Files
reconstruction/superSMPL/IO.py
T
2022-12-22 22:33:56 +00:00

138 lines
4.7 KiB
Python
Executable File

import numpy as np
from struct import pack, unpack
"""
Reads PC2 files, and proposed format PC16 files
Inputs:
- file: path to .pc2/.pc16 file
- float16: False for PC2 files, True for PC16
Output:
- data: dictionary with .pc2/.pc16 file data
NOTE: 16-bit floats lose precision with high values (positive or negative),
we do not recommend using this format for data outside range [-2, 2]
"""
def readPC2(file, float16=False):
assert file.endswith('.pc2') and not float16 or file.endswith('.pc16') and float16, 'File format not consistent with specified input format'
data = {}
bytes = 2 if float16 else 4
dtype = np.float16 if float16 else np.float32
with open(file, 'rb') as f:
# Header
data['sign'] = f.read(12)
# data['version'] = int.from_bytes(f.read(4), 'little')
data['version'] = unpack('<i', f.read(4))[0]
# Num points
# data['nPoints'] = int.from_bytes(f.read(4), 'little')
data['nPoints'] = unpack('<i', f.read(4))[0]
# Start frame
data['startFrame'] = unpack('f', f.read(4))
# Sample rate
data['sampleRate'] = unpack('f', f.read(4))
# Number of samples
# data['nSamples'] = int.from_bytes(f.read(4), 'little')
data['nSamples'] = unpack('<i', f.read(4))[0]
# Animation data
size = data['nPoints']*data['nSamples']*3*bytes
data['V'] = np.frombuffer(f.read(size), dtype=dtype).astype(np.float32)
data['V'] = data['V'].reshape(data['nSamples'], data['nPoints'], 3)
return data
"""
Reads an specific frame of PC2/PC16 files
Inputs:
- file: path to .pc2/.pc16 file
- frame: number of the frame to read
- float16: False for PC2 files, True for PC16
Output:
- T: mesh vertex data at specified frame
"""
def readPC2Frame(file, frame, float16=False):
assert file.endswith('.pc2') and not float16 or file.endswith('.pc16') and float16, 'File format not consistent with specified input format'
assert frame >= 0 and isinstance(frame,int), 'Frame must be a positive integer'
bytes = 2 if float16 else 4
dtype = np.float16 if float16 else np.float32
with open(file,'rb') as f:
# Num points
f.seek(16)
# nPoints = int.from_bytes(f.read(4), 'little')
nPoints = unpack('<i', f.read(4))[0]
# Number of samples
f.seek(28)
# nSamples = int.from_bytes(f.read(4), 'little')
nSamples = unpack('<i', f.read(4))[0]
if frame > nSamples:
print("Frame index outside size")
print("\tN. frame: " + str(frame))
print("\tN. samples: " + str(nSamples))
return
# Read frame
size = nPoints * 3 * bytes
f.seek(size * frame, 1) # offset from current '1'
T = np.frombuffer(f.read(size), dtype=dtype).astype(np.float32)
return T.reshape(nPoints, 3)
"""
Writes PC2 and PC16 files
Inputs:
- file: path to file (overwrites if exists)
- V: 3D animation data as a three dimensional array (N. Frames x N. Vertices x 3)
- float16: False for writing as PC2 file, True for PC16
This function assumes 'startFrame' to be 0 and 'sampleRate' to be 1
NOTE: 16-bit floats lose precision with high values (positive or negative),
we do not recommend using this format for data outside range [-2, 2]
"""
def writePC2(file, V, float16=False):
assert file.endswith('.pc2') and not float16 or file.endswith('.pc16') and float16, 'File format not consistent with specified input format'
if float16: V = V.astype(np.float16)
else: V = V.astype(np.float32)
with open(file, 'wb') as f:
# Create the header
headerFormat='<12siiffi'
headerStr = pack(headerFormat, b'POINTCACHE2\0',
1, V.shape[1], 0, 1, V.shape[0])
f.write(headerStr)
# Write vertices
f.write(V.tobytes())
"""
Reads OBJ files
Only handles vertices, faces and UV maps
Input:
- file: path to .obj file
Outputs:
- V: 3D vertices
- F: 3D faces
- Vt: UV vertices
- Ft: UV faces
Correspondence between mesh and UV map is implicit in F to Ft correspondences
If no UV map data in .obj file, it shall return Vt=None and Ft=None
"""
def readOBJ(file):
V, Vt, F, Ft = [], [], [], []
with open(file, 'r') as f:
T = f.readlines()
for t in T:
# 3D vertex
if t.startswith('v '):
v = [float(n) for n in t.replace('v ','').split(' ')]
V += [v]
# UV vertex
elif t.startswith('vt '):
v = [float(n) for n in t.replace('vt ','').split(' ')]
Vt += [v]
# Face
elif t.startswith('f '):
idx = [n.split('/') for n in t.replace('f ','').split(' ')]
f = [int(n[0]) - 1 for n in idx]
F += [f]
# UV face
if '/' in t:
f = [int(n[1]) - 1 for n in idx]
Ft += [f]
V = np.array(V, np.float32)
Vt = np.array(Vt, np.float32)
if Ft: assert len(F) == len(Ft), 'Inconsistent .obj file, mesh and UV map do not have the same number of faces'
else: Vt, Ft = None, None
return V, F, Vt, Ft