public async Task <Mesh> Build(Terrain terrain, List <Texture2D> alphaMaps, MassiveGrassProfile profile, List <Element> elements)
{
var terrainData = terrain.terrainData;
var w = terrainData.alphamapWidth;
var h = terrainData.alphamapHeight;
var meshData = new MeshData(elements.Count, 2);
var actualCount = 0;
for (var i = 0; i < elements.Count; i++)
{
var element = elements[i];
var layer = profile.PaintTextureIndex[0];
var alpha = alphaMaps[layer].GetPixel(
Mathf.RoundToInt((float)w * element.normalizedPosition.y),
Mathf.RoundToInt((float)h * element.normalizedPosition.x)).a;
if (alpha > profile.AlphaMapThreshold)
{
AddQuad(meshData, profile, element, actualCount++);
}
}
var mesh = new Mesh();
mesh.vertices = meshData.vertices.Take(4 * actualCount).ToArray();
mesh.normals = meshData.normals.Take(4 * actualCount).ToArray();
mesh.triangles = meshData.triangles.Take(6 * actualCount).ToArray();
mesh.colors = meshData.colors.Take(4 * actualCount).ToArray();
mesh.SetUVs(0, meshData.uvs.Take(4 * actualCount).ToList());
return(mesh);
}
private void AddQuad(MeshData meshData, MassiveGrassProfile profile, Element element, int index)
{
var vOrigin = index * 4;
var iOrigin = index * 6;
var rand = ParkAndMiller.Get(element.index);
Quaternion normalRot = Quaternion.LookRotation(element.normal);
Quaternion slant = Quaternion.AngleAxis(profile.Slant * 90f * (rand - 0.5f), Vector3.right);
Quaternion slantWeak = Quaternion.AngleAxis(profile.Slant * 45f * (rand - 0.5f), Vector3.right);
Quaternion upRot = Quaternion.AngleAxis(360f * rand, Vector3.up);
Quaternion rot = normalRot *
Quaternion.AngleAxis(90f, Vector3.right) *
upRot *
slant;
var scale = profile.Scale;
var p1 = rot * new Vector3(-0.5f * scale.x, 1f * scale.y, 0f);
var p2 = rot * new Vector3(0.5f * scale.x, 1f * scale.y, 0f);
var p3 = rot * new Vector3(0.5f * scale.x, 0f, 0f);
var p4 = rot * new Vector3(-0.5f * scale.x, 0f, 0f);
var normal = element.normal;
var color = Color.Lerp(Color.white, Color.yellow, rand);
meshData.vertices[vOrigin + 0] = element.position + p1;
meshData.vertices[vOrigin + 1] = element.position + p2;
meshData.vertices[vOrigin + 2] = element.position + p3;
meshData.vertices[vOrigin + 3] = element.position + p4;
meshData.normals[vOrigin + 0] = normal * 1f;
meshData.normals[vOrigin + 1] = normal * 1f;
meshData.normals[vOrigin + 2] = normal * 0.5f;
meshData.normals[vOrigin + 3] = normal * 0.5f;
meshData.uvs[vOrigin + 0] = new Vector4(0f, 1f, 0f, 0f);
meshData.uvs[vOrigin + 1] = new Vector4(1f, 1f, 0f, 0f);
meshData.uvs[vOrigin + 2] = new Vector4(1f, 0f, 0f, 0f);
meshData.uvs[vOrigin + 3] = new Vector4(0f, 0f, 0f, 0f);
meshData.colors[vOrigin + 0] = color;
meshData.colors[vOrigin + 1] = color;
meshData.colors[vOrigin + 2] = color;
meshData.colors[vOrigin + 3] = color;
meshData.triangles[iOrigin + 0] = vOrigin + 0;
meshData.triangles[iOrigin + 1] = vOrigin + 1;
meshData.triangles[iOrigin + 2] = vOrigin + 2;
meshData.triangles[iOrigin + 3] = vOrigin + 2;
meshData.triangles[iOrigin + 4] = vOrigin + 3;
meshData.triangles[iOrigin + 5] = vOrigin + 0;
}
public void OnBeginRender(
Camera camera,
MassiveGrassProfile profile,
Terrain terrain,
Texture2D[] alphaMaps,
int maxParallelJobCount)
{
if (profile == null)
{
return;
}
if (!renderers.ContainsKey(profile))
{
renderers[profile] = new MassiveGrassRenderer(
camera,
terrain,
alphaMaps,
profile,
maxParallelJobCount);
}
renderers[profile].OnBeginRender();
}
public void OnBeginRender(
Camera camera,
MassiveGrassProfile profile,
Terrain terrain,
List <Texture2D> alphaMaps,
int maxParallelJobCount)
{
if (profile == null)
{
return;
}
if (!renderers.ContainsKey(profile))
{
renderers[profile] = new MassiveGrassRenderer(
camera,
terrain,
alphaMaps,
profile,
maxParallelJobCount);
Debug.Log($" renderer for {profile} created on {camera}");
}
renderers[profile].OnBeginRender();
}
