EEVEEでDiffuse RayとGlossy Rayを区別できない
5.0で直りました
https://projects.blender.org/blender/blender/commit/8bde4854bdaa18375df3439a8800167bcddbb5d7
4.2のBug
4.3のBug
4.4のBug
4.5のBug
EEVEEはLight Path Nodeを使用してis Diffuse Rayにのみ別の処理をするということができない
https://gyazo.com/16480a3a3714737cd0f5c12388f40266
代わりにis Glossy Rayを使えばできる
が、それだとDiffuse BSDFとRefraction BSDFとで処理を分けれない
EEVEE Legacyはできる
https://gyazo.com/0f37bf7c3ef39b731666056a51093da4
当然Cyclesもできる
#123299 - EEVEE Next : Light Path node Is Glossy Ray cannot distinguish between diffuse material and glossy material. - blender - Blender Projects
Miguel Pozo
This is a known limitation.
The Light Path node is only partially supported in EEVEE.
Is Glossy Ray is always true for Plane and Sphere probes (including the World probe).
Is Diffuse Ray is always true for Volume probes.
Is Shadow Ray is always true for shadow maps.
Otherwise, Is Camera Ray is true.
ちなみにマニュアルには書かれていない（？）
https://docs.blender.org/manual/en/4.4/render/shader_nodes/input/light_path.html#eevee-support