static ComputeBuffer GenerateMeshData(MeshIndex meshIndex)
{
var mesh = meshIndex.Mesh;
var uvChannel = meshIndex.UvChannel;
//Build mesh data structure
mesh.GetVertices(s_verts);
mesh.GetNormals(s_normals);
mesh.GetTriangles(s_triangles, 0);
int count = s_triangles.Count / 3;
uvChannel = Mathf.Clamp(uvChannel, 0, 4);
mesh.GetUVs(uvChannel, s_uvs);
//TODO: Reuse face somehow?
ComputeBuffer buffer;
if (!s_meshStore.TryGetValue(meshIndex, out buffer))
{
buffer = new ComputeBuffer(count, ParticleComponent.SizeOf <Face>());
s_meshStore[meshIndex] = buffer;
}
else
{
if (buffer == null || buffer.count != count)
{
if (buffer != null)
{
buffer.Dispose();
}
buffer = new ComputeBuffer(count, ParticleComponent.SizeOf <Face>());
s_meshStore[meshIndex] = buffer;
}
}
while (s_faces.Length < buffer.count)
{
Array.Resize(ref s_faces, s_faces.Length * 2);
}
float totalArea = 0.0f;
//TODO: Can't we parralise this easily?
for (int i = 0; i < count; ++i)
{
int i3 = i * 3;
int t0 = s_triangles[i3 + 0];
int t1 = s_triangles[i3 + 1];
int t2 = s_triangles[i3 + 2];
s_faces[i] = new Face {
a = s_verts[t0],
b = s_verts[t1],
c = s_verts[t2],
na = s_normals[t0],
nb = s_normals[t1],
nc = s_normals[t2],
uva = s_uvs[t0],
uvb = s_uvs[t1],
uvc = s_uvs[t2]
};
//Calculate area of triangle manually.
//Equivalent to 0.5 * | (a - b) x (a - c) |
float x1 = s_verts[t0].x - s_verts[t1].x;
float x2 = s_verts[t0].y - s_verts[t1].y;
float x3 = s_verts[t0].z - s_verts[t1].z;
float y1 = s_verts[t0].x - s_verts[t2].x;
float y2 = s_verts[t0].y - s_verts[t2].y;
float y3 = s_verts[t0].z - s_verts[t2].z;
float r1 = x2 * y3 - x3 * y2;
float r2 = x3 * y1 - x1 * y3;
float r3 = x1 * y2 - x2 * y1;
float area = 0.5f * Mathf.Sqrt(r1 * r1 + r2 * r2 + r3 * r3);
s_faces[i].cweight = area;
totalArea += area;
}
float cumulative = 0;
for (int i = 0; i < count; ++i)
{
cumulative += s_faces[i].cweight / totalArea;
s_faces[i].cweight = cumulative;
}
buffer.SetData(s_faces, 0, 0, count);
return(buffer);
}
void GenerateMeshData()
{
//Data already cached!
if (TCParticleGlobalRender.MeshStore.ContainsKey(emitMesh))
{
return;
}
//Build mesh data structure
Vector3[] vertices = emitMesh.vertices;
Vector3[] normals = emitMesh.normals;
int[] triangles = emitMesh.triangles;
int count = triangles.Length / 3;
List <Vector2> uvs = new List <Vector2>();
uvChannel = Mathf.Clamp(uvChannel, 0, 4);
emitMesh.GetUVs(uvChannel, uvs);
var faces = new Face[count];
for (int i = 0; i < count; ++i)
{
int t0 = triangles[i * 3 + 0];
int t1 = triangles[i * 3 + 1];
int t2 = triangles[i * 3 + 2];
faces[i] = new Face {
a = vertices[t0],
b = vertices[t1],
c = vertices[t2],
na = normals[t0],
nb = normals[t1],
nc = normals[t2],
uva = uvs[t0],
uvb = uvs[t1],
uvc = uvs[t2]
};
//Do we accumulate area for normlisation?
if (normalizeArea)
{
float area = Vector3.Cross(faces[i].a - faces[i].b, faces[i].c - faces[i].a).magnitude / 2.0f;
faces[i].cweight = area;
m_totalArea += area;
}
else
{
faces[i].cweight = 0.0f;
}
}
if (normalizeArea)
{
float cumulative = 0;
for (int i = 0; i < count; ++i)
{
cumulative += faces[i].cweight / m_totalArea;
faces[i].cweight = cumulative;
}
}
var buffer = new ComputeBuffer(count, ParticleComponent.SizeOf <Face>());
buffer.SetData(faces);
TCParticleGlobalRender.MeshStore[emitMesh] = buffer;
}
