For future readers:
The triplanar node is mostly to make your normals as correct as possible with one normal map, regardless of the mesh’s face normals.
I tried to use a triplanar set up , (no triplanar node, but the correct way, found here:. Shadergraph triplanar object space normal mapping help ) , but mixing a “grass layer” for y-plane, with the “rock” for mountain sides, but this created ugly horizontal lines, that looked kind of like some mountains do, but not the result i wanted. Changing blend power then just made the grass layer look like a scotch / criss cross pattern.
Then i figured out what the triplanar node is really for, (second phrase of this post), and used that only for rock, all three sides. My mountains looked awesome, but i had no “grass”. (In my case, a strategic map, i made a forest canopy texture). I then basically created a mask in the shader, where the steeper the vertex normal, the more rock, and less “grass” showed. Mixed it up, and my new terrain shader, using the triplanar node, was incredibly faster, 12 percent in fps overall.
I did not use triplanar node for the grass part, as well as rock, though i tested it, and it only; slowed my fps by about 3percent compared to the triplanar rock + masked grass. However, the artistic effect on the grass/canopy was negligible, so i opted to save the three percent fps.
Tl:dr the triplanar node is much faster than the old and not-so-correct way seen in most older tutorials. Furthermore, it looks way better. I now have the best of both worlds, smear free, detailed mountains and hills that react to light correctly, and in the flatter areas, a nice looking forest canopy.