import struct
from pathlib import Path
[docs]
def import_surface_from_obj(input_file: Path):
"""Import a triangulated surface from an OBJ file.
.. todo:: Implement the import_surface_from_obj function
Args:
input_file (Path): The input OBJ file path.
Returns:
dict: A dictionary with 'vertices' and 'faces'.
"""
vertices = []
faces = []
with open(input_file, 'r') as f:
for line in f:
parts = line.strip().split()
if not parts:
continue
if parts[0] == 'v': # Vertex
vertices.append(tuple(map(float, parts[1:4])))
elif parts[0] == 'f': # Face
faces.append(tuple(int(idx) - 1 for idx in parts[1:4])) # Convert to 0-based indexing
return {'vertices': vertices, 'faces': faces}
[docs]
def import_surface_from_ply_ascii(input_file: Path):
"""Import a triangulated surface from an ASCII PLY file.
.. todo:: Implement the import_surface_from_ply_ascii function
Args:
input_file (Path): The input PLY file path.
Returns:
dict: A dictionary with 'vertices' and 'faces'.
"""
vertices = []
faces = []
with open(input_file, 'r') as f:
header = True
for line in f:
if header:
if line.strip() == "end_header":
header = False
continue
parts = line.strip().split()
if len(parts) == 3: # Vertex
vertices.append(tuple(map(float, parts)))
elif len(parts) > 3 and parts[0] == '3': # Face
faces.append(tuple(map(int, parts[1:4])))
return {'vertices': vertices, 'faces': faces}
[docs]
def import_surface_from_ply_binary(input_file: Path):
"""Import a triangulated surface from a binary PLY file.
.. todo:: Implement the import_surface_from_ply_binary function
Args:
input_file (Path): The input PLY file path.
Returns:
dict: A dictionary with 'vertices' and 'faces'.
"""
vertices = []
faces = []
with open(input_file, 'rb') as f:
header = []
while True:
line = f.readline().decode().strip()
header.append(line)
if line == "end_header":
break
# Parse header to determine vertex and face counts
vertex_count = 0
face_count = 0
for line in header:
if line.startswith("element vertex"):
vertex_count = int(line.split()[-1])
elif line.startswith("element face"):
face_count = int(line.split()[-1])
# Read vertices
for _ in range(vertex_count):
vertex_data = f.read(12) # 3 floats (4 bytes each)
vertices.append(struct.unpack('fff', vertex_data))
# Read faces
for _ in range(face_count):
face_data = f.read(13) # 1 uchar + 3 ints (1 + 4*3 bytes)
_, v1, v2, v3 = struct.unpack('Biii', face_data)
faces.append((v1, v2, v3))
return {'vertices': vertices, 'faces': faces}