Seams appearing in Terrain after deformation

Troubleshooting terramonkey
1

Hello guys,

I am working on an evolution project that deforms the terrain each generation and tries to adapt it to a creature. For example I’m trying to move a sphere through random mutation of the terrain to a certain spot. After a few mutations seams between patches appear as in this screenshot:

The basic rundown of the program is:
Attach the individual, evaluate the fitness, detach everything(terrain and creature) and then attach the next individual.

After all individuals are done I select a few individuals(clone them) and mutate them with the following code which is from TerrainTestModifyHeight with a bit of randomness.

[java]
public static TerrainQuad mutateTerrain(TerrainQuad terrain, int max, float strength) {
float p = FastMath.nextRandomFloat();
if (p > strength) {
float locx = (FastMath.nextRandomFloat() * 64 * 2) - 64f;
float locz = (FastMath.nextRandomFloat() * 64 * 2) - 64f;
float radius = FastMath.nextRandomFloat() * 32 + 8;
float str = FastMath.nextRandomFloat() * (4.5f * 2) - 4.5f;
adjustHeight(new Vector3f(locx, 0, locz), radius, str, terrain);
}
return terrain;
}

private static void adjustHeight(Vector3f loc, float radius, float height, TerrainQuad terrain) {
    // offset it by radius because in the loop we iterate through 2 radii
    int radiusStepsX = (int) (radius / terrain.getLocalScale().x);
    int radiusStepsZ = (int) (radius / terrain.getLocalScale().z);

    float xStepAmount = terrain.getLocalScale().x;
    float zStepAmount = terrain.getLocalScale().z;
    List<Vector2f> locs = new ArrayList<>();
    List<Float> heights = new ArrayList<>();

    for (int z = -radiusStepsZ; z < radiusStepsZ; z++) {
        for (int x = -radiusStepsX; x < radiusStepsX; x++) {

            float locX = loc.x + (x * xStepAmount);
            float locZ = loc.z + (z * zStepAmount);

            if (isInRadius(locX - loc.x, locZ - loc.z, radius)) {
                // see if it is in the radius of the tool
                float h = calculateHeight(radius, height, locX - loc.x, locZ - loc.z);
                locs.add(new Vector2f(locX, locZ));
                heights.add(h);
            }
        }
    }
    terrain.adjustHeight(locs, heights);

    terrain.updateModelBound();
}[/java]

I’m wondering if I can somehow avoid those seams or maybe there is a good way to fix them after(smooth step after mutation). I have not noticed this behaviour when the terrain is attached. So maybe the cloning process causes issues? For that purpose I use deepClone on the terrain to replicate the terrain for a new cloned individual.

I hope this description helps. If not let me know and I’ll try to provide some kind of test case. Any help is appreciated!

2

make sure the borders are the same height, i think that the terrain requires this.

3

After a lot of smoothing attempts and trying to fix the seams on my own I actually found the error somewhere else in my code.
While I’m trying to clone individuals I used this code.
[java]
TerrainQuad newTerrain = (TerrainQuad)terrain.deepClone();
[/java]
But I should’ve used:
[java]
TerrainQuad newTerrain = new TerrainQuad(“my terrain”, 65, terrain.getTerrainSize(), terrain.getHeightMap().clone());
[/java]
This fixed the seams from appearing. I have really no clue why this is the case but they don’t appear anymore. I’m really not happy with that knowledge though :-x …