For CAD objects I don’t want to make it mirror material in the layout editor as only some part of it is reflector surface most of time.

So if I choose “Reflective” in the “Face Is” line under Coat/Scatter property of object, is that working like thick Aluminum surface? 

What if I want to apply certain reflectivity values different from Aluminum on that surface. Should I leave the face as Reflective and choose one of I.xx coatings in the list?

@jsung

At the bottom right of an Object Properties, you’ll find a blue exclamation mark icon, which generally brings you to the relevant part of the Help File.

If you read the section Face Is you’ll find the following.

If you want a specific reflectivity, use a coating. The Coating takes precedence over Face Is Reflective.

You can make a dummy system, such as a Source Ray (1W) reflected on the face of a Rectangular Volume and onto a Detector.

If you use Face Is Reflective and no Coating you get (with Use Polarization in the ray trace):

If you use Face Is Reflective and Coating I.0 you get (with Use Polarization in the ray trace):

Note that you can also have a Coating with Face Is Object Default, and if the Rectangular Volume doesn’t have a material (as in my example), or is made of a refractive material, you would have transmitted rays go through the Rectangular Volume (here I used I.50):

I hope this helps and take care,

David

Thanks Daivd for answers to both of my questions yesterday.

Yes, I looked at the F1 help on the bottom right on this and understand how “Reflective” face would work from coating properties. Wasn’t just sure how that would work when combined with coating file.

So if coating like I.50 is applied on reflective face of transparent material we would have both reflective and transmitted rays? I would test it myself, but just got curious.

@jsung 

No you wouldn’t, the moment you have Face Is Reflective, this part of the Help File applies:

As you can see at the bottom of my post. You need to have Face Is Object Default and a transparent material to get transmitted rays.

Let me know if this isn’t clear.

David

Thanks. Seems I missed that phrase in the help. that makes sense.

What if I want to have specific reflectivity instead of just thick aluminum. Can I apply some coating with specific R values on that reflective face or should that face be object default for such coating? In other words reflective face makes just thick aluminum surface regardless of coating file?

@jsung 

It seems I wasn’t clear with my first reply.

If you have Face Is Reflective AND a coating, such a I.50. Then, it is the coating that is considered and not the thick aluminum.

Let me know if this is clear.

Take care,

David

Yes, all is clear now. I missed some of your phrases in the original reply. Also I did my own test in the Zemax NSC mode. Thanks.