66 lines
2.3 KiB
Python
66 lines
2.3 KiB
Python
import numpy as np
|
|
from stl import mesh
|
|
import struct
|
|
import sys
|
|
import os
|
|
|
|
def simplify_stl(input_path, output_path, keep_ratio=0.1):
|
|
try:
|
|
# Load mesh using numpy-stl
|
|
m = mesh.Mesh.from_file(input_path)
|
|
vertices = m.vectors.reshape(-1, 3)
|
|
|
|
min_v = vertices.min(axis=0)
|
|
max_v = vertices.max(axis=0)
|
|
bbox_size = max_v - min_v
|
|
max_dim = np.max(bbox_size)
|
|
|
|
if max_dim == 0:
|
|
m.save(output_path)
|
|
return True
|
|
|
|
# Target roughly a resolution that gives us keep_ratio faces.
|
|
# This is a heuristic approach to grid-based vertex clustering.
|
|
# We start with a baseline resolution (e.g. 2% of max dimension)
|
|
# and adjust if needed.
|
|
grid_resolution = max_dim * 0.02
|
|
|
|
# Function to simplify given a grid size
|
|
def do_simplify(g_size):
|
|
v_idx = np.round((vertices - min_v) / g_size).astype(np.int32)
|
|
# Find unique grid cells and map old vertices to them
|
|
_, unique_idx, inv_idx = np.unique(v_idx, axis=0, return_index=True, return_inverse=True)
|
|
new_verts = vertices[unique_idx]
|
|
|
|
# Map faces to new vertices
|
|
faces = inv_idx.reshape(-1, 3)
|
|
|
|
# Remove degenerate faces (faces where at least two vertices resolve to the same cell)
|
|
valid = (faces[:,0] != faces[:,1]) & (faces[:,1] != faces[:,2]) & (faces[:,0] != faces[:,2])
|
|
valid_faces = faces[valid]
|
|
|
|
return new_verts, valid_faces
|
|
|
|
new_vertices, valid_faces = do_simplify(grid_resolution)
|
|
|
|
# Build the simplified mesh
|
|
new_m = mesh.Mesh(np.zeros(valid_faces.shape[0], dtype=mesh.Mesh.dtype))
|
|
|
|
# Vectorized assignment
|
|
new_m.vectors[:, 0, :] = new_vertices[valid_faces[:, 0]]
|
|
new_m.vectors[:, 1, :] = new_vertices[valid_faces[:, 1]]
|
|
new_m.vectors[:, 2, :] = new_vertices[valid_faces[:, 2]]
|
|
|
|
# Calculate normals correctly
|
|
new_m.update_normals()
|
|
new_m.save(output_path)
|
|
return True
|
|
|
|
except Exception as e:
|
|
print(f"Error simplifying STL: {e}")
|
|
return False
|
|
|
|
if __name__ == "__main__":
|
|
if len(sys.argv) > 2:
|
|
simplify_stl(sys.argv[1], sys.argv[2])
|