Lumen glass materials archviz

[Idgi]

Hello,

is it expected result that when using translucent materials and Ray traced shadows in the directional light, light goes not through the object?

Simple Glass Material:

this would be the expected result:

[alberto]

Hello @Idgi not sure what is happening but for sure you can’t use this kind of value for material like 0 and 1, will not work for sure

[Idgi]

Hello @alberto , those values are already corrected on the Material instance:

[alberto]

@Idgi

light goes not through the object

What do you mean?

[alberto]

By the way I just found this, I’m reading it

Lumen GI and Reflections feedback thread

Thank you!

[Idgi]

when using raytraced shadows in the directional light, happens this:

it should be like this:

[alberto]

ahhhh wait a bit

[alberto]

I think the problem is in the material, I did create a new level, not even post process, here you have my settings:

The glass I’m using is in the free content:

[alberto]

Using a postprocess I did add even refraction and looks well

[Idgi]

I am downloading the Materials!
do you have “Cast Ray Traced Shadows” enabled in your directional Light?

[alberto]

sure yes

[Idgi]

checked the materials of the pack, they work because they have “Cast raytraced shadows” uncheck in the material…so I guess, raytraced shadows and translucency do not work together, wich was my question from the begining…thank you @alberto

[alberto]

wait wait, what you want is a directional light that is casting raytracing shadows

I don’t see window glasses making shadows… occlusion yes but no shadows!

I mean when I’m inside a car the shadows are projected from directional light, in any case the glass is projecting shadows

[alberto]

"A transparent object will not create any shadow, as the light will pass straight through the object, but such transparent objects do not allow all the light to pass through them, they still interact with light through refraction. "

this is how it works:

Does Glass Have A Shadow? - QuestionAnswer.io

[Idgi]

well, if you have a pure transparent object, it will not form shadow, but that does not exist in real live, the same way there are no pure black and white objects…just put a any object made of glass under a light…for flat surfaces you do not notice that much because is “everywhere”

unreal version of this

But anyway, my goal with my question was to know if raytraced shadows and translucency was working together, and the answer seems to be no, thank you for pointing me to the material library!

[alberto]

No shadows is just refracting occluding light… but well Is late for me

[Idgi]

@alberto again thank you for your help!!

[alberto]

You are welcome, the only thing I can add is this:

The Awesome 4.27/UE5 Update Nobody Is Talking About

[Idgi]

that does not happen anymore in UE5 sadly

[mm-3d]

Hi everyone.
The solution is explained in this video by Jason Gautier:

Fixing your Glass in Unreal Engine 5