Glass has extreme sun reflections at transparency 0.999

Reproduction Steps
I have noticed that the glass material with any transparency will show a massive sun as the reflection which is really annoying as it ruins the ability to create cool effects which you can only do with glass material at some times.



You can see that the entire part exists because of the reflection and when you look the opposite direction, you cant even see the part at all.

If there was some way we could disable this material reflection ourselves or scale the reflection effect ourselves without having to decrease the brightness in the lighting, it would help so much.

I still want the rest to look correctly, but the glass has just too much reflection.

Repro steps:

  1. Create a baseplate place with brightness set to 3 in the lighting.
  2. Create a part with glass material and set the transparency to 0.999.
  3. Look for the reflection of the sun.

Expected Behavior
The reflection to become less dependend on the transparency of the part or the reflection to be completely disabled.

Actual Behavior
A massive sun appears on an almost invisible part.

Issue Area: Engine
Issue Type: Display
Impact: High
Frequency: Constantly

10 Likes

Thanks for the report! We’ve filed a ticket to our internal database and we’ll follow up when we have an update for you.

5 Likes

It’s intentional behavior of glass. If transparency is high, you can use other materials to hide specular.

That did not work, i have tried overlapping the fabric material ontop of it, but it still showed the insane sun reflection.
In order to get rid of it i have to stretch a skinned meshpart all the way down at the area where the sun would have reflected off of the surface, this is really bad performance wise and a total pain to do so.

I cant use texture appearance aswell to get rid of it because that would get rid of the glass rendering effect.

Im not talking about the specular effect im talking about the sun itself which is still visible when specular is set to 0.
The sun reflection is also still visible whenever there are clouds covering the entire sky.



1 Like

I mean get rid of glass… What glass rendering effect do you want? The strong specular is part of Glass’s special rendering effect.

I use glass to get rid of certain textures / decals or weird effects and by applying surface appearance, it gets rid of the sun reflection but at the same time it disables the rendering mechanic i use a lot.

This causes me to be unable to get rid of a massive sun reflection on my brand new ocean for an example.

for anyone still looking for a fix:
turn brightness to 0 in lighting and adjust ambient to match the previous look. After that you can use a SunRays instance and change its properties to make a false sun that doesn’t have reflections. (You can also set glass transparency higher than 1 for a stronger visual)

glass’s special effect should definitely be added as a shader along with a few other simple ones. It’s impressive how much roblox devs can do in hacky ways with just glass.

1 Like

There should be some extra effort put into these limitations on glass, they make them a pain to use. The exaggerated effect is unnecessary and unrealistic. Glass at transparency 1 or near 1 should have a “ShowCelestialBodies” bool property which would compromise existing engine behavior and more realistic behavior.