source/blender/gpu/shaders/material/gpu_shader_material_principled.glsl

@@ -55,6 +55,8 @@ void node_bsdf_principled(vec4 base_color,
                           vec4 sheen_tint,
                           vec4 emission,
                           float emission_strength,
+                          float thin_film_thickness,
+                          float thin_film_ior,
                           const float do_diffuse,
                           const float do_coat,
                           const float do_refraction,