Foliage disappears when moving camera

Hello everyone,

My foliage, like grass, disappears when i move the camera from left to right, depending on the angle.

Someone have a solution please ?

Thank you and have a nice day !

In fact, in find the problem,

for those who have this problem, type the command:
Foliage.MaxTrianglesToRender

With a long number at the end of the command, your foliage can’t disappear.