private (Vector3[], Vector3[]) smoothTerrainVerticesAndNormals(MeshGenerator.Data data, Vector3 axisA, Vector3 axisB)
{
Vector3[] vertices = new Vector3[(MeshGenerator.CHUNK_SIZE + 1) * (MeshGenerator.CHUNK_SIZE + 1)];
Vector3[] normals = new Vector3[(MeshGenerator.CHUNK_SIZE + 1) * (MeshGenerator.CHUNK_SIZE + 1)];
float stepSize = (data.chunkLength + data.chunkLength) / MeshGenerator.CHUNK_SIZE;
var axisAOffset = (axisA * data.chunkLength);
var axisBOffset = (axisB * data.chunkLength);
var planetRadius = (float)(Math.Pow(2, Planet.PLANET_SIZE) * Planet.SCALE);
for (int y = 0; y < MeshGenerator.CHUNK_SIZE + 1; y++)
{
for (int x = 0; x < MeshGenerator.CHUNK_SIZE + 1; x++)
{
var pointOnCube = computePointOnCube(x, y);
var pointOnUnitSphere = Vector3.Normalize(pointOnCube);
var pointOnSphere = pointOnUnitSphere * planetRadius;
var elevatedPointOnSphere = pointOnSphere * (1.0f + noiseFilter.Evaluate(pointOnSphere) * Planet.SCALE);
vertices[y * (MeshGenerator.CHUNK_SIZE + 1) + x] = elevatedPointOnSphere;
Vector3 leftNeighbor;
Vector3 topNeighbor;
if (x > 0 && y > 0)
{
leftNeighbor = vertices[y * (MeshGenerator.CHUNK_SIZE + 1) + (x - 1)];
topNeighbor = vertices[(y - 1) * (MeshGenerator.CHUNK_SIZE + 1) + x];
}
else
{
var leftNeighborOnSphere = Vector3.Normalize(computePointOnCube(x - 1, y)) * planetRadius;
leftNeighbor = leftNeighborOnSphere * (1.0f + noiseFilter.Evaluate(leftNeighborOnSphere) * Planet.SCALE);
var topNeighborOnSphere = Vector3.Normalize(computePointOnCube(x, y - 1)) * planetRadius;
topNeighbor = topNeighborOnSphere * (1.0f + noiseFilter.Evaluate(topNeighborOnSphere) * Planet.SCALE);
}
normals[y * (MeshGenerator.CHUNK_SIZE + 1) + x] += Vector3.Cross(topNeighbor - elevatedPointOnSphere, leftNeighbor - elevatedPointOnSphere);
var rightNeighborOnSphere = Vector3.Normalize(computePointOnCube(x + 1, y)) * planetRadius;
var rightNeighbor = rightNeighborOnSphere * (1.0f + noiseFilter.Evaluate(rightNeighborOnSphere) * Planet.SCALE);
var bottomNeighborOnSphere = Vector3.Normalize(computePointOnCube(x, y + 1)) * planetRadius;
var bottomNeighbor = bottomNeighborOnSphere * (1.0f + noiseFilter.Evaluate(bottomNeighborOnSphere) * Planet.SCALE);
normals[y * (MeshGenerator.CHUNK_SIZE + 1) + x] += Vector3.Cross(bottomNeighbor - elevatedPointOnSphere, rightNeighbor - elevatedPointOnSphere);
}
}
Vector3 computePointOnCube(int x, int y)
{
return(axisA * (y * stepSize) + axisB * (x * stepSize) + data.center - axisAOffset - axisBOffset);
}
for (int i = 0; i < normals.Length; i++)
{
normals[i] = Vector3.Normalize(normals[i]);
}
return(vertices, normals);
}
private Mesh smoothTerrainMesh(MeshGenerator.Data data, Vector3 axisA, Vector3 axisB)
{
var(vertices, normals) = smoothTerrainVerticesAndNormals(data, axisA, axisB);
return(new Mesh()
{
vertices = vertices,
indices = IndicesLookup.Indices,
normals = normals
});
}
private Mesh blockTerrainMesh(MeshGenerator.Data data, Vector3 axisA, Vector3 axisB)
{
List <Vector3> vertices = new List <Vector3>();
