Untick Save Alpha because it’s not needed, but keep Save RGB ticked so you can compare the composite against this. Scroll down to where it says Split Render Channels and tick Save Separate Render Channels. Next, in Render Setup go to the V-Ray tab and click to enable the V-Ray Frame Buffer. However, for calculating accurate lighting and materials, you should always use gamma 2.2. Any other gamma value would cause the render elements to be incorrect. This is because when compositing in Photoshop or After Effects the calculations are also done in linear space. Firstly, the render elements must be saved in linear space.

One incorrect setting could cause the composite not to match the intended beauty pass. There are a few settings that need to be set in Render to render out each element correctly. Open 3D World 0164 t_Q&A_164_Max-vray.max from the files accompanying this Q&A. Here, I’ll cover the necessary render elements that make up what’s commonly referred to as the beauty pass. You can tweak the intensity of a reflection, change the diffuse colour and even adjust light intensity. By rendering out each of these elements as a separate image file, you’re able to control every property individually. Each element corresponds to a specific property, such as illumination, shadow, reflection and refraction. The open space renders transparant, the glass space doesnt.A complete rendered image is made up of various individual layers called render elements.

In my testmodel you can see I have simple opening, on the left side there's glass, on the right side it's just open. I've tried the renders with glass as a simple plane as well, but that creates the same issue in saving the background through the window material. I'm using the Vray Window Glass neutral vismat.(I tried others, same problem) The glass has a thickness (otherwise the outside or the reflections get distorted). I have recreated the issue with a simple model. So when you add a background in photoshop it really looks like it's behind a window. The reflections on the window should still be visible in the png, like they used to be before. Thing is, I have to be able to put in a background in Photoshop.

In older Vray versions this was never an issue. Whenever there's a window glass material, vray saves the background through the window instead of transparency. I'm having trouble with rendering PNG images of interior scenes.

Vray photoshop