If the syntax is incorrect, a red error mark appears on the right side of the panel for easy identification and correction.
### 📁 Create Subfolder Per Max File
- **Checked On**: Automatically creates subfolders named after the working scene, useful for cinematic shots where many characters are interleaved.
- **Checked Off**: Recommended for cleanly outputting a single character's motion clips (Run, Walk, Idle) in a flat structure.
