public static Brush CreateBrush(ErosionParametersComponent erosionParameters, int mapSize)
{
var erosionBrushRadius = erosionParameters.ErosionBrushRadius;
var erosionBrushRadiusSquare = erosionBrushRadius * erosionBrushRadius;
var brushIndexOffsets = new List <int>();
var brushWeights = new List <float>();
var weightSum = 0f;
for (var brushY = -erosionBrushRadius; brushY <= erosionBrushRadius; brushY++)
{
for (var brushX = -erosionBrushRadius; brushX <= erosionBrushRadius; brushX++)
{
var sqrDst = brushX * brushX + brushY * brushY;
if (sqrDst < erosionBrushRadiusSquare)
{
brushIndexOffsets.Add(brushY * mapSize + brushX);
var brushWeight = 1 - Mathf.Sqrt(sqrDst) / erosionBrushRadius;
weightSum += brushWeight;
brushWeights.Add(brushWeight);
}
}
}
return(new Brush()
{
Weights = brushWeights.Select(weight => weight / weightSum).ToList(),
IndexOffsets = brushIndexOffsets
});
}
private void ConstructMesh(
MapInfoComponent mapInfo,
MeshParametersComponent meshParameters,
ErosionParametersComponent erosionParameters)
{
var mapSize = meshParameters.MapResolution;
var brushRadius = erosionParameters.ErosionBrushRadius;
var verts = new Vector3[mapSize * mapSize];
var triangles = new int[(mapSize - 1) * (mapSize - 1) * 6];
for (var i = 0; i < mapSize * mapSize; i++)
{
var x = i % mapSize;
var y = i / mapSize;
var borderedMapIndex = (y + brushRadius) * mapInfo.MapSizeWithBorder + x + brushRadius;
var meshMapIndex = y * mapSize + x;
var percent = new Vector2(x / (mapSize - 1f), y / (mapSize - 1f));
var pos = new Vector3(percent.x * 2 - 1, 0, percent.y * 2 - 1) * meshParameters.Scale;
var normalizedHeight = mapInfo.Map[borderedMapIndex];
pos += Vector3.up * normalizedHeight * meshParameters.ElevationScale;
verts[meshMapIndex] = pos;
if (ConstructMeshHelper.IsInside(mapSize, x, y))
{
ConstructMeshHelper.ConstructTriangles(x, y, mapSize, meshMapIndex, triangles);
}
}
if (mapInfo.Mesh == null)
{
mapInfo.Mesh = new Mesh();
}
else
{
mapInfo.Mesh.Clear();
}
mapInfo.Mesh.indexFormat = UnityEngine.Rendering.IndexFormat.UInt32;
mapInfo.Mesh.vertices = verts;
mapInfo.Mesh.triangles = triangles;
mapInfo.Mesh.RecalculateNormals();
var(meshFilter, meshRenderer) = AssignMeshComponents();
meshFilter.sharedMesh = mapInfo.Mesh;
meshRenderer.sharedMaterial = meshParameters.Material;
}
private void SetErosionParameters(
ErosionParametersComponent erosionParameters, MapInfoComponent mapInfo, Brush brush)
{
var erosion = erosionParameters.Erosion;
erosion.SetInt("borderSize", erosionParameters.ErosionBrushRadius);
erosion.SetInt("mapSize", mapInfo.MapSizeWithBorder);
erosion.SetInt("brushLength", brush.IndexOffsets.Count);
erosion.SetInt("maxLifetime", erosionParameters.MaxLifetime);
erosion.SetFloat("inertia", erosionParameters.Inertia);
erosion.SetFloat("sedimentCapacityFactor", erosionParameters.SedimentCapacityFactor);
erosion.SetFloat("minSedimentCapacity", erosionParameters.MinSedimentCapacity);
erosion.SetFloat("depositSpeed", erosionParameters.DepositSpeed);
erosion.SetFloat("erodeSpeed", erosionParameters.ErodeSpeed);
erosion.SetFloat("evaporateSpeed", erosionParameters.EvaporateSpeed);
erosion.SetFloat("gravity", erosionParameters.Gravity);
erosion.SetFloat("startSpeed", erosionParameters.StartSpeed);
erosion.SetFloat("startWater", erosionParameters.StartWater);
}
private void Erode(
ErosionParametersComponent erosionParameters,
MeshParametersComponent meshParameters,
MapInfoComponent mapInfo)
{
const int maxThreadCount = 65535;
var brush = GeneralHelper.CreateBrush(erosionParameters, meshParameters.MapResolution);
var brushShader = new BrushShader()
{
IndexBuffer = GeneralHelper.GetBufferFor(brush.IndexOffsets, erosionParameters.Erosion,
"brushIndices"),
WeightBuffer =
GeneralHelper.GetBufferFor(brush.Weights, erosionParameters.Erosion, "brushWeights")
};
var randomIndices = GeneralHelper.GenerateIndices(
erosionParameters.ErosionIterationCount,
erosionParameters.ErosionBrushRadius,
meshParameters.MapResolution);
var randomIndexBuffer = GeneralHelper.GetBufferFor(randomIndices, erosionParameters.Erosion, "randomIndices");
var mapBuffer = GeneralHelper.GetBufferFor(mapInfo.Map, erosionParameters.Erosion, "map");
SetErosionParameters(erosionParameters, mapInfo, brush);
erosionParameters.Erosion.Dispatch(
0,
Math.Min(erosionParameters.ErosionIterationCount / 1024, maxThreadCount),
1,
1);
mapBuffer.GetData(mapInfo.Map);
GeneralHelper.ReleaseBuffers(new List <ComputeBuffer>()
{
brushShader.IndexBuffer,
brushShader.WeightBuffer,
mapBuffer,
randomIndexBuffer
});
}
