How to render an image in which pixel stores the index on the corresponding face?

We can render barycentric coordinates image in Parametric (Shader Editor >> Geometry node), but how to access the corresponding face index?

Is it related to ptex_face_id in Attribute?

How to render an image in which pixel stores the index on the corresponding face?

We can render barycentric coordinates image in Parametric (Shader Editor >> Geometry node), but how to access the corresponding face index?

Is it related to ptex_face_id in Attribute?

And there's Object Index, Material Index, but no Face Index in Indexes.

How to render an image in which pixel stores the index on the corresponding face? Is it related to ptex_face_id in Attribute?

How to render an image in which pixel stores the index on the corresponding face?

We can render barycentric coordinates image in Parametric (Shader Editor >> Geometry node), but how to access the corresponding face index?

Is it related to ptex_face_id in Attribute?