blender-materials-shaders

Blender Materials & Shaders Skill

Version: 2.1.2 Last Updated: 2026-10-09 Dependencies: Blender 5.1+

Breaking Changes (4.5+ / 5.1+)

import bpy

# Render engine (5.1+)
bpy.context.scene.render.engine = 'BLENDER_EEVEE_NEXT'  # Not 'BLENDER_EEVEE'

# Principled BSDF input names changed in 4.5.0 - use names not indices
bsdf.inputs['Transmission Weight'].default_value = 1.0  # was 'Transmission'
bsdf.inputs['Subsurface Weight'].default_value = 0.2    # was 'Subsurface'
bsdf.inputs['Emission Color'].default_value = (1,1,1,1) # was 'Emission'
bsdf.inputs['Base Color'].default_value = (0.8, 0.2, 0.2, 1.0)

Procedural texturing on parametric geometry (loop-gauntlet lessons, 2026-09-10)

• Use Texture Coordinate > Object, not the default Generated coordinates, for procedural textures on parametric architecture. A Noise texture on Generated coordinates stretched into streaks on 120-segment arc rings and long boxes; Object coordinates are metric and isotropic because all objects share the world origin.
• Caveat: Object coordinates are relative to the object, so changing the object's transform changes the material. Applying transforms, joining, realising instances, baking to world space or re-centring the origin silently changes the scale, orientation or phase of every pattern fed by Texture Coordinate > Object - no error, and the geometry numbers (face count, bounding box, part count) still pass. Two relatives: a procedural node with an unlinked Vector input uses Generated coordinates (the mesh bounding box), and Geometry > Position is world space. Before applying or baking, list the materials that read any of these (check inside node groups too). Either keep the transform, or store the evaluated object-space coordinates as a FLOAT_VECTOR point attribute BEFORE the bake and replace every linked Object output with the Vector output of an Attribute node (type Geometry, that attribute name). Read-back: render the same camera rig from the source and from the result and compare the images, or sample one pixel - a mean absolute difference of 1.1e-3 against 1.5e-4 once fixed was invisible by eye at 512 px and was the only signal.
• Brick texture reads the X/Y of its input vector - it is planar in that plane, not aligned to the surface it is applied to. On a wall lying in the YZ plane a Brick texture produces blotches instead of coursing. Build a Z-based course mask instead (SeparateXYZ > multiply > fract > less-than > bump) - it works on every wall orientation and lines up scene-wide.
• A texture that shares a shader with an already-accepted plate must share its histogram. Before assigning a new image plate to a shader slot that an accepted plate already uses, match the new plate's luminance mean and standard deviation to the accepted one (a two-line PIL script: read both images, scale/offset the new one to match mean and std). Two extra relief plates with greyscale means of 126 and 172 against an accepted plate's 181 rendered as dark grey stone instead of matching stone, costing a full iteration before the mismatch was found.
• A photo's surface grain becomes an unwanted bump map at close range. A photo-derived plate used as colour-plus-bump reads as rough bark texture when the nearest matched camera is close (about 2 m); reserve photo-derived plates for bands whose nearest camera is several metres away, and use the smoothest (e.g. generated) plate on close-up bands.