private static VrmLib.BufferAccessor ToBufferAccessor <T>(T[] value, VrmLib.AccessorValueType valueType, VrmLib.AccessorVectorType vectorType) where T : struct
{
var span = SpanLike.CopyFrom(value);
return(new VrmLib.BufferAccessor(
span.Bytes,
valueType,
vectorType,
value.Length
));
}
/// <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);
}
}
