Atlas and Baking

The Atlas & Bake Zone panel turns your strands into texture maps. Work through its sections from top to bottom: frame the zone, pick the render settings, choose the maps, and bake.

Atlas Plane

Option	Layout
Flat (XY) (default)	Strands grow along +Y and the sheet faces up (+Z). The bake camera looks down from above.
Upright (XZ)	Strands grow along +Z and the sheet faces front (+Y). The bake camera looks from the front.

Choose Upright if you prefer working in front view. Changing the plane rebuilds every bstrand.

Bake Zone

The bake zone is the rectangle that becomes your atlas. It is outlined in yellow in the viewport.

Image coming soon

The Bake Zone section, and the viewport through the bake camera with the yellow zone around a row of strands.

Control	What it does
Center X / Y	Where the zone’s centre is.
Width / Height	The zone’s size in metres.
Aspect	The texture’s shape (see below).
Resolution	Pixels on the zone’s long side: 256, 512, 1024, 2048, 4096 or 8K.
Output	The size the maps will be written at, for example 4096 x 2048 px.
Fit Zone to bstrands	Wraps the zone around every visible bstrand, with a 2% margin (untick Add 2% Margin in the Adjust Last Operation panel for an exact fit).
Eye beside Fit Zone	Shows or hides the yellow outline.
Edit Bake Zone	Drag the zone directly in the viewport (see the hotkeys below).
Update Bake Zone	Creates or updates the bake camera, BStrands_AtlasCam, and looks through it.

When you change Resolution, Aspect, Width or Height, the scene’s own Resolution X / Y (Properties ▸ Output) update to match.

Aspect: Power of 2 or Free

Aspect	Texture size	What Fit Zone does
Power of 2 (default)	Standard game texture sizes such as 4096 × 4096, 4096 × 2048 or 4096 × 1024.	Snaps the zone to the nearest of 1:1, 2:1, 4:1…, growing it slightly. A row of strands at 1.98:1 becomes exactly 2:1.
Free	Follows the zone exactly: a 2.2 × 1.4 m zone at 4096 gives 4096 × 2607.	Hugs the strands.

Note

Under Power of 2, if you type a Width and Height that aren’t a power-of-two shape, the texture uses the power-of-two shape that still contains the zone, and the camera sees a little past the yellow outline on the short side. Press Fit Zone to bstrands to snap it, or switch to Free.

Edit Bake Zone hotkeys

Key	Action
LMB drag	Drag a corner or edge to resize; drag inside to move
Shift + drag	Resize from a corner while keeping the aspect ratio
Space	Make the zone square (1:1)
F	Fit to the visible bstrands
Enter	Confirm
Esc or RMB	Cancel and put the zone back

Render

Control	What it does
Engine	The engine the maps are baked with: EEVEE or Cycles.
Device	Cycles only: bake with GPU + CPU, GPU or CPU.
Samples	Anti-aliasing samples per map. Below 4 there is no edge antialiasing; 16–32 is the useful range.
Preview Bake Look	Shows a map’s flat, unlit look on the strands in the viewport. Choose which map in the menu beside it.

The bake always runs in a separate, unlit scene, so your lights, world and render settings are never touched.

Tip

For the Ambient map, Cycles is faster than EEVEE from about 1K and up. For the other maps the two engines give nearly identical results.

Curves

Blender’s own curve render settings, for the engine you bake with. The bake uses them too.

Engine	Shape options	Recommendation
EEVEE	Strand (hairlines), Strip (flat ribbons), Cylinder (round tubes), plus Additional Subdivision	Cylinder
Cycles	Rounded Ribbons, 3D Curves, plus Subdivisions	3D Curves

Flat ribbons swap in hard steps where strands overlap, and those steps bake into the maps. Round tubes meet cleanly and bake no slower. Activate Curve-BStrands sets the recommended shape for you.

Texture Bake

Image coming soon

The Texture Bake section with the map list, options and the Bake button.

