/// <summary>
/// Triangulate an height map and generates a base of given height
/// </summary>
/// <param name="heightMap">Gridded set of points. Corrdinates can differ,
/// but height map should be organized a set of rows and columns</param>
/// <returns>TriangulationResult</returns>
public Triangulation GenerateTriangleMesh_Boxed(HeightMap heightMap
, BoxBaseThickness thickness, float zValue)
{
Triangulation triangulationResult = new Triangulation();
triangulationResult.NumIndices = ((heightMap.Width - 1) * 6) * (heightMap.Height - 1); // height map plane
triangulationResult.NumIndices += ((heightMap.Width - 1) * 6) * 2; // two sides
triangulationResult.NumIndices += ((heightMap.Height - 1) * 6) * 2; // two sizes
triangulationResult.NumIndices += 6; // bottom (two big triangles)
// Regular triangulation
triangulationResult.Positions = heightMap.Coordinates;
triangulationResult.Indices = TriangulateHeightMap_Internal(heightMap, true);
// Generate box vertices and trianglation
AddHeightMapBase(triangulationResult, heightMap, thickness, zValue);
return(triangulationResult);
}
private void AddHeightMapBase(Triangulation triangulation, HeightMap heightMap, BoxBaseThickness thickness, float zValue)
{
// bake coordinates to avoid executing the coords transfrom pipeline
var coords = heightMap.Coordinates.ToList();
int capacity = heightMap.Width * 2 + (heightMap.Height - 2) * 2;
var basePoints = new List <GeoPoint>(capacity);
var baseIndexes = new List <int>(capacity);
float baseElevation = 0;
switch (thickness)
{
case BoxBaseThickness.FromMinimumPoint:
baseElevation = (float)coords.Min(p => p.Elevation).GetValueOrDefault(0) - zValue;
break;
default:
case BoxBaseThickness.FixedElevation:
baseElevation = zValue;
break;
}
// x : 0 => width // y : 0
int baseIndex0 = coords.Count;
int baseIndex = baseIndex0;
for (int x = 0; x < heightMap.Width - 1; x++)
{
var pBase = coords[x].Clone();
pBase.Elevation = baseElevation;
basePoints.Add(pBase);
baseIndexes.Add(x);
baseIndexes.Add(baseIndex + 1);
baseIndexes.Add(baseIndex);
baseIndexes.Add(x + 1);
baseIndexes.Add(baseIndex + 1);
baseIndexes.Add(x);
baseIndex++;
}
// x : width // y : 0 => height
//
for (int y = 0; y < heightMap.Height - 1; y++)
{
int x = heightMap.Width - 1;
int index = x + y * heightMap.Width;
var pBase = coords[index].Clone();
pBase.Elevation = baseElevation;
basePoints.Add(pBase);
baseIndexes.Add(x + y * heightMap.Width);
baseIndexes.Add(baseIndex + 1);
baseIndexes.Add(baseIndex);
baseIndexes.Add(x + y * heightMap.Width);
baseIndexes.Add(x + (y + 1) * heightMap.Width);
baseIndexes.Add(baseIndex + 1);
baseIndex++;
}
//// x : width => 0 // y : height
for (int x = heightMap.Width - 1; x > 0; x--)
{
int index = x + (heightMap.Height - 1) * heightMap.Width;
var pBase = coords[index].Clone();
pBase.Elevation = baseElevation;
basePoints.Add(pBase);
baseIndexes.Add(index);
baseIndexes.Add(index - 1);
baseIndexes.Add(baseIndex);
baseIndexes.Add(index - 1);
baseIndexes.Add(baseIndex + 1);
baseIndexes.Add(baseIndex);
baseIndex++;
}
//// x : 0 // y : height => 0
for (int y = heightMap.Height - 1; y > 0; y--)
{
int x = 0;
int index = x + y * heightMap.Width;
var pBase = coords[index].Clone();
pBase.Elevation = baseElevation;
basePoints.Add(pBase);
// last base position is the first base generated
int nextBaseIndex = baseIndex + 1 > baseIndex0 + capacity - 1 ? baseIndex0 : baseIndex + 1;
baseIndexes.Add(x + y * heightMap.Width);
baseIndexes.Add(nextBaseIndex);
baseIndexes.Add(baseIndex);
baseIndexes.Add(x + y * heightMap.Width);
baseIndexes.Add(x + (y - 1) * heightMap.Width);
baseIndexes.Add(nextBaseIndex);
baseIndex++;
}
// base (2 big triangles)
baseIndexes.Add(baseIndex0);
baseIndexes.Add(baseIndex0 + heightMap.Width - 1);
baseIndexes.Add(baseIndex0 + heightMap.Width - 1 + heightMap.Height - 1);
baseIndexes.Add(baseIndex0);
baseIndexes.Add(baseIndex0 + heightMap.Width - 1 + heightMap.Height - 1);
baseIndexes.Add(baseIndex0 + 2 * (heightMap.Width - 1) + heightMap.Height - 1);
triangulation.Positions = triangulation.Positions.Concat(basePoints);
triangulation.NumPositions += basePoints.Count;
triangulation.Indices = triangulation.Indices.Concat(baseIndexes);
}
/// <summary>
/// Generate a triangle mesh from supplied height map, triangulating and optionaly mapping UVs
/// and generate sides and bottom (like a box where the top is the triangulated height map)
/// </summary>
/// <param name="heightMap">Height map.</param>
/// <param name="thickness">Determines how box height will be calculated</param>
/// <param name="zValue">Z value to apply for box calculation</param>
/// <returns></returns>
public MeshPrimitive GenerateTriangleMesh_Boxed(HeightMap heightMap, BoxBaseThickness thickness = BoxBaseThickness.FixedElevation, float zValue = 0f)
{
Triangulation triangulation = _meshService.GenerateTriangleMesh_Boxed(heightMap, thickness, zValue);
return(GenerateTriangleMesh(triangulation));
}
