JoeW97
1
If you visualise a terrain heightmap as a grid of quads, the quads are triangulated along +x & +z.
e.g. the quad (0,0) (0,1) (1,1) (0,1) is cut between (0,0) and (1,1) [See below]
This means that if you set heights on a diagonal line of points with direction (1,1), you get a perfect line.
But if your line has direction (-1,1) or (1,-1) then you get a broken line of individual spikes, because the triangles fold between each point.
This isn’t a problem when there is thickness/width to the area, but even then the edges will be jagged.
I know this problem isn’t often seen because most ways of modifying the terrain will involve some smoothing/anti-aliasing, but when you’re trying to be precise it’s very obvious.
Is there any way to reduce this problem? Can the heightmap be made to tessellate in both directions?
Or will it just be a case of anti-aliasing the edges with a line algorithm?
You’re trying to use a terrain in a way it was not designed for (it’s usually used for larger details, as you said yourself). You can not change quad split direction. You will also loose your details once LOD kicks in.
Maybe you should just generate mesh instead?