The maps

Each map row has a checkbox (bake this map), an alpha toggle and a Show Map button that opens the baked file in an Image Editor. The All / None buttons at the top switch every map, or every alpha toggle, at once.

Map	What it holds	Background without alpha
Albedo (Color)	The root-to-tip gradient multiplied by painted colour	Black
Alpha (Opacity)	Strand coverage: white hair on black	Black
Specular	Specular level, masked by the strands	Black
Depth (Height)	Position through the sheet: 0 at the back, 1 at the front	Black
Normal	Surface normal	Neutral normal (flat blue)
Root-Tip	0 at the root, 1 at the tip	Black
Direction (Flow)	Which way each strand runs	Neutral flow
ID	A random flat colour per strand	Black
Ambient	Ambient occlusion, ray traced by the chosen engine	White
Translucency	Translucency level, masked by the strands	Black

Maps bake opaque by default: strands over a solid background, which is what most pipelines expect. Turn on a map’s alpha toggle to write it with a transparent background and an alpha channel instead.

Output options

Control	What it does
Normal Format	OpenGL (+Y up) for Blender, Unity, Godot and Substance’s OpenGL export. DirectX (−Y up) for Unreal Engine, 3ds Max and Substance’s DirectX export. If hair looks lit from the wrong side in your engine, switch this.
Antialiasing	Smooths strand edges; the number beside it is the filter width in pixels. Turn it off for hard, aliased edges, for example on an ID map.
16-bit Data Maps	Writes Depth, Normal, Direction and the other data maps at 16 bits, so they don’t band. Albedo stays 8-bit. Needs PNG, TIFF or OpenEXR.
Alpha Threshold	Above 0, drops faint coverage so thin strands don’t bake as grey haze. Below 0, makes faint strands read more solid without growing the silhouette.
Fix Dashed Gaps	Fills small gaps between lit pixels, so sub-pixel strands don’t bake as dotted lines. 1–2 is plenty. It never grows the silhouette.
Bleed	Pads the baked colour outward by this many pixels, so texture filtering never samples empty space at strand edges. The Alpha map is never padded.

Specular and Translucency

Control	What it does
Level	The base value of the map.
Shape	Shades each strand as a tube. Specular gets brightest along the centre of each strand; Translucency brightest at its edges. At 0 the map is flat.
Root-Tip	Fades the map along the strand. Positive dulls (Specular) or darkens (Translucency) the roots; negative the tips.
Variation	Gives each strand its own value.

These settings also shade the strands in the viewport, so you can judge them before baking.

Ambient Occlusion

Control	What it does
Distance	How far occlusion reaches. Fit AO Distance sets it from the bstrands: half their thickness, where the effect stops growing.
Strength	Deepens the occlusion. Hair occlusion is naturally subtle; raise this for more contrast.
Rays	Cycles only: rays per sample. Leave it low and raise Samples instead, which improves quality more for the same time.

Bake

The line above the button shows the strand width, in atlas pixels, of the thinnest bstrand. Under about 1.5 px strands can’t fill a pixel and bake as dotted lines: raise Thickness or Resolution.

1. Save your .blend file, so the default output folder next to it exists.
2. Click Bake N Map(s). A progress bar in the viewport shows each map; Esc cancels.
3. Click Show Map beside a map to inspect it.

Maps are written to the output folder set in Export & Save, named <Name Prefix>_<map>.<format>, for example BStrands_normal.png.

If you bake again while cards or the preview card are showing the atlas, click Reload Baked Maps so Blender picks up the new files.

Tip

High resolutions take time. As a guide, on the machine the add-on was tested on, one map takes about a minute at 8K, and Bleed adds about 45 seconds more per map; at 4K Bleed adds about 12 seconds. A full ten-map 8K bake with Bleed can take around twenty minutes. The panel shows the padding cost at 4K and above. Bake at 1024 first to check your settings.