It seems that the specularityFactor property in a StandardMaterial incorrectly affects diffuse, when useMetalnessSpecularColor = true. This issue is most apparent when loading a glTF that relies on the KHR_materials_specular extension. If the glTF has "specularFactor": 0, the diffuse color is ignored in the engine, which it shouldn't.
See the attached Sphere.glb viewed in the official glTF viewer (expected result) compared to PlayCanvas glTF viewer (actual result):
This issue exists in both the latest 2.x and 1.x versions of the PlayCanvas engine.
It seems that the
specularityFactorproperty in aStandardMaterialincorrectly affects diffuse, whenuseMetalnessSpecularColor = true. This issue is most apparent when loading a glTF that relies on theKHR_materials_specularextension. If the glTF has"specularFactor": 0, the diffuse color is ignored in the engine, which it shouldn't.See the attached Sphere.glb viewed in the official glTF viewer (expected result) compared to PlayCanvas glTF viewer (actual result):
This issue exists in both the latest 2.x and 1.x versions of the PlayCanvas engine.