This feels like it should be so basic, and yet I’m having difficulty. I’m trying to create a glass material where I can see through an object using Principled BSDF. I’ve enabled refraction in the render and material settings, so I see objects behind it just fine.
However, the background for some reason shows the environment map instead of an empty background and I can’t figure out how to make it transparent. I’ve enabled “Transparent” under “Film” in render settings.
I think that the problem also exists in the tutorial, it just happens that this is minimized by the material nodes configuration using Transparent BSDF and Blend Mode in material. NotTransparent_mod.blend (836.3 KB)
Transparency with pure refraction and Film > Transparent does not seem to be possible.
Perhaps you could better discuss this in Devtalk forum.
Edit:
Interesting, the same thing happens in Cycles.
Ok…really simple solution… ( after I spent days working on basic thing myself )
Let me state what you want…Transparent Window - Transparent Background - You want window to Refract Image also?
What you want will not work untill you go into Render View…Not LookDev
I looked at your blend…you already have background transparency On…
If you take and select the window and under settings where you turn on Screen Space Refractions…Under Blend Mode>
1> AlphaBlend with SPR will give you transparent window ( see monkey) but NOT Transparent Window to Background…reflections and SPR makes it seem opaque.
2> Additive will give you Reflections > Transparent ( see monkey) and see Background with NO HDRI
Note: ( this setting is avail in Cycles as well)
Not full RENDER…Screen Render >eevee
You are absolutely right… Have to change my workFlow when I move over to 2.81 completely…
In 2.81…for the same results as above post…You have to include a transparency shader…and Alpha Blend…( this would not work in 2.80 as it would not allow transparency to see the transparency of a second transparent object behind the first…it would make the second vanish where it was behind the first…when using a Trans Shader with a Glossy Shader and did not want to use a Glass shader in Eevee It also caused problems with Hair Strands when Alpha Channel not present. ) At least for Eevee, it does work now!
The same thing just added a transparency shader…with Alpha Blend…
I think it s possible to exclude the background reflection on the world shader. Using light path info in shader editor. Like when you use "is camera ray as a mix factor between environement map and simple background colour. Something like is reflection ray… I don’t remember…
You can find an example of the shader in the world shader of this file
I’m realizing I don’t need refraction to make what I need (thought would’ve been nice). So I’m able to get away with using a mix of Glossy and Transparent BSDFs.
Yeah, that’s weird. I feel like it’s such a basic expectation… I don’t understand why this doesn’t just work. Thanks for trying with the Transparent BSDF!
Could you provide a .blend for your solution? I’m a little lost, haha.
I just realized that for Principled BSDF you don’t need to mix with Transparent BSDF. Just use Alpha slider in Principled BSDF (You still need to configure blend mode)
