default translucency for PBR authoring tools generally assume premul, not lerpalpha nowadays

Engine/source/materials/materialDefinition.cpp

@@ -207,7 +207,7 @@ Material::Material()
    mDoubleSided = false;
 
    mTranslucent = false;
-   mTranslucentBlendOp = LerpAlpha;
+   mTranslucentBlendOp = PreMul;
    mTranslucentZWrite = false;
 
    mAlphaTest = false;