How to use
- Copy the installation command and review the source package before installing it in your own agent environment.
- Check the source document for required tools, credentials and supported hosts.
- Describe your input and desired deliverable; review the output against the source material.
npx skills add https://github.com/roble3/cc-blender-skill --skill blender-uv-texturingBefore you start
- Installation does not include a model subscription, API allowance or permission to access your files.
- Repository stars and installation counts describe activity, not an independent quality or security test.
Original skill document
Rendered from the source repository. Headings, examples, code, tables, links, and referenced images are preserved.
MCP backend
Use when: Texture atlas/UV/baking/lightmap/decal work in Blender; any request involving texture fit, UV islands, project-from-view, texture packs, alpha decals, or baked maps.
Before the first Blender call, read ../text-to-blender/references/mcp-backends.md. Prefer official MCP for shared capabilities; preserve the selected backend for the whole task. Tool names in recipes are client/legacy examples: map them through that reference and its agent-host guide.
Blender UV Texturing
This skill fills the gap between “assign a material” and “the supplied texture pack actually fits the model.” It is mandatory for template/atlas-driven assets.
Decision tree
What does the texture represent?
├── Whole object from front/reference → Project-from-View style UVs from the validation camera
├── Atlas with separate parts → crop/map each part to its own UV island/rectangle
├── Repeating material → generated/object coords or tiled UVs
├── Face/expression decal → alpha material plane or projected UV island; no black background
├── Roughness/bump/normal map → Non-Color data, correct node type
└── Lightmap → separate UV/lightmap channel or optional multiply helper; not emissionNon-negotiable rules
- Image textures need a material node setup to render/export; viewport UV display alone is not enough.
- Basecolor/albedo = sRGB. Roughness, metallic, bump, normal, AO/lightmap = Non-Color.
- Atlas textures must be mapped by region. Never apply a full atlas to every mesh part.
- Alpha decals must use alpha-connected material settings (
BLEND,Alpha Hashed, orAlpha Clip) and a keyed/correct PNG. Do not leave black planes. - For GLB, keep to exporter-recognized nodes where possible: Principled BSDF with Image Texture inputs, UVs, normals, tangents.
- Validate with a checker texture or overlay render before final material tuning.
Recipes
Create front-projected UVs from world X/Z bounds
python
import bpy
def assign_front_projected_uv(obj_name, uv_name='UV_front_projected'):
obj = bpy.data.objects[obj_name]
mesh = obj.data
uv = mesh.uv_layers.get(uv_name) or mesh.uv_layers.new(name=uv_name)
mesh.uv_layers.active = uv
xs = [v.co.x for v in mesh.vertices]
zs = [v.co.z for v in mesh.vertices]
minx, maxx = min(xs), max(xs)
minz, maxz = min(zs), max(zs)
dx = max(maxx - minx, 1e-8)
dz = max(maxz - minz, 1e-8)
for poly in mesh.polygons:
for li in poly.loop_indices:
co = mesh.vertices[mesh.loops[li].vertex_index].co
uv.data[li].uv = ((co.x - minx) / dx, (co.z - minz) / dz)
mesh.update()Map a mesh to a rectangle in an atlas
Atlas rectangle is [u0, v0, u1, v1] in normalized UV coordinates. Use this after creating local 0–1 UVs.
python
def remap_uv_rect(obj_name, rect, uv_name=None):
obj = bpy.data.objects[obj_name]
layer = obj.data.uv_layers.get(uv_name) if uv_name else obj.data.uv_layers.active
u0, v0, u1, v1 = rect
for item in layer.data:
u, v = item.uv
item.uv = (u0 + u * (u1-u0), v0 + v * (v1-v0))
obj.data.update()Image texture material with correct color spaces
python
import bpy
def image(path, colorspace):
img = bpy.data.images.load(path, check_existing=True)
img.colorspace_settings.name = colorspace
return img
def make_pbr_texture_material(name, basecolor, roughness=None, normal_or_bump=None, alpha=False):
mat = bpy.data.materials.new(name)
mat.use_nodes = True
nt = mat.node_tree
bsdf = nt.nodes.get('Principled BSDF')
tex = nt.nodes.new('ShaderNodeTexImage')
tex.image = image(basecolor, 'sRGB')
nt.links.new(tex.outputs['Color'], bsdf.inputs['Base Color'])
if alpha and 'Alpha' in bsdf.inputs:
nt.links.new(tex.outputs['Alpha'], bsdf.inputs['Alpha'])
mat.blend_method = 'BLEND'
if roughness:
r = nt.nodes.new('ShaderNodeTexImage')
r.image = image(roughness, 'Non-Color')
nt.links.new(r.outputs['Color'], bsdf.inputs['Roughness'])
if normal_or_bump:
btex = nt.nodes.new('ShaderNodeTexImage')
btex.image = image(normal_or_bump, 'Non-Color')
bump = nt.nodes.new('ShaderNodeBump')
bump.inputs['Strength'].default_value = 0.02
nt.links.new(btex.outputs['Color'], bump.inputs['Height'])
nt.links.new(bump.outputs['Normal'], bsdf.inputs['Normal'])
return matBake target setup
Blender baking requires a UV map and an active Image Texture node or color attribute as the bake target. Use Cycles for baking.
python
import bpy
obj = bpy.data.objects['GEO-target']
bpy.context.scene.render.engine = 'CYCLES'
img = bpy.data.images.new('BAKE_target', 2048, 2048, alpha=True)
mat = obj.data.materials[0]
mat.use_nodes = True
node = mat.node_tree.nodes.new('ShaderNodeTexImage')
node.image = img
mat.node_tree.nodes.active = node
bpy.context.view_layer.objects.active = obj
obj.select_set(True)
bpy.ops.object.bake(type='DIFFUSE', pass_filter={'COLOR'}, margin=16)
img.filepath_raw = '/tmp/bake_target.png'
img.file_format = 'PNG'
img.save()Closed/extruded surface coverage gate
For closed or extruded assets, do not stop at front projection. Use closed-surface-uv-coverage to verify front cap, back cap, and sidewall material/UV/generated coverage separately. Back/side curve overlays are accents, not texture fill.
Validation checklist
- [ ] UV layer exists and is active.
- [ ] Checker texture shows no obvious stretching on front-facing parts.
- [ ] Atlas rectangles are per-part, not whole-atlas everywhere.
- [ ] Roughness/bump/normal/lightmap color spaces are Non-Color.
- [ ] Alpha material has blend mode set and no black backing plane.
- [ ] Base GLB embeds/exports expected images and excludes reference planes.
- [ ] A front overlay render confirms the texture aligns with the source template.
Sources distilled
- Blender Manual: UV/Image texture workflow requires material nodes for rendered texture output.
- Blender Manual: Image Texture node uses active UV map when Vector is unconnected.
- Blender Manual: Cycles baking requires a UV map and active Image Texture/Color Attribute target.
- Blender Manual: glTF exporter supports meshes, UVs, textures, and materials based mainly on Principled BSDF.
- Khronos glTF PBR: base color, metallic/roughness, normals and related maps are core concepts for realtime transfer.