List <int> indices = new List <int>();
var axisAOffset = (axisA * data.chunkLength);
var axisBOffset = (axisB * data.chunkLength);
float[] lastRowElevations = new float[MeshGenerator.CHUNK_SIZE];
float lastColumnElevation = 0.0f;
for (int y = 0; y < MeshGenerator.CHUNK_SIZE; y++)
{
for (int x = 0; x < MeshGenerator.CHUNK_SIZE; x++)
{
var middlePointOnCube = axisA * ((y + 0.5f) * BLOCK_HEIGHT) + axisB * ((x + 0.5f) * BLOCK_HEIGHT) + data.center - axisAOffset - axisBOffset;
var topLeftPointOnCube = middlePointOnCube + axisA * (BLOCK_HEIGHT * 0.5f) - axisB * (BLOCK_HEIGHT * 0.5f);
var topRightPointOnCube = middlePointOnCube + axisA * (BLOCK_HEIGHT * 0.5f) + axisB * (BLOCK_HEIGHT * 0.5f);
var bottomLeftPointOnCube = middlePointOnCube - axisA * (BLOCK_HEIGHT * 0.5f) - axisB * (BLOCK_HEIGHT * 0.5f);
var bottomRightPointOnCube = middlePointOnCube - axisA * (BLOCK_HEIGHT * 0.5f) + axisB * (BLOCK_HEIGHT * 0.5f);
// TODO: reuse points in next iteration
var topLeftPointOnSphere = Vector3.Normalize(topLeftPointOnCube);
var topRightPointOnSphere = Vector3.Normalize(topRightPointOnCube);
var bottomLeftPointOnSphere = Vector3.Normalize(bottomLeftPointOnCube);
var bottomRightPointOnSphere = Vector3.Normalize(bottomRightPointOnCube);
var scaledTopLeftPointOnSphere = topLeftPointOnSphere * PLANET_RADIUS;
var scaledTopRightPointOnSphere = topRightPointOnSphere * PLANET_RADIUS;
var scaledBottomLeftPointOnSphere = bottomLeftPointOnSphere * PLANET_RADIUS;
var scaledBottomRightPointOnSphere = bottomRightPointOnSphere * PLANET_RADIUS;
var elevation = 1.0f + this.elevation(x, y, axisA, axisB, axisAOffset, axisBOffset, data.center) * Planet.SCALE;
var elevatedTopLeft = scaledTopLeftPointOnSphere * elevation;
var elevatedTopRight = scaledTopRightPointOnSphere * elevation;
var elevatedBottomLeft = scaledBottomLeftPointOnSphere * elevation;
var elevatedBottomRight = scaledBottomRightPointOnSphere * elevation;
vertices.Add(elevatedTopLeft);
vertices.Add(elevatedTopRight);
vertices.Add(elevatedBottomLeft);
vertices.Add(elevatedBottomRight);
int vertexBlockStart = vertices.Count - 4;
indices.Add(vertexBlockStart + 0);
indices.Add(vertexBlockStart + 1);
indices.Add(vertexBlockStart + 2);
indices.Add(vertexBlockStart + 1);
indices.Add(vertexBlockStart + 3);
indices.Add(vertexBlockStart + 2);
if (y > 0)
{
var topElevation = lastRowElevations[x];
computeVerticalCubeFaces(
vertexBlockStart,
computeVertexBlockStart(x, y - 1),
elevation,
topElevation,
2,
3,
0,
1,
bottomLeftPointOnSphere,
bottomRightPointOnSphere,
vertices,
indices);
}
if (x > 0)
{
var leftElevation = lastColumnElevation;
computeVerticalCubeFaces(
vertexBlockStart,
vertices.Count - 8,
elevation,
leftElevation,
0,
2,
1,
3,
topLeftPointOnSphere,
bottomLeftPointOnSphere,
vertices,
indices);
}
lastColumnElevation = elevation;
lastRowElevations[x] = elevation;
}
}
int computeVertexBlockStart(int x, int y)
{
return((x + MeshGenerator.CHUNK_SIZE * y) * 4);
}
return(new Mesh()
{
vertices = vertices.ToArray(),
indices = indices.ToArray()
});
}
