Hi all. So, my question is why some nodes of my grid graph are unwalkable( undergrounded) and how i can fix it, with different way than set lower node size?!
Hi
Those nodes that looks like they are underground are not unwalkable, they merely look like that because the gizmo drawing happens to draw the lines below the ground, so they show up darker. Unwalkable nodes are nodes which show up as red cubes (I think I can see some in the background in the screenshot).
Ye, you’r right, but sometimes my units get stuck on the ground, and it seem’s like they path goes underground, and they looks like 
Try to not be that dependent on path Y-axis data since it is usually of quite low resolution. Instead you could for example fire a raycast downwards and use that information to place your units at a constant 0.5 meters or something above the ground. That will also give you more aesthetically pleasing results.
Hmm… okay, i will try that way. Thanks a lot for you help!