private void UpdateMesh(Mesh m, GSubDivisionTree tree)
{
CreatePolygons(tree);
m.Clear();
m.SetVertices(GeneratedVertices);
m.SetTriangles(GeneratedTriangles, 0);
m.SetUVs(0, GeneratedUv);
m.SetColors(GeneratedVertexColors);
m.RecalculateBounds();
m.RecalculateNormals();
RecalculateTangentIfNeeded(m);
GeneratedVertices.Clear();
GeneratedTriangles.Clear();
GeneratedVertexColors.Clear();
GeneratedUv.Clear();
SetLastUpdatedTimeNow();
}
private void CreatePolygons(GSubDivisionTree tree)
{
int dispSeed = Terrain.TerrainData.Geometry.DisplacementSeed;
float dispStrength = Terrain.TerrainData.Geometry.DisplacementStrength;
Texture2D subdivMap = Terrain.TerrainData.Geometry.Internal_SubDivisionMap;
Vector2 uv0, uv1, uv2;
Vector3 v0, v1, v2;
float r;
Rand rand;
double radius;
int baseResolution = Terrain.TerrainData.Geometry.MeshBaseResolution;
int resolution = Terrain.TerrainData.Geometry.MeshResolution;
int level;
double triangleBaseLength = 1f / Terrain.TerrainData.Geometry.ChunkGridSize;
IGPolygonProcessor pp = Terrain.TerrainData.Geometry.PolygonProcessor;
GPolygon polygon = new GPolygon();
GeneratedUv.Clear();
GeneratedVertices.Clear();
GeneratedVertexColors.Clear();
GeneratedTriangles.Clear();
Vector3 terrainSize = new Vector3(
Terrain.TerrainData.Geometry.Width,
Terrain.TerrainData.Geometry.Height,
Terrain.TerrainData.Geometry.Length);
v0 = Vector3.zero;
v1 = Vector3.zero;
v2 = Vector3.zero;
tree.ForEachLeaf((n) =>
{
uv0 = n.V0;
uv1 = n.V1;
uv2 = n.V2;
if (dispStrength > 0)
{
if (uv0.x != 0 && uv0.x != 1 && uv0.y != 0 && uv0.y != 1)
{
r = subdivMap.GetPixelBilinear(uv0.x, uv0.y).r;
level = baseResolution + Mathf.Min(Mathf.FloorToInt(r / GCommon.SUB_DIV_STEP), resolution - baseResolution);
rand = new Rand(dispSeed + (int)(uv0.x * 1000 + uv0.y * 1000));
radius = 0.35 * dispStrength * triangleBaseLength * TriangleEdgeLength[level];
uv0.x = Mathf.Clamp01(uv0.x + (float)((rand.NextDouble() - 0.5) * radius));
uv0.y = Mathf.Clamp01(uv0.y + (float)((rand.NextDouble() - 0.5) * radius));
}
if (uv1.x != 0 && uv1.x != 1 && uv1.y != 0 && uv1.y != 1)
{
r = subdivMap.GetPixelBilinear(uv1.x, uv1.y).r;
level = baseResolution + Mathf.Min(Mathf.FloorToInt(r / GCommon.SUB_DIV_STEP), resolution - baseResolution);
rand = new Rand(dispSeed + (int)(uv1.x * 1000 + uv1.y * 1000));
radius = 0.35 * dispStrength * triangleBaseLength * TriangleEdgeLength[level];
uv1.x = Mathf.Clamp01(uv1.x + (float)((rand.NextDouble() - 0.5) * radius));
uv1.y = Mathf.Clamp01(uv1.y + (float)((rand.NextDouble() - 0.5) * radius));
}
if (uv2.x != 0 && uv2.x != 1 && uv2.y != 0 && uv2.y != 1)
{
r = subdivMap.GetPixelBilinear(uv2.x, uv2.y).r;
level = baseResolution + Mathf.Min(Mathf.FloorToInt(r / GCommon.SUB_DIV_STEP), resolution - baseResolution);
