Mirrors and Dirt shader issue

[Rrock]

Im trying to make tiled infinite landscapes with mirrors. On landscape material i used dirt shader for 'snow' effect.
When i placed planes with mirror material (index 1), i got this weird lines. This lines produced by dirt shader.

Lines:


Scene:



Material:

[renderingz]

the dirtmap result will be affected by objects close to or intersecting the object with the dirtmap applied.

potential solutions;

1) try adding an octane object tag to the mirror and turning off shadow visibility

2) separate the mountains from the ground, and apply material without dirt to the ground plane

3) Use the map driving the landscape displacement to mix between a material with and without the dirtmap.