private static Ai.Mesh CreateAiMeshFromSubMesh(SubMesh subMesh, Mesh mesh, Object obj, Ai.Scene aiScene, string name)
{
var aiMesh = new Ai.Mesh(name, Ai.PrimitiveType.Triangle);
if (mesh.Positions != null)
{
aiMesh.Vertices.Capacity = mesh.Positions.Length;
aiMesh.Vertices.AddRange(mesh.Positions.Select(x => x.ToAssimp()));
}
if (mesh.Normals != null)
{
aiMesh.Normals.Capacity = mesh.Normals.Length;
aiMesh.Normals.AddRange(mesh.Normals.Select(x => x.ToAssimp()));
}
for (int i = 0; i < 4; i++)
{
var texCoords = mesh.GetTexCoordsChannel(i);
if (texCoords == null)
{
continue;
}
aiMesh.TextureCoordinateChannels[i].Capacity = texCoords.Length;
aiMesh.TextureCoordinateChannels[i].AddRange(texCoords.Select(x => new Ai.Vector3D(x.ToAssimp(), 0)));
}
for (int i = 0; i < 2; i++)
{
var colors = mesh.GetColorsChannel(i);
if (colors == null)
{
continue;
}
aiMesh.VertexColorChannels[i].Capacity = colors.Length;
aiMesh.VertexColorChannels[i].AddRange(colors.Select(x => x.ToAssimp()));
}
if (mesh.BoneWeights != null)
{
for (int i = 0; i < subMesh.BoneIndices.Length; i++)
{
ushort boneIndex = subMesh.BoneIndices[i];
var bone = obj.Skin.Bones[boneIndex];
var aiBone = new Ai.Bone();
aiBone.Name = bone.Name;
aiBone.OffsetMatrix = bone.InverseBindPoseMatrix.ToAssimpTransposed();
for (int j = 0; j < mesh.BoneWeights.Length; j++)
{
var boneWeight = mesh.BoneWeights[j];
if (boneWeight.Index1 == i)
{
aiBone.VertexWeights.Add(new Ai.VertexWeight(j, boneWeight.Weight1));
}
if (boneWeight.Index2 == i)
{
aiBone.VertexWeights.Add(new Ai.VertexWeight(j, boneWeight.Weight2));
}
if (boneWeight.Index3 == i)
{
aiBone.VertexWeights.Add(new Ai.VertexWeight(j, boneWeight.Weight3));
}
if (boneWeight.Index4 == i)
{
aiBone.VertexWeights.Add(new Ai.VertexWeight(j, boneWeight.Weight4));
}
}
aiMesh.Bones.Add(aiBone);
}
}
var triangles = subMesh.GetTriangles();
aiMesh.Faces.Capacity = triangles.Count;
aiMesh.Faces.AddRange(triangles.Select(x =>
{
var aiFace = new Ai.Face();
aiFace.Indices.Capacity = 3;
aiFace.Indices.Add(( int )x.A);
aiFace.Indices.Add(( int )x.B);
aiFace.Indices.Add(( int )x.C);
return(aiFace);
}));
var material = obj.Materials[( int )subMesh.MaterialIndex];
int materialIndex = aiScene.Materials.FindIndex(x => x.Name == material.Name + "+" + obj.Name);
if (materialIndex == -1)
{
materialIndex = aiScene.Materials.FindIndex(x => x.Name == material.Name);
}
aiMesh.MaterialIndex = materialIndex;
return(aiMesh);
}