Vulkan shadow problem in landscape

[rawjuniperberry1]

Hi, I’m creating mobile game, with forward shading and I have a problem with shadows on the landscape in vulkan like in screenshot:

I use GPU Lightmass plugin to build light, and I find landscape material to get low poly effect, which looks like this:

I don’t know why it looks so bad, have you any idea?

[rawjuniperberry1]

I find a solution, this is weird because I know about this option and somehow I didn’t check it before.

In material details under the mobile category, I check Use Full Precision and that fixed my problem