/// <summary>
/// Stolen from MeshBuilder class, maybe make this static method there public...
/// </summary>
/// <param name="positions"></param>
/// <param name="triangleIndices"></param>
/// <param name="normals"></param>
private static void ComputeNormals(Vector3Collection positions, IntCollection triangleIndices, out Vector3Collection normals)
{
normals = new Vector3Collection(positions.Count);
normals.AddRange(Enumerable.Repeat(Vector3.Zero, positions.Count));
for (int t = 0; t < triangleIndices.Count; t += 3)
{
var i1 = triangleIndices[t];
var i2 = triangleIndices[t + 1];
var i3 = triangleIndices[t + 2];
var v1 = positions[i1];
var v2 = positions[i2];
var v3 = positions[i3];
var p1 = v2 - v1;
var p2 = v3 - v1;
var n = Vector3.Cross(p1, p2);
// angle
p1.Normalize();
p2.Normalize();
var a = (float)Math.Acos(Vector3.Dot(p1, p2));
n.Normalize();
normals[i1] += (a * n);
normals[i2] += (a * n);
normals[i3] += (a * n);
}
for (int i = 0; i < normals.Count; i++)
{
var n = normals[i];
n.Normalize();
normals[i] = n;
}
}
public static MeshGeometry3D Merge(params MeshGeometry3D[] meshes)
{
var positions = new Vector3Collection();
var indices = new IntCollection();
var normals = meshes.All(x => x.Normals != null) ? new Vector3Collection() : null;
var colors = meshes.All(x => x.Colors != null) ? new Color4Collection() : null;
var textureCoods = meshes.All(x => x.TextureCoordinates != null) ? new Vector2Collection() : null;
var tangents = meshes.All(x => x.Tangents != null) ? new Vector3Collection() : null;
var bitangents = meshes.All(x => x.BiTangents != null) ? new Vector3Collection() : null;
int index = 0;
foreach (var part in meshes)
{
positions.AddRange(part.Positions);
indices.AddRange(part.Indices.Select(x => x + index));
index += part.Positions.Count;
}
if (normals != null)
{
normals = new Vector3Collection(meshes.SelectMany(x => x.Normals));
}
if (colors != null)
{
colors = new Color4Collection(meshes.SelectMany(x => x.Colors));
}
if (textureCoods != null)
{
textureCoods = new Vector2Collection(meshes.SelectMany(x => x.TextureCoordinates));
}
if (tangents != null)
{
tangents = new Vector3Collection(meshes.SelectMany(x => x.Tangents));
}
if (bitangents != null)
{
bitangents = new Vector3Collection(meshes.SelectMany(x => x.BiTangents));
}
var mesh = new MeshGeometry3D()
{
Positions = positions,
Indices = indices,
};
mesh.Normals = normals;
mesh.Colors = colors;
mesh.TextureCoordinates = textureCoods;
mesh.Tangents = tangents;
mesh.BiTangents = bitangents;
return(mesh);
}
public static BoneSkinnedMeshGeometry3D CreateSkeletonMesh(IList <Animations.Bone> bones, float scale = 1f)
{
var builder = new MeshBuilder(true, false);
builder.AddPyramid(new Vector3(0, scale / 2, 0), Vector3.UnitZ, Vector3.UnitY, scale, 0, true);
var singleBone = builder.ToMesh();
var boneIds = new List <BoneIds>();
var positions = new Vector3Collection(bones.Count * singleBone.Positions.Count);
var tris = new IntCollection(bones.Count * singleBone.Indices.Count);
int offset = 0;
for (int i = 0; i < bones.Count; ++i)
{
if (bones[i].ParentIndex >= 0)
{
int currPos = positions.Count;
tris.AddRange(singleBone.Indices.Select(x => x + offset));
int j = 0;
for (; j < singleBone.Positions.Count - 6; j += 3)
{
positions.Add(Vector3.TransformCoordinate(singleBone.Positions[j], bones[bones[i].ParentIndex].BindPose));
positions.Add(Vector3.TransformCoordinate(singleBone.Positions[j + 1], bones[bones[i].ParentIndex].BindPose));
positions.Add(bones[i].BindPose.TranslationVector);
boneIds.Add(new BoneIds()
{
Bone1 = bones[i].ParentIndex, Weights = new Vector4(1, 0, 0, 0)
});
boneIds.Add(new BoneIds()
{
Bone1 = bones[i].ParentIndex, Weights = new Vector4(1, 0, 0, 0)
});
boneIds.Add(new BoneIds()
{
Bone1 = i, Weights = new Vector4(1, 0, 0, 0)
});
}
for (; j < singleBone.Positions.Count; ++j)
{
positions.Add(Vector3.TransformCoordinate(singleBone.Positions[j], bones[bones[i].ParentIndex].BindPose));
boneIds.Add(new BoneIds()
{
Bone1 = bones[i].ParentIndex, Weights = new Vector4(1, 0, 0, 0)
});
}
offset += singleBone.Positions.Count;
}
}
builder = new MeshBuilder(true, false);
for (int i = 0; i < bones.Count; ++i)
{
int currPos = builder.Positions.Count;
builder.AddSphere(Vector3.Zero, scale / 2, 12, 12);
for (int j = currPos; j < builder.Positions.Count; ++j)
{
builder.Positions[j] = Vector3.TransformCoordinate(builder.Positions[j], bones[i].BindPose);
boneIds.Add(new BoneIds()
{
Bone1 = i, Weights = new Vector4(1, 0, 0, 0)
});
}
}
positions.AddRange(builder.Positions);
tris.AddRange(builder.TriangleIndices.Select(x => x + offset));
var mesh = new BoneSkinnedMeshGeometry3D()
{
Positions = positions, Indices = tris, VertexBoneIds = boneIds
};
mesh.Normals = mesh.CalculateNormals();
return(mesh);
}
private static void ComputeNormals(Vector3Collection positions, IntCollection triangleIndices, out Vector3Collection normals)
{
normals = new Vector3Collection(positions.Count);
normals.AddRange(Enumerable.Repeat(Vector3.Zero, positions.Count));
for (int t = 0; t < triangleIndices.Count; t += 3)
{
var i1 = triangleIndices[t];
var i2 = triangleIndices[t + 1];
var i3 = triangleIndices[t + 2];
var v1 = positions[i1];
var v2 = positions[i2];
var v3 = positions[i3];
var p1 = v2 - v1;
var p2 = v3 - v1;
var n = Vector3.Cross(p1, p2);
// angle
p1.Normalize();
p2.Normalize();
var a = (float)Math.Acos(Vector3.Dot(p1, p2));
n.Normalize();
normals[i1] += (a * n);
normals[i2] += (a * n);
normals[i3] += (a * n);
}
for (int i = 0; i < normals.Count; i++)
{
normals[i].Normalize();
}
}
