static unsafe InputAccess GetInputAccess(PointElementName name, List <PointElement> elements, byte *data, int stride)
{
foreach (var element in elements)
{
if (element.Name == name)
{
if (element.Type == PointElementType.Float || element.Type == PointElementType.Double)
{
int elementSize = PointElement.GetSize(element.Type);
return(new InputAccess()
{
Size = elementSize, Stride = stride, Data = data + element.Offset
});
}
else
{
throw new Exception($"Point Cloud {name} field has unsupported type {element.Type}");
}
}
}
throw new Exception($"Point Cloud does not have {name} field");
}
PointCloudData ImportPly(AssetImportContext context)
{
using (var file = MemoryMappedFile.CreateFromFile(context.assetPath, FileMode.Open))
{
long dataOffset;
long dataCount = 0;
int elementOffset = 0;
var properties = new List <string>();
var elements = new List <PointElement>();
using (var view = file.CreateViewStream(0, 4096, MemoryMappedFileAccess.Read))
{
var buffer = new byte[4096];
int length = view.Read(buffer, 0, buffer.Length);
using (var stream = new MemoryStream(buffer, 0, length, false))
{
var byteLine = new byte[128];
bool first = true;
while (true)
{
int byteCount = stream.Read(byteLine, 0, byteLine.Length);
int index = -1;
for (int i = 0; i < byteCount; i++)
{
if (byteLine[i] == '\n' || byteLine[i] == '\r')
{
index = i;
break;
}
}
if (index == -1)
{
throw new Exception("Bad PLY file");
}
var line = Encoding.ASCII.GetString(byteLine, 0, index);
byte next = byteLine[index + 1];
stream.Position -= byteLine.Length - (index + (next == '\r' || next == '\n' ? 2 : 1));
if (first && line != "ply")
{
throw new Exception("Bad PLY file format");
}
first = false;
if (line.StartsWith("format"))
{
var format = line.Split(new[] { ' ' });
if (format[1] != "binary_little_endian" || format[2] != "1.0")
{
throw new Exception($"Unsupported PLY format: {line}");
}
}
else if (line.StartsWith("property"))
{
var props = line.Split(new[] { ' ' }, 3);
if (props[1] != "list")
{
PointElementType?type = null;
PointElementName?name = null;
if (props[1] == "uint8")
{
type = PointElementType.Byte;
}
if (props[1] == "float32")
{
type = PointElementType.Float;
}
if (props[1] == "float64")
{
type = PointElementType.Double;
}
if (props[1] == "uchar")
{
type = PointElementType.Byte;
}
if (props[1] == "float")
{
type = PointElementType.Float;
}
if (props[1] == "double")
{
type = PointElementType.Double;
}
if (props[2] == "x")
{
name = PointElementName.X;
}
if (props[2] == "y")
{
name = PointElementName.Y;
}
if (props[2] == "z")
{
name = PointElementName.Z;
}
if (props[2] == "red")
{
name = PointElementName.R;
}
if (props[2] == "green")
{
name = PointElementName.G;
}
if (props[2] == "blue")
{
name = PointElementName.B;
}
if (props[2] == "intensity")
{
name = PointElementName.I;
}
if (props[2] == "scalar_intensity")
{
name = PointElementName.I;
}
if (!type.HasValue)
{
throw new Exception($"PLY file has unsupported property type {props[1]}");
}
if (name.HasValue)
{
elements.Add(new PointElement()
{
Type = type.Value, Name = name.Value, Offset = elementOffset
});
}
elementOffset += PointElement.GetSize(type.Value);
}
}
else if (line.StartsWith("element vertex"))
{
var vertex = line.Split(new[] { ' ' }, 3);
dataCount = long.Parse(vertex[2]);
}
else if (line.StartsWith("end_header"))
{
break;
}
}
dataOffset = stream.Position;
}
}
int dataStride = elementOffset;
using (var view = file.CreateViewAccessor(dataOffset, dataCount * dataStride, MemoryMappedFileAccess.Read))
{
return(ImportPoints(context, view, dataCount, dataStride, elements));
}
}
}
