The default M_Glass in the starter content is doing things with refraction it shouldn’t:
This is not how glass works. Anyone know how to fix this and is this a bug?
This is not how glass works. Anyone know how to fix this and is this a bug?
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It’s refraction, you’re just looking into the glass at an acute angle.
If you want to stop it happening, you can reduce the refraction here
1 = No refraction.
But then it won’t look like glass 
Yea I get that, but why is it refracted like that, because last time I checked I couldn’t see somewhere the glass couldn’t see through the glass.
Since refraction bends light rays, actually yes you can see somewhere different when looking through glass compared to if it wasn’t present - just like how you can see around a corner with a mirror, due to the changing direction of light rays as they bounce.
But the reason this is happening in a way that looks unnatural is because you’re probably using screen space refraction (as opposed to ray traced refraction). Screen space refraction is an approximation, and generally shouldn’t be used on large surfaces due to it’s limitations.
Actually, I am not using screen space refraction.
Unless you’ve explicitly toggled refraction to raytracing in your prost process volume, yes you are using screenspace.
Default (screen space) showing artifacts:
Ray Traced:
Inside the PPV:
Also note the method of refraction used inside the material:
Personally I would just either turn refraction off, or tone down the IOR significantly. RT refraction is overkill most of the time.
And I just tested, even when setting it like that in the ppv it doesn’t work.
Your project needs to have hardware raytracing enabled, with a RT capable GPU.
Check your project settings. Regardless, refraction is the cause. Non-RT refraction has significant limitations just like all screen space techniques so “doing things it shouldn’t” is expected.
Avoid using it on large surfaces. Don’t use it on windows. Screen space refraction should be limited to small, curved surfaces like glass bottles, where the curvature can show off the effect but the size is limited enough that artifacts wont be noticeable.
With RT refraction, you’ll want to set the material to two sided as well. Without this, the ray will only bend once when entering the medium, but not a second time as it exits. Bear in mind, RT is not without it’s limitations as well though, such as a finite tracing distance.
Yea I’m probably gonna turn it off again.