Hidden actor + Hidden Shadow on translucent material not working?


I have this object that I want to hide, but I want it’s shadow to remain visible. I wanted to use a translucent material on this (to give it a nice soft shadow). I have done the following:

On object: Hidden Shadow and Volumetric translucent shadow (with VMS on or off it still doesn’t work)
Actor hidden in game: True

When I load a non-translucent material on it it works when it’s flagged as hidden in game with hidden shadow on it. Is there a way to get this to work, or can this feature be added to UE4? We need this for window shading/screens to be rendered nicely in-game. Or is there another way to do this?


  • Wesley

Sorry to resurrect this, but it’s the top relevant link that came up when I was googling the exact same issue. When the translucent object is visible, it casts translucent shadows just fine, and if I swap the material to be opaque, it casts hidden shadows fine as well, but translucent shadows + hidden in game fails to create any shadows.

I’m not sure if translucent shadows being unable to work with the ‘cast hidden shadows’ and ‘hidden in game’ features enabled is a fixable bug or a rendering limitation that can’t be rectified.

I’m not on my computer but there are 2 settings you can try as I remember: Cast hidden shadow and cast shadow as being opaque. I can try to find this tomorrow. Btw if it is hidden in game, why does it need to be translucent? Can’t it be opaque and hidden?

Ohh this is an old problem, I think it was a bug in the newer version. So basically the “Hidden Shadow” in a Static Mesh doesn’t work with translucent materials so far.

I think it has something to do with which buffer translucency is applied to, and how it has to correspond or be rendered in the correct order along with a hidden shadow. Like taking the hidden shadow out of one buffer and placing it in another. If it’s still there in the learning portal, there’s a page describing the G-buffer and D-buffer that makes reference to certain limitations of the engine because of how it is set by default in the pipeline, and potentially revealing how it can be changed to get different effects to render that otherwise aren’t or are limited.