Kythera's Shader + Addon

blender addon that slaps Kythera's ZZZ shader on zenless zone zero models n carries all the textures over so u dont have to plug 40 image nodes by hand lmao

works on

• raw zzz fbx exports, the ones w MAT_<Name>_UI materials n a Materials folder full of json
• models already set up w the hoyoverse setup wizard (ZZZ Shader Body, ZZZ Shader Face etc)

needs blender 5.0 or newer n Kythera's ZZZ Shader blend file (not included, get it from Kythera)

1. download kythera_shader.py from releases
2. Blender > Edit > Preferences > Add-ons > Install from Disk, pick the file
3. tick it on
4. find it in the 3D view sidebar (N) under the Kythera tab

thats it. it updates itself from now on

1. click Import Kythera's Shader once n pick the kythera blend. it remembers it forever after this
2. click Import Raw ZZZ FBX n pick the character fbx
3. done. body hair weapons eyes face all converted, sun n face stuff set up

just click Import Kythera's Shader. every mesh in the scene gets converted

Reapply To New Objects converts anything new in the scene w the cached shader

• swaps every zzz material for Kythera's body or face shader
• finds _D _M _A _N for each material, from the json files if they exist, otherwise by matching texture names
• _D is sRGB, _M _A _N are Non-Color (they're data maps, not colors)
• gives every face its own lightmap (from the json on raw fbx, from the old face material on setup wizard models) so male n female faces both look right
• face _D is set to premultiplied alpha
• the eye mat gets split using the vertex colors zzz bakes into the eye mesh (same split the setup wizard does):
  • irises, pupils n sparkles get the face shader
  • the shadow strip over the eye becomes Eye Shadow: face _D into a Transparent BSDF, thats it
  • the soft gloss over the iris becomes Eye Highlights. it uses Kythera's ZZZ Eye Highlights from the shader blend if its in there, otherwise a built in one (face _D alpha into a color ramp mixing transparent n the face _D color)
• adds a Kythera Sun. the toon shading n the face shadow both follow it
• adds a Head Direction empty parented to the head bone so the face shadow moves w the head
• adds a Kythera Face Vectors geo nodes modifier to the face that feeds the sun n head direction to the face shader
• deletes the HairShadow stencil meshes, they r only useful in game

two buttons in the Outlines box, both inverted hull, outline color is the _D map darkened like the setup wizard does it

• Add Outlines works like the setup wizard: geo nodes w Merge by Distance on body meshes, Solidify on the face
• Add Fast Outlines is the light version. seams get welded once when u click the button instead of every frame, n the hull comes out as an instance so blender doesnt have to copy the whole mesh (vertex groups n all) every frame. on raw Miyabi its about 2x cheaper to pose/playback than the wizard style one. width follows the vertex color red channel so eyes n mouth dont get outlines
• every mesh w a material gets outlines, not just the converted ones
• the body mesh is the boss. its outline modifier has Thickness, Outline Color, Flat Color (0 = darkened texture, 1 = ur Outline Color) n Screen Space, n every other mesh's outline is driven from it. turn the body's outline modifier off n they all turn off. the same settings show up in the Outlines box
• Remove Outlines takes everything back off

on by default. on startup it checks this repo's releases (every 12h max), downloads the new one n keeps a .bak of the old file. restart blender or hit Reload Add-on to use it

turn it off or change how often in Preferences > Add-ons > Kythera Shader

• Face shadow on the wrong side: the addon assumes ur character faces -Y when converting. rotate the Head Direction empty 180 on Z if u converted it facing somewhere else
• No shadows: Set world background color to black or use the camera ray technique to keep a custom background. It's not a nice fix but if there are solutions to this, let me know.
• Skin looks yellow/weird brightening around light/shadow boundary: turn off SSS. This will be reworked in the next shader update
• Face fully lit: sun is in front of the face, thats normal for this shader. rotate the sun to the side
• Textures missing on raw fbx: textures need to be in the same folder as the fbx (or a Textures folder next to it)
• Want a newer kythera blend: clear cache, import again, pick the new file

• The shader is actually two shaders: one for the face and one for the body.
  • The body shader allows types of light sources other than Sun (Area, Point, Spotlight). It also allows for multiple lights to affect the body shader, which can get messy quickly so just use light/shadow linking if necessary
  • the face shader strictly follows the sun light direction, meaning a point light will NOT affect the face (you might notice some slight hair shadows but this will be fixed). This will work even if the sun is hidden, so you can definitely use it as just a light direction while keeping it hidden from renders, and use other lights to illuminate the rest of the body.

1. bump bl_info["version"] in kythera_shader.py
2. make a release w the same tag, (1, 7, 0) → v1.7.0
3. attach kythera_shader.py
4. if the tag n bl_info dont match the updater keeps nagging forever lol

• shader by Kythera
• addon by Jideeh