Ability to Adjust Specular Scale for Individual Objects or PBR Materials

Currently there is only one global value for EnvironmentSpecularScale and EnvironmentDiffuseScale; this is all well and good for Roblox experiences made from roblox materials and parts. My issue is the experience I’m working on, Rolling Thunder, uses PBR for EVERYTHING. The only Roblox materials we use are Glass; Forcefield; Neon; and the voxel terrain.

The leads us to some very annoying limitations; I have currently set the EnvironmentSpecularScale to 0.15; and it leads to materials that should be full reflective to looking like wet plastic:

Obviously the solution to this problem is just turning up the specular scale; this is 0.7:

The issue however is that EVERYTHING in the game; even PBR materials that have a full black metalness map; experience this annoying reflective light wrapping effect:

And no matter what settings I change; I can’t get the game to look good above 0.2 Specular scale.

The ability to tweak the specular scale on individual materials or objects would be a life saver; and I consider a much needed feature for PBR only experiences to have a future on the platform.


FWIW this is a feature request that I believe encompasses this one and with greater flexibility.


Thanks for the detailed post. The light wrapping effect comes from fresnel reflections. The light on the hands and gun should be reflecting the ground and trees, but right now, we’re only reflecting the skybox. This can look really wrong when the bottom hemisphere of the skybox is a different color from the ground.

We’ve discussed some ideas to fix the reflections, or at least automatically darken the bottom hemisphere for reflections in the near term. I’m not sure when we will be able to ship a solution. A near term workaround for you could be to choose a skybox with darker lower hemisphere.


Thanks, I will try that. When you say ‘bottom hemisphere’ does that include the bottom half of the left, right, front, and back faces of the skybox? Or just the bottom face?

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Ok so back from trying that:

This is just with the bottom face blackened:

and this is with the bottom face and the bottom half of the sides of the skybox blackened:

As you can see there’s no discernable difference; even when removing the atmosphere effect it still reflects the ENTIRE skybox:

For those wondering; I found a workaround, but it won’t work for every game. Firstly you need the bottom half of your skybox sides to be dark; and you need the bottom face of the skybox to be full black. Then you need to insert an atmosphere effect in lighting and bring the color and decay down REALLY dark. This will impact the atmospheric look of the game, but it’ll fix the light wrap issue. You can also balance the brightness of the atmosphere colors with the specular scale to find a good middle ground between the two extremes.

I went with 0.5 scale and kind of a middle gray on the atmosphere. It gives me some degree of good reflections, but it leaves the atmosphere with this “storm is coming” type of vibe, which works for my game but won’t necessary work thematically for yours: