init

2026-02-12 23:22:11 +08:00
parent 7b09eb3d89
commit 89660bba4e
5988 changed files with 2517516 additions and 0 deletions
@@ -0,0 +1,98 @@
+import re
+
+import numpy as np
+
+from ..geometry import triangulate_quads
+from ..util import array_to_string, comment_strip, decode_text
+
+
+def load_off(file_obj, **kwargs) -> dict:
+    """
+    Load an OFF file into the kwargs for a Trimesh constructor.
+
+    Parameters
+    ----------
+    file_obj : file object
+      Contains an OFF file
+
+    Returns
+    ----------
+    loaded : dict
+      kwargs for Trimesh constructor
+    """
+    text = file_obj.read()
+    # will magically survive weird encoding sometimes
+    # comment strip will handle all cases of commenting
+    text = comment_strip(decode_text(text)).strip()
+
+    # split the first key
+    _, header, raw = re.split("(COFF|OFF)", text, maxsplit=1)
+    if header.upper() not in ["OFF", "COFF"]:
+        raise NameError(f"Not an OFF file! Header was: `{header}`")
+
+    # split into lines and remove whitespace
+    splits = [i.strip() for i in str.splitlines(str(raw))]
+    # remove empty lines
+    splits = [i for i in splits if len(i) > 0]
+
+    # the first non-comment line should be the counts
+    header = np.array(splits[0].split(), dtype=np.int64)
+    vertex_count, face_count = header[:2]
+
+    vertices = np.array(
+        [i.split()[:3] for i in splits[1 : vertex_count + 1]], dtype=np.float64
+    )
+
+    # will fail if incorrect number of vertices loaded
+    vertices = vertices.reshape((vertex_count, 3))
+
+    # get lines with face data
+    faces = [i.split() for i in splits[vertex_count + 1 : vertex_count + face_count + 1]]
+    # the first value is count
+    faces = [line[1 : int(line[0]) + 1] for line in faces]
+
+    faces = triangulate_quads(faces)
+    # save data as kwargs for a trimesh.Trimesh
+    kwargs = {"vertices": vertices, "faces": faces}
+
+    return kwargs
+
+
+def export_off(mesh, digits=10) -> str:
+    """
+    Export a mesh as an OFF file, a simple text format
+
+    Parameters
+    -----------
+    mesh : trimesh.Trimesh
+      Geometry to export
+    digits : int
+      Number of digits to include on floats
+
+    Returns
+    -----------
+    export : str
+      OFF format output
+    """
+    # make sure specified digits is an int
+    digits = int(digits)
+    # prepend a 3 (face count) to each