Blender material management skill.
For existing material metallic/roughness edits, load blender-shader-nodes
and use set_principled_inputs with material_name and
inputs: {"Metallic": 0.94, "Roughness": 0.28}. Use list_node_sockets to inspect
the target node and its linked sockets first; a linked socket's default value
does not replace its upstream shader. Material creation already accepts PBR
values; do not recreate an existing material just to change its roughness.
MaterialX round-trip
export_materialx writes Principled BSDF socket values to a .mtlx document as
a standard_surface shader, and import_materialx reads standard_surface,
open_pbr_surface and usd_preview_surface documents back into Principled BSDF
materials. Both directions carry values only: a socket driven by an upstream node
is reported under linked_inputs / connected_inputs and keeps its default
value, so textures and node graphs are never silently baked or dropped.