rand = new Rand(dispSeed + (int)(uv2.x * 1000 + uv2.y * 1000));
radius = 0.35 * dispStrength * triangleBaseLength * TriangleEdgeLength[level];
uv2.x = Mathf.Clamp01(uv2.x + (float)((rand.NextDouble() - 0.5) * radius));
uv2.y = Mathf.Clamp01(uv2.y + (float)((rand.NextDouble() - 0.5) * radius));
}
}
Vector4 h0 = Terrain.GetInterpolatedHeightMapSample(uv0);
Vector4 h1 = Terrain.GetInterpolatedHeightMapSample(uv1);
Vector4 h2 = Terrain.GetInterpolatedHeightMapSample(uv2);
if (h0.w >= 0.5f || h1.w >= 0.5f || h2.w >= 0.5f) //alpha channel for visibility
{
return;
}
if (pp != null)
{
polygon.Clear();
v0.Set(uv0.x * terrainSize.x, h0.x * terrainSize.y, uv0.y * terrainSize.z);
v1.Set(uv1.x * terrainSize.x, h1.x * terrainSize.y, uv1.y * terrainSize.z);
v2.Set(uv2.x * terrainSize.x, h2.x * terrainSize.y, uv2.y * terrainSize.z);
polygon.Vertices.Add(v0);
polygon.Vertices.Add(v1);
polygon.Vertices.Add(v2);
polygon.Uvs.Add(uv0);
polygon.Uvs.Add(uv1);
polygon.Uvs.Add(uv2);
polygon.Triangles.Add(0);
polygon.Triangles.Add(1);
polygon.Triangles.Add(2);
pp.Process(this, ref polygon);
int currentTrisIndex = GeneratedVertices.Count;
for (int i = 0; i < polygon.Triangles.Count; ++i)
{
GeneratedTriangles.Add(currentTrisIndex + polygon.Triangles[i]);
}
for (int i = 0; i < polygon.Vertices.Count; ++i)
{
GeneratedVertices.Add(polygon.Vertices[i]);
}
for (int i = 0; i < polygon.Uvs.Count; ++i)
{
GeneratedUv.Add(polygon.Uvs[i]);
}
if (polygon.VertexColors != null && polygon.VertexColors.Count > 0)
{
for (int i = 0; i < polygon.VertexColors.Count; ++i)
{
GeneratedVertexColors.Add(polygon.VertexColors[i]);
}
}
}
else
{
int currentTrisIndex = GeneratedVertices.Count;
GeneratedTriangles.Add(currentTrisIndex + 0);
GeneratedTriangles.Add(currentTrisIndex + 1);
GeneratedTriangles.Add(currentTrisIndex + 2);
v0.Set(uv0.x * terrainSize.x, h0.x * terrainSize.y, uv0.y * terrainSize.z);
v1.Set(uv1.x * terrainSize.x, h1.x * terrainSize.y, uv1.y * terrainSize.z);
v2.Set(uv2.x * terrainSize.x, h2.x * terrainSize.y, uv2.y * terrainSize.z);
GeneratedVertices.Add(v0);
GeneratedVertices.Add(v1);
GeneratedVertices.Add(v2);
GeneratedUv.Add(uv0);
GeneratedUv.Add(uv1);
GeneratedUv.Add(uv2);
}
});
//Convert vertices terrain local space to chunk local space.
//This way we can place the chunk pivot/origin point at the center of its region instead of the terrain pivot.
//Chunk position is set by the terrain component.
//This step is very important for other task such as level streaming and occlusion culling, etc.
//Special thank to Aleš Stupka for the contribution.
Matrix4x4 vertexTransformMatrix = Terrain.transform.localToWorldMatrix * transform.worldToLocalMatrix;
for (int i = 0; i < GeneratedVertices.Count; ++i)
{
GeneratedVertices[i] = vertexTransformMatrix.MultiplyPoint(GeneratedVertices[i]);
}
}
