Flatiron Usage Guide
Flatiron Usage Guide
Description
This guide covers all Flatiron settings for UV unwrapping, texture packing, and baking.
Flatiron supports all major 3dsMax renderer: Scanline, Arnold, Corona, V-Ray and FinalRender.
Unwrap Parameters
Control how Flatiron flattens your 3D mesh into a 2D UV map.
| Setting | Description |
|---|---|
| Unwrap Mode | Choose the unwrapping method: • Organic – Best for irregular, curved shapes (characters, animals, foliage). • Hard Surface – Ideal for architectural and mechanical objects. Avoids overly fragmented results. • Pack Existing – Uses your current UV charts, repacks them without overlaps, but creates no new unwrap. Requires existing UVs. • Keep Existing – Leaves all UV charts exactly as they are, only merging them. You must ensure no overlaps. Requires existing UVs. • Projection Unwrap – Unwraps based on a camera or object view. Great for assets seen from a fixed perspective. |
| Target Channel | The UV channel where the new map will be stored. |
| Source Channel | The UV channel used as input for Pack Existing, Keep Existing, or seam data (if Keep Seams is on). |
| Texture Stretch | Allowed distortion (0 = none, 1 = unlimited). Lower values preserve shape but may create more charts. |
| Gutter Padding | Distance (in pixels) between UV charts. Prevents color bleeding. |
| Texture Width / Height | Output texture resolution in pixels. |
| Aspect Ratio | Locks the width/height ratio. |
| Preview | Shows a UV template before applying. Helps you test settings without adding a modifier. |
| Unwrap | Unwraps selected objects or named selection sets. You can add a group name above the button. |
Some UI options are only available in specific Unwrap Modes.
Advanced Unwrap Parameters
UV Packing Engine
Optimize how UV charts are arranged in the texture.
| Setting | Options & Description |
|---|---|
| Type | • Classic – Legacy mode (slower, less efficient). Only for compatibility. • Efficient – Default. Great balance of speed and packing density. • High Quality – Slower, but packs charts tighter for better texel density. |
| Rescale UV Charts | When ON, charts are scaled by surface area → even pixel distribution. OFF keeps original chart sizes. |
| Pre-Rotate | Rotates each chart to its best starting orientation. Works even if rotation options below are OFF. |
| Rotation | Adds extra rotation angles (e.g., 90°, 180°) to improve packing. Smaller angles = better packing but slower. |
| Full Rotation (Ø) | Includes exact 180° rotations. Slightly better packing but slower performance. |
Unwrapping Mode (Seams)
| Setting | Description |
|---|---|
| Keep seams | Preserves your manual seams. Essential for controlling where cuts happen. |
| Cut Grooves | Adds seams along concave edges (grooves). Angle threshold = minimum corner angle to cut. |
| Cut Ridges | Adds seams along convex edges (ridges). Angle threshold = minimum corner angle to cut. |
Projection Unwrap (Camera-Based)
| Setting | Description |
|---|---|
| Pick Camera | Any scene object works, but a Camera is best. Uses the object’s local -Z axis as view direction. |
| View Angle | Surfaces within this angle (0–180°) from view direction are kept. 180° = everything visible from that point. Smaller = discards sides/back. |
| Tolerance | Positive = includes near-backfacing polygons. Negative = excludes visible polygons if they’re too angled. |
| Orthographic | Ignores perspective. Uses orthographic projection. Disables View Angle. |
Unwrap to Multiple Maps
Instead of one UV map, distribute objects across several maps.
| Setting | Description |
|---|---|
| Fixed Number | Enter a number (default = 1). Objects are automatically split across that many maps. |
| Selection Sets | Each selected set gets its own map. Objects in multiple sets only go to one map. |
Preview only shows one map at a time when using multiple maps.
Baking
Turn your UV map into a rendered texture.
| Setting | Description |
|---|---|
| Baked Map File | Output folder (default = user’s renderassets). |
| Renderer Settings | Opens the default render dialog (Scanline, Arnold, V-Ray, etc.). |
| Overlap | How much the render extends beyond UV chart edges. Helps hide seams. Must be less than Gutter Padding to avoid overlap with other charts. |
| Single Pass Baking | Toggles between single-pass (fast, all objects at once) and multi-pass (slower, per-object). See Texture Baking Modes chapter. |
| Target Material | Material that receives the baked map. If no map slot is assigned, no material is created. |
| Make self-illuminating | Makes material 100% self-illuminating. Useful for baked lighting/shadow maps. |
| Add Shell | Creates a Shell Material with original + baked materials. Lets you toggle between them. |
| Overwrite | Replaces the original material directly (no shell). |
| Choose Bake Elements | Opens dialog to select what to bake (diffuse, normals, etc.) and their settings. |
| Add group name to textures | Adds group name as prefix to avoid overwriting files. |
| Single | Bakes only the current frame. |
| Range | Bakes a sequence of frames (animation). |
| Bake Selected | Bakes chosen elements for the current object group. |
| Remove Selected | Deletes the selected object group and its unwrap settings. |
Bake Elements Dialog
Control exactly which texture maps to render.
| Control | Description |
|---|---|
| List (top) | Shows all active bake elements. |
| Add / Remove | Add or remove elements from the list. |
| File name | Base name for the output texture. |
| Map slot | Which material slot (Diffuse, Normal, etc.) to assign the map to. NONE = render but don’t assign. |
| Background | Color for empty areas (no UV charts). Usually irrelevant if padding is correct. |
| Width / Height | Resolution of this specific bake element (can differ from main texture size). |
Below these, you’ll find element-specific controls (e.g., for Normal maps: flip green channel, etc.).
Shells (Material Management)
Quickly switch between original and baked materials.
| Setting | Description |
|---|---|
| Shell Switcher | Radio buttons to change viewport/render display mode for selected objects (like the Material Editor’s Shell rollout). |
| Clear Shells | Removes shell materials from selected objects. |
| Keep Baked | After removal, keeps the baked material. Discards original. |
| Keep Source | After removal, keeps the original material. Discards baked. |
Network Rendering
Use Backburner to distribute baking across multiple machines.
| Setting | Description |
|---|---|
| Network render | ON = use Backburner. OFF = local rendering only. |
| Network manager | Hostname or IP of Backburner Manager. |
| Port | Backburner Manager port number. |
| Network output folder | Shared network folder for temporary Flatiron data. |
| Netrender Status | Shows current job status from Backburner. |
| Manual Merge | Use if a completed job wasn’t auto-detected. |
See the Network Rendering chapter for full setup instructions.
Options
Save, load, and reset your Flatiron preferences.
| Setting | Description |
|---|---|
| Create Selection Sets | Creates named selection sets (fi_*) from existing unwrap groups. |
| Single set for multiple maps | If ON, one selection set per group even if spread across multiple maps. |
| Save Settings | Export current settings to a .ini file. |
| Load Settings | Import settings from a file. |
| Save Default | Make current settings the new default. |
| Reset Default | Restore factory defaults. |