/// <summary>
/// Sets the given hairmesh into the given index.
/// NOTE: TressFX only supports indices 0-3 (so max. 4 meshes).
/// </summary>
/// <param name="index"></param>
/// <param name="mesh"></param>
public void SetHairMesh(int index, HairMesh mesh)
{
if (index >= 0 && index <= 3)
{
this.meshes[index] = mesh;
}
else
{
throw new IndexOutOfRangeException("TressFX only supports mesh indices between including 0 and 3");
}
}
/// <summary>
/// Implicitly initializes the indices of this hair.
/// This calculates the indices automatically
/// </summary>
/// <param name="lineIndices"></param>
/// <param name="triangleIndices"></param>
public void CreateIndices()
{
List <int> lineIndices = new List <int>();
List <int> triangleIndices = new List <int>();
int id = 0;
// Iterate through every mesh and every strand and every vertex and generate the indices for them.
for (int i = 0; i < this.meshes.Length; i++)
{
HairMesh currentMesh = this.meshes[i];
if (currentMesh == null)
{
continue;
}
for (int j = 0; j < currentMesh.strandCount; j++)
{
HairStrand currentStrand = currentMesh.strands[j];
for (int k = 0; k < currentStrand.vertices.Count - 1; k++)
{
HairStrandVertex currentVertex = currentStrand.vertices[k];
// Append line indices
lineIndices.Add(id);
lineIndices.Add(id + 1);
// Append triangle indices
triangleIndices.Add(2 * id);
triangleIndices.Add(2 * id + 1);
triangleIndices.Add(2 * id + 2);
triangleIndices.Add(2 * id + 2);
triangleIndices.Add(2 * id + 1);
triangleIndices.Add(2 * id + 3);
id++;
}
id++;
}
}
// Set indices
this.lineIndices = lineIndices.ToArray();
this.triangleIndices = triangleIndices.ToArray();
}
/// <summary>
/// This is called in PrepareSimulationParameters().
/// It may deletes some hairs in order to avoid branching in the compute shader.
/// </summary>
private void BranchingAvoidance(uint threadGroupSize = 64)
{
// Prepare
uint loadedNumStrands = (uint)this.strandCount;
uint deleteStrands = loadedNumStrands % threadGroupSize;
// Delete last hairs
// Get last mesh
HairMesh lastMesh = null;
foreach (HairMesh m in this.meshes)
{
if (m != null)
{
lastMesh = m;
}
}
for (uint i = deleteStrands; i > 0; i--)
{
// Remove last hair
lastMesh.strands.RemoveAt(lastMesh.strands.Count - 1);
}
}
/// <summary>
/// Sets the given hairmesh into the given index.
/// NOTE: TressFX only supports indices 0-3 (so max. 4 meshes).
/// </summary>
/// <param name="index"></param>
/// <param name="mesh"></param>
public void SetHairMesh(int index, HairMesh mesh)
{
if (index >= 0 && index <= 3)
this.meshes[index] = mesh;
else
throw new IndexOutOfRangeException("TressFX only supports mesh indices between including 0 and 3");
}
