Glass object but no alpha??

[steveh27956226]

Hi folks.
Im working on some images which have glass objects on a blank background so the designers can place their own background colour - which will  be a speacific RGB client branding.

I cant seem to render out the glass objects so it has alpha through the glass, it currently seems that what ever colour is in the background get baked solid, meaning the designers cant drop in their colours.

Am i missing something here?
Thanks for your help.

[Ares Hovhannesyan]

I think you need to change translucency values  of that glass.

[AlanGilbertson]

It looks like you have Opacity set to 1. That will "lock in" whatever shows in and on the glass, so that it will be fully opaque in Photoshop.

There are two key properties related to transparency. One is Opacity, in the Base Surface properties (the key word is "Surface"), and the other is Translucency, in the Interior properties. If Translucency is set to 1 (full translucency) and Opacity is also set to 1 (full surface opacity), you will see through the glass material in the viewport, but the environment will be fully reflected from the surface everywhere there is no object, like this. I've rotated the environment light to make it obvious. This is what you get if you use the default Glass material at the top of the Starter Assets, because surface opacity is set to 1.

When this renders out, the glass is opaque. If it showed a background color, that would be opaque. This is quite different from what you would see in real life, so it's counter-intuitive. In my view, it's wrong, but there it is.

With Opacity adjusted to 0.15, this appears in the viewport:

Notice that you can see the background through the glass. It is also transparent in the PSD render.

Opacity and Translucency are a little bit like Opacity and Fill in Photoshop. You can think of it this way: Opacity determines whether you can see [the surface of] the object at all, and Translucency controls whether you can see through it.

In this image, an interior title page for an article in CreativePro Magazine, notice that the tail of the "Y" is visible through the windshield of the car. I added the article title in Photoshop. The glass material in the sport car model uses Translucency and a low Opacity, so I didn't have to do any additional adjustments in Photoshop.

I hope that's useful. Spend some time playing back and forth between these two properties to get a feel for how they interact. It's not intuitive.

[steveh27956226]

Great explianation, thank you very much. It makes sence but doesnt feel right the results dont seem to effect alpha as they would in say VRay it just feels like a transparency level leaving a very unconvincing result. It will suffice for small sections but when the hero image is mostly glass objects it doesnt cut it.
Regards

[AlanGilbertson]

Your experience may be working against you. "It ought to work like X" can get in your way because the right workflow for that environment isn't what you expect. Painter may well be the better tool in this case, although it's hard to tell.

There's also the matter of what an app is intended for. Stager isn't SketchUp or 3DS Max (or Painter, for that matter), and the Mercury engine isn't V-Ray. Those are all very mature products, whereas Stager is still in relatively early stages of development: Version 2.x of anything in the world of software is barely out of kindergarten. Think of Photoshop 2.0, if you can remember that far back, or InDesign 2.0, or SketchUp 2.0.

It doesn't seem like you're part of the Stager prerelease program. You could be a valuable contributor to help test new builds, give direct feedback, and steer development in useful directions. Go to adobeprerelease.com, sign in with your Adobe ID, click on "Available Programs" and look for the Substance 3D Stager Prerelease.

[steveh27956226]

Totally with you Alan, I'm trying to push Stager to realise any limits,  and this helps budgeting when asked to do Stager work. I would love to join the prerelease program as it looks like I'm the go to man in the studio now for Stager/Painter work. Thats not a complaint by the way and looking forward to new features moving forward. I'll sign up now...Regards.

[AlanGilbertson]

Awesome! (I know that "go-to person" gig. I started calling it "Tier Zero tech support." :))

[steveh27956226]

I couldnt see any Stager prerelease app only Sampler. I take it there isnt one yet available?

[AlanGilbertson]

It defintiely exists, because I'm in it, as are several others. Maybe @Cyril Dellenbach or @JMathews can chime in here.