How to bake metal/smoothness map for Unity?

[trojanfoe]

Hi there, I would like to bake all the textures of my game assets for use in Unity where the smoothness is baked into the metal map alpha channel.  I cannot see from the Bake Textures ROP node how to do this?  Do I need to create/use a non-standard shader for this?

Here is the test geo from Houdini (note rough blue material):

 

and this is what it looks like in Unity (note shiny blue material):

 

Here is the project.  I am using Houdini Indie 16.0.578 under Windows 10.

 

 

Edited April 29, 2017 by trojanfoe

[trojanfoe]

OK, I think I've solved it by hacking the Principle shader.

Edited April 29, 2017 by trojanfoe