Sun not reflected on material

Hi folks,

for some reason I can’t get any specular reflections on my translucent material. You might think there is something wrong with the material parameters, nodes etc. but the material preview shows the material exactly how it is supposed to be. In editor though, the result is very similar, just without any specularity. Let’s take a look at some screenshots:

Here we see the roughness map showing some dirty, greasy spots on the material in opaque mode (preview and on object)

Same material, same settings, same sun settings, same everything. I just changed the material blend mode from “opaque” to “translucent”.

In the material preview you can still see the greasy spots reflecting in a diffuse fashion on a transparent material. Just like it should be.

On the actual object though, you see no reflection of the sun. You can see reflection of the objects (I used a planar reflection) but not the sun, and therefore no greasy spots. The lighting mode is set to “Surface TranslucencyVolume” like it should be for glass materials.

I tried increasing/decreasing the specularity/roughness/opacity/metallic through a constant to no avail. I can’t really wrap my head around why the preview is correct and the actual look on an object isn’t (I used the same mesh for material preview). I hope you can clarify what’s going on. Thanks.

Are you using static lighting? The preview light is dynamic.

EDIT: Also, do you have a skylight and reflection capture?

I indeed use static lighting, though for the sake of this question I also enabled a movable directional light (the one you see reflected in the first picture). For the skylight I use the HDRI Backdrop with a custom hdri which works fine for all other surfaces and materials. I had no reflection capture until now, though that did not alleviate this problem.

Darn… :-/