Weird triangles on MagicaVoxel model

Hi guys!
Here's my problem. I have created a model in MagicalVoxel, exported as .obj file and imported into unity.
But there are two problems: the first is that I see some weird triangles shadows on the side of my pig (bad interaction between directional light and normals?), and the second is the shadow on the floor that has holes (actually I "solved" this problem setting "Cast Shadows" on Mesh Renderer component to "Two sided", what does it mean?).

Do you have any ideas on how to solve my problems?

Thanks

 

And nobody helps me...

 

For anyone having this problem: this is simply because you have set shadow cascades to 0. Meaning there are shadows generated only for a certain distance from the camera. When you get up close you still see the same shadows, just magnified. To fix this you need to set cascades to at least 2.