Translucent materials do not render if no light is hitting the surface directly.

Hi.

I just wanted to make Epic aware of this problem. Maybe its not a problem but just the way the rendering engine is supposed to work.

In short. Translucent materials do not get drawn if light is not cast on the surface. So areas in shadows are invisible.
As a workaround i added emissiveness to the material.

https://forums.unrealengine.com/showthread.php?61873-No-static-Lighting-on-Dynamic-objects-on-Mobile-Workaround-and-Translucency

Hi Crocopede,

Please post this to the answerhub in the bug reports section at http://answers.unrealengine.com so we can assist you in depth. Thank you.

Will do. Thank you