space-game001/convert_model_to_binary.py
2026-05-01 21:47:54 +03:00

143 lines
4.2 KiB
Python

#!/usr/bin/env python3
"""
Convert a text-based static mesh file (.txt) to binary format (.txt.bin).
Usage:
python convert_model_to_binary.py <input.txt> [<output.bin>]
If the output path is not given it is derived by appending ".bin" to the input path,
e.g. resources/w/firebox.txt -> resources/w/firebox.txt.bin
Binary format (BSMF v1) -- all values little-endian:
HEADER
4 bytes magic "BSMF"
uint32 version (1)
uint32 numVertices
uint32 numTriangles
VERTICES (numVertices entries):
3 x float position x, y, z -- engine coordinate space
3 x float normal x, y, z -- engine coordinate space
2 x float UV u, v
TRIANGLES (numTriangles entries):
3 x uint32 vertex indices i0, i1, i2
The same Blender->engine axis swap applied by LoadFromTextFile02 is baked in here,
so the C++ binary loader can read coordinates directly without any post-processing:
engine_x = blender_y
engine_y = blender_z
engine_z = blender_x
"""
import struct
import re
import sys
import os
def _parse_floats(text):
return [float(x) for x in re.findall(r'[-+]?\d*\.?\d+(?:[eE][-+]?\d+)?', text)]
def _parse_ints(text):
return [int(x) for x in re.findall(r'[-]?\d+', text)]
def _swap_axes(x, y, z):
"""Blender Y-up -> engine coordinate system (mirrors LoadFromTextFile02)."""
return y, z, x
def convert(input_path, output_path):
with open(input_path, 'r', encoding='utf-8') as f:
lines = [line.rstrip('\n') for line in f]
idx = 0
def next_line():
nonlocal idx
while idx < len(lines):
line = lines[idx]
idx += 1
return line
raise EOFError("Unexpected end of file while parsing: " + input_path)
# --- Vertices ---
while True:
line = next_line()
if '===Vertices' in line:
break
m = re.search(r'\d+', line)
if not m:
raise ValueError("Could not parse vertex count from: " + line)
num_vertices = int(m.group())
positions = []
normals = []
uvs = []
for i in range(num_vertices):
line = next_line()
# V N: Pos(x, y, z) Norm(nx, ny, nz) UV(u, v)
nums = _parse_floats(line)
# nums[0] = vertex index (float-parsed), then 3 pos, 3 norm, 2 uv
if len(nums) < 9:
raise ValueError(f"Malformed vertex line {i}: {line}")
px, py, pz = _swap_axes(nums[1], nums[2], nums[3])
nx, ny, nz = _swap_axes(nums[4], nums[5], nums[6])
positions.append((px, py, pz))
normals.append((nx, ny, nz))
uvs.append((nums[7], nums[8]))
# --- Triangles ---
while True:
line = next_line()
if '===Triangles' in line:
break
m = re.search(r'\d+', line)
if not m:
raise ValueError("Could not parse triangle count from: " + line)
num_triangles = int(m.group())
triangles = []
for i in range(num_triangles):
line = next_line()
ints = _parse_ints(line)
if len(ints) != 3:
raise ValueError(f"Malformed triangle line {i}: {line}")
triangles.append(tuple(ints))
# --- Write binary ---
with open(output_path, 'wb') as out:
out.write(b'BSMF')
out.write(struct.pack('<I', 1))
out.write(struct.pack('<I', num_vertices))
out.write(struct.pack('<I', num_triangles))
for i in range(num_vertices):
out.write(struct.pack('<3f', *positions[i]))
out.write(struct.pack('<3f', *normals[i]))
out.write(struct.pack('<2f', *uvs[i]))
for tri in triangles:
out.write(struct.pack('<3I', *tri))
in_size = os.path.getsize(input_path)
out_size = os.path.getsize(output_path)
print(f"Converted: {input_path} ({in_size:,} bytes text) -> {output_path} ({out_size:,} bytes binary)")
print(f" Vertices: {num_vertices}, Triangles: {num_triangles}")
if __name__ == '__main__':
if len(sys.argv) < 2 or len(sys.argv) > 3:
print(f"Usage: {sys.argv[0]} <input.txt> [<output.bin>]")
sys.exit(1)
input_path = sys.argv[1]
output_path = sys.argv[2] if len(sys.argv) == 3 else input_path + '.bin'
convert(input_path, output_path)