/// <summary>
/// https://github.com/vrm-c/UniVRM/issues/800
///
/// SubMesh 単位に分割する。
/// SubMesh を Gltf の Primitive に対応させる。
/// </summary>
/// <param name="mesh"></param>
/// <param name="materials"></param>
/// <param name="storage"></param>
/// <param name="gltfMesh"></param>
/// <param name="option"></param>
static IEnumerable <glTFPrimitives> ExportMeshDivided(this VrmLib.Mesh mesh, List <object> materials, Vrm10Storage storage, ExportArgs option)
{
var bufferIndex = 0;
var usedIndices = new List <int>();
var meshIndices = SpanLike.CopyFrom(mesh.IndexBuffer.GetAsIntArray());
var positions = mesh.VertexBuffer.Positions.GetSpan <UnityEngine.Vector3>().ToArray();
var normals = mesh.VertexBuffer.Normals.GetSpan <UnityEngine.Vector3>().ToArray();
var uv = mesh.VertexBuffer.TexCoords.GetSpan <UnityEngine.Vector2>().ToArray();
var hasSkin = mesh.VertexBuffer.Weights != null;
var weights = mesh.VertexBuffer.Weights?.GetSpan <UnityEngine.Vector4>().ToArray();
var joints = mesh.VertexBuffer.Joints?.GetSpan <SkinJoints>().ToArray();
Func <int, int> getJointIndex = default;
if (hasSkin)
{
getJointIndex = i =>
{
return(i);
};
}
foreach (var submesh in mesh.Submeshes)
{
var indices = meshIndices.Slice(submesh.Offset, submesh.DrawCount).ToArray();
var hash = new HashSet <int>(indices);
// mesh
// index の順に attributes を蓄える
var buffer = new MeshExportUtil.VertexBuffer(indices.Length, getJointIndex);
usedIndices.Clear();
for (int k = 0; k < positions.Length; ++k)
{
if (hash.Contains(k))
{
// indices から参照される頂点だけを蓄える
usedIndices.Add(k);
buffer.Push(k, positions[k], normals[k], uv[k]);
if (getJointIndex != null)
{
var j = joints[k];
var w = weights[k];
var boneWeight = new UnityEngine.BoneWeight
{
boneIndex0 = j.Joint0,
boneIndex1 = j.Joint1,
boneIndex2 = j.Joint2,
boneIndex3 = j.Joint3,
weight0 = w.x,
weight1 = w.y,
weight2 = w.z,
weight3 = w.w,
};
buffer.Push(boneWeight);
}
}
}
var materialIndex = submesh.Material;
var gltfPrimitive = buffer.ToGltfPrimitive(storage.Gltf, bufferIndex, materialIndex, indices);
// blendShape
for (int j = 0; j < mesh.MorphTargets.Count; ++j)
{
var blendShape = new MeshExportUtil.BlendShapeBuffer(indices.Length);
// index の順に attributes を蓄える
var morph = mesh.MorphTargets[j];
var blendShapePositions = morph.VertexBuffer.Positions.GetSpan <UnityEngine.Vector3>();
SpanLike <UnityEngine.Vector3>?blendShapeNormals = default;
if (morph.VertexBuffer.Normals != null)
{
blendShapeNormals = morph.VertexBuffer.Normals.GetSpan <UnityEngine.Vector3>();
}
foreach (var k in usedIndices)
{
blendShape.Push(
blendShapePositions[k],
blendShapeNormals.HasValue ? blendShapeNormals.Value[k] : UnityEngine.Vector3.zero
);
}
gltfPrimitive.targets.Add(blendShape.ToGltf(storage.Gltf, bufferIndex, !option.removeMorphNormal));
}
yield return(gltfPrimitive);
}
}
private static VrmLib.MeshGroup CreateMesh(UnityEngine.Mesh mesh, Renderer renderer, List <UnityEngine.Material> materials)
