PLY is a standard format to store mesh data.
See the specification
ZARR is a data store format.
Write and read PLY files to a zarr store here is a basic ply file
ply
format ascii 1.0 { ascii/binary, format version number }
comment made by Greg Turk { comments keyword specified, like all lines }
comment this file is a cube
element vertex 8 { define "vertex" element, 8 of them in file }
property float x { vertex contains float "x" coordinate }
property float y { y coordinate is also a vertex property }
property float z { z coordinate, too }
element face 6 { there are 6 "face" elements in the file }
property list uchar int vertex_index { "vertex_indices" is a list of ints }
end_header { delimits the end of the header }
0 0 0 { start of vertex list }
0 0 1
0 1 1
0 1 0
1 0 0
1 0 1
1 1 1
1 1 0
4 0 1 2 3 { start of face list }
4 7 6 5 4
4 0 4 5 1
4 1 5 6 2
4 2 6 7 3
4 3 7 4 0
The header is translated to a zarr group attrs object (JSON like)
ply_header = {
"format": "ascii 1.0",
"comments": [f"created by ply_zarr v0.0.1, {datetime.now().isoformat()}",],
"elements": {
"vertex": {
"size": 47,
"properties": [
("double", "x"),
("double", "y"),
("double", "z")
]
},
"face": {
"size": 105,
"properties": [
("list", "uint8", "int32", "vertex_indices"),
]
}
}
}The array heirarchy of the created zarr group is as follows:
group
├── 4
│ └── vertex_indices (6, 4) int32
└── points
├── color (8,) float64
├── x (8,) int64
├── y (8,) int64
└── z (8,) int64
ply-zarr relies on meshio and
uses a meshio.Mesh object as input to write a zarr group.
from ply_zarr import write
mesh = meshio.read("data/test.ply")
root = zarr.group()
write(root, mesh)pytest tests-
Due to a bug, exporting in other formats for non-triangular meshes will not work in general
-
Type hints & mypy everything
-
Strictier handeling of data formats
-
xarray compatibility (if possible?)