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3 Stage 3 of 6

Bake Maps and UV Cards

Bake visible Hair Layers into 13 texture channels and generate the UV Card topology that card editing, mesh export and grooming all depend on.

Stage 3 is the hinge of the pipeline. It turns the procedural strands you built into flat texture maps, and — in the same pass — into the card geometry that carries them.

Baking

Run a bake

The baking engine renders your visible hair layers from directly above, unlit, into flat anti-aliased map channels. Use Quick Bake for defaults, or open the Bake panel to choose channels, resolution, margins and dilation.

Advanced Bake Settings. Map selection is on the left, resolution and margin in the middle, and the UV Cards checkbox is the one that decides whether Stage 5 is possible at all. · select to enlarge

  1. Check what is visible

    Only visible layers are baked. Confirm the Hair panel hierarchy shows exactly the layers you want captured.

  2. Set resolution and margin

    Pick the output resolution your plan allows and set the canvas margin — 0.5 cm by default.

  3. Enable UV Card generation

    Check Generate UV Cards Document if you intend to edit card topology, export mesh geometry, or groom cards on a head. It is far cheaper to tick it now than to re-bake later.

  4. Bake

    Click Quick Bake or press Ctrl+B to render all 13 channels and build the UV Cards document.

UV Cards

Generate UV Cards

With Generate UV Cards Document enabled, the engine builds polygon card strips that match your visible hair bundles. That topology is what the UV Cards workspace edits, what mesh export writes, and what Stage 5 grooms.

Soft-editing a UV card vertex. Neighbouring vertices follow the one you drag, which keeps the card's flow intact instead of creating a kink. · select to enlarge
The UV workspace toolbar: selection, edit, soft edit, draw, guides and mesh export, left to right. · select to enlarge
The UV edit view with card geometry and its control points visible. · select to enlarge
Card Shape controls. Segment counts decide how much the card can bend; padding decides how much of the baked atlas rectangle it samples. · select to enlarge
Guide-mapping controls, which tie a card back to the strand bundle it came from. · select to enlarge
Drawing a rectangular card slot by hand, when the generated layout needs an addition. · select to enlarge

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UV Card Topology & Resampling Parameters
Parameter Range / Default Technical Effect
Length Segments 2 to 32 (Default: 16) Longitudinal polygon division count per card strip along hair length.
Width Segments 1 to 12 (Default: 1) Transverse polygon division count across card width.
Padding Coverage 0.0 to 1.0 (Default: 0.1) Expands card UV boundaries relative to baked strand atlas rectangles.
UV Orientation 4 Modes Controls card V-direction: RootToTip (V=0 root, V=1 tip), TipToRoot, LeftToRight, RightToLeft.
UV Channels Dual UV Sets UV0 maps card normalized geometry; UV1 samples exact sub-rectangle atlas bounds.
Channel reference

13 bake channels

HairStorm generates up to 13 offscreen orthographic bake maps aimed at game-engine hair shaders.

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Complete 13 Bake Map Channel Reference
Bake Map Channel Format / Encoding Shader & Pipeline Utility
Albedo RGB Color Base color gradient along strand length from root to tip.
Roughness Grayscale Specular roughness response across strand surfaces.
Normal RGB Encoded Bake-canvas encoded surface normals: (x, -z, y) mapped to [0, 1].
Direction RGB Vector Tangent flow direction vector for anisotropic hair shading.
Height Grayscale / Depth Normalized height/depth gradient from canvas base.
ID RGB Color ID Root group color mask for multi-material card blending.
Alpha Grayscale Mask Strand opacity mask (never dilated; optional Gaussian smoothing).
RootTip Grayscale Ramp Vertical strand UV.y gradient (0.0 at root, 1.0 at tip).
Tangent RGB Vector World-space tangent vectors for specular highlights.
Bitangent RGB Vector World-space bitangent vectors for hair frame transport.
Thickness Grayscale Strand width profile & thickness map for transmission shading.
Ambient Occlusion (AO) Grayscale Dynamic realtime GPU ambient occlusion derived from height & normal passes.
Strand ID Grayscale ID Stable per-strand grayscale ID for per-hair color variation.
Settings

Bake settings

Post-process readback options that stop mipmap edge bleed and soften alpha masks.

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Texture Bake Configuration Settings
Setting Range / Default Description & Workflow Effect
Bake Resolution 2K / 4K / 8K Output texture size (2048px Trial, 4096px Personal/Pro, 8192px Studio).
Texture Dilation 0 to 64 px (Default: 32 px) Extends edge texels outwards into empty space on non-Alpha maps to prevent background color bleed during engine texture mipmapping. Alpha map is never dilated.
Canvas Margin 0.0 to 5.0 cm (Default: 0.5 cm) Adds physical padding around auto-fit canvas bounds before orthographic rendering.
Smooth Alpha On / Off (Default: Off) Runs a 1-pass 3×3 Gaussian blur on the Alpha mask after pixel readback to soften MSAA staircase edges for production bakes.
Validate

Confirm the output

Inspect the generated channels in the Texture Viewer, then switch to the UV Cards workspace and check the atlas packing and strip layout. Both need to look right before you groom or export — a bad bake propagates into every asset after it.