{
var meshGroup = new VrmLib.MeshGroup(mesh.name);
var vrmMesh = new VrmLib.Mesh();
vrmMesh.VertexBuffer = new VrmLib.VertexBuffer();
vrmMesh.VertexBuffer.Add(VrmLib.VertexBuffer.PositionKey, ToBufferAccessor(mesh.vertices));
if (mesh.boneWeights.Length == mesh.vertexCount)
{
vrmMesh.VertexBuffer.Add(
VrmLib.VertexBuffer.WeightKey,
ToBufferAccessor(mesh.boneWeights.Select(x =>
new Vector4(x.weight0, x.weight1, x.weight2, x.weight3)).ToArray()
));
vrmMesh.VertexBuffer.Add(
VrmLib.VertexBuffer.JointKey,
ToBufferAccessor(mesh.boneWeights.Select(x =>
new SkinJoints((ushort)x.boneIndex0, (ushort)x.boneIndex1, (ushort)x.boneIndex2, (ushort)x.boneIndex3)).ToArray()
));
}
if (mesh.uv.Length == mesh.vertexCount)
{
vrmMesh.VertexBuffer.Add(VrmLib.VertexBuffer.TexCoordKey, ToBufferAccessor(mesh.uv));
}
if (mesh.normals.Length == mesh.vertexCount)
{
vrmMesh.VertexBuffer.Add(VrmLib.VertexBuffer.NormalKey, ToBufferAccessor(mesh.normals));
}
if (mesh.colors.Length == mesh.vertexCount)
{
vrmMesh.VertexBuffer.Add(VrmLib.VertexBuffer.ColorKey, ToBufferAccessor(mesh.colors));
}
vrmMesh.IndexBuffer = ToBufferAccessor(mesh.triangles);
int offset = 0;
for (int i = 0; i < mesh.subMeshCount; i++)
{
#if UNITY_2019
var subMesh = mesh.GetSubMesh(i);
try
{
vrmMesh.Submeshes.Add(new VrmLib.Submesh(offset, subMesh.indexCount, materials.IndexOf(renderer.sharedMaterials[i])));
}
catch (Exception ex)
{
Debug.LogError(ex);
}
offset += subMesh.indexCount;
#else
var triangles = mesh.GetTriangles(i);
try
{
vrmMesh.Submeshes.Add(new VrmLib.Submesh(offset, triangles.Length, materials.IndexOf(renderer.sharedMaterials[i])));
}
catch (Exception ex)
{
Debug.LogError(ex);
}
offset += triangles.Length;
#endif
}
for (int i = 0; i < mesh.blendShapeCount; i++)
{
var blendShapeVertices = mesh.vertices;
var usePosition = blendShapeVertices != null && blendShapeVertices.Length > 0;
var blendShapeNormals = mesh.normals;
var useNormal = usePosition && blendShapeNormals != null && blendShapeNormals.Length == blendShapeVertices.Length;
// var useNormal = usePosition && blendShapeNormals != null && blendShapeNormals.Length == blendShapeVertices.Length && !exportOnlyBlendShapePosition;
var blendShapeTangents = mesh.tangents.Select(y => (Vector3)y).ToArray();
//var useTangent = usePosition && blendShapeTangents != null && blendShapeTangents.Length == blendShapeVertices.Length;
// var useTangent = false;
var frameCount = mesh.GetBlendShapeFrameCount(i);
mesh.GetBlendShapeFrameVertices(i, frameCount - 1, blendShapeVertices, blendShapeNormals, null);
if (usePosition)
{
var morphTarget = new VrmLib.MorphTarget(mesh.GetBlendShapeName(i));
morphTarget.VertexBuffer = new VrmLib.VertexBuffer();
morphTarget.VertexBuffer.Add(VrmLib.VertexBuffer.PositionKey, ToBufferAccessor(blendShapeVertices));
vrmMesh.MorphTargets.Add(morphTarget);
}
}
meshGroup.Meshes.Add(vrmMesh);
return(meshGroup);
}