Some information on Terrain Collision wanted.

[DaveHoskins]

Hi, I’m making my own terrain data and I want to apply collision data to it.
I have it sort of working, but I need some more info. Can anyone help?

I realised that the height data needs to be in the 0-1 range and the scale is the ‘size’ Vector3.

But I don’t know the orientation of the terrain or the order the terrain vertices are in, or whether the position is the centre of the terrain or a corner?
I don’t know if needs rotating, but I have tried every angle there is, and it’s seems to be off by quite a bit.
My patches are 65x65 is size.

What I really want is a way of Rendering the Terrain Collision triangles.

Thanks,
Dave H.

For each patch I do…

coll = GetComponent<TerrainCollider>();
coll.terrainData = new TerrainData();
coll.transform.position = transform.position;     // Is this the centre or an edge?
coll.terrainData.heightmapResolution = widthGrid;   // 65x65 
coll.terrainData.size = new Vector3(patchWidth, 80.0f, patchWidth);
heights = coll.terrainData.GetHeights(0, 0, (int)widthGrid, (int)widthGrid);

// Later...

int i = 0;
for (int z = 0; z < widthGrid; z++)
{
	for (int x = 0; x < widthGrid; x++)
	{
		float h = vertices[i].y / 80.0f;
		h = Mathf.Clamp(h, 0.0f, 1.0f);
		heights[x, z] = h;
		i++;
	}
}
coll.transform.position = transform.position;
coll.terrainData.SetHeights(0, 0, heights);
coll.terrainData.physicMaterial = null;

[Eric5h5]

Not quite sure what you’re asking. The terrain collider is a special heightmap collider in PhysX; you don’t compute vertices or anything. When you use SetHeights, the terrain/heightmap collider is updated with the new heights.

–Eric

[DaveHoskins]

I’m not using the built in Terrain objects. I’m creating my own fractal terrain, that has thousands of miles worth of patches.
I have game-objects rolling around on it with a TerrainCollider, but they are not in the correct place. I think I’ve discovered that the terrain starts at the ‘transform.position’ minimum corner, rather than that being the centre. But there doesn’t seem to be much info on anything else.

[DaveHoskins]

OK, I have it working now. I had to swap the X and Z coordinates around and put the ‘transform.position’ at the lower left X Z position of each rendered mesh