How to Recieve and cast shadows with Translucent Material

​Hello,

I am strugling to create a curtain material. Basically I need something like this:

I am using ray traced shadows, and I am aware that translucent objects do not cast shadows in ray trace…but as this image show, there should be shadows working with lightmaps…so my plan was to calculate the lightmaps and turn off in the material the “cast raytraced shadows” so the dim light would appear from the lightmaps.

I have two problems, as you can see in the next image, I can not get the material to dim the light, even with ray traced shadows off in the directional light…the material is set as:

Blend Mode: Translucent

Shading mode: Default Lit (also tryed subsurface, no luck)

two sided: true

cast ray traced shadoes: false

Translucency Lightning mode: Surface forwardshading (I use this because I want my object to recieve shadows, also tryed the Surface Translucency Volume with no luck, see post refence down here)

In the object details:

Cast Shadows: True

Volumetric translucent Shadow: true

In the directional light: Cast Translucent Shadows: True

as you can see, no dim light

The second problem, is that I use the “Surface forwardshading” translucency mode in the material, in order to get shadows from other objects castet in my object with this translucent material applied. As you can see in the next image, the quality of this shadows is not good:

As I already sayd also tryed this from another post, but not working for me, even using a geometry with thickness:

https://answers.unrealengine.com/que...ml?sort=oldest

Assuming that you have multiple materials setup for your mesh and the window material is it’s own material you will need to set the following things.

Material: Blend Mode: Translucent Two-Sided: True Lighting Mode: Surface Translucency Volume

Then for your mesh placed in the level select it. In it’s Details Panel make sure that Volumetric Translucent Shadow is set to True.

This will cast a shadow from a translucent material, however the more opaque the material the more you’ll notice artifacts on the mesh itself.

Here is an example with a simple cube mesh and basic translucent material.

You may also notice that there is transmission of light (ie. color of the translucent object does not cast to the ground). This is not implemented currently and can only be done by using only static lighting

So my questions are:

1 - How can I do a simple translucency material that dims the light that goes trough the object?

2 - How can I make that my translucence object recieve shadows?

Thank you very much!​

In the second photo of the overhang outside with a glass roof, what is the base color value in the glass material? That affects how dark or light the shadow displays on the surface its cast on. Something could be changed to brighten the glass material after that, if it’s too dark how it appears when viewed directly.