How can I make masked material assets keep showing?

Hi there,

I have a problem of visibility. I used foliage to put grass assets on the landscape and also rocks too.
These seems to work at the first but when moving the camera back, literally only grasses was disappearing.
Both were set by foliage though. I guess it’s because Masked material is assigned.
But I want to keep them showing even though camera go far away from objects.
How can I fix that??