Rect Light not reflecting on glass

Hello peeps.
I’m putting together an animation I did a few years ago (with Octane) in UE 4.25.3.
Using the new Automotive Materials and it’s all going super well.

My roadblock occurred when I started lighting the car properly, the windows wouldn’t reflect Rect Lights.
They would light the metal and plastic but not the glass at all.

I’m using all the RayTracing options, but nothing.
In the pictures attached you can see I’ve got a HDRI and a spot light with a bit of Source Radius reflecting all good, but not the Rect light.
Also to note is that I’ve got a HDR image as a Source Texture.

Thanks in advance troops.

hi there .
i think you need to change the lighting mode of you glass material.


Thanks Expose for replying.
The material settings are the same for me as well I’m afraid :frowning:

Hi Expose
Thanks for replying.
The materials I’m using are from Epic’s Automotive Materials and within that set is a Glass RT. Looks great with a HDRI and with the spot and point lights… just not with the Rect light.

I must be missing something, I can’t believe it is this hard to get a reflection out of a light.


P.S. I’d love for Epic to make a multi GPU non game production version, where as you are making something for spitting it out to a GPU or two. I’ve got four GPU’s and it’s just a pity it only uses one.

Well I gave up in frustration today a in a fit I deleted my Audi folder.
After a cup of tea and regretting the decision I started a fresh and loaded it all back together of another try…
And now it works! I did nothing different, but apparently I must have.

This is the screengrab…

Very baffled, almost scared to shut the PC down in case the gremlins get to it.

hi there !
i forgot something :slight_smile: the rect light as a parameter called specular scale, whent turned to 0 it makes the rect light disappearing from reflections

Hey Expose
Yeah I’m aware of that option.
Funny thing is, I created a new scene from scratch, imported all goe and mats again, and for some reason the reflections are now present. So it all works like it should but I have no idea why it did that and not originally!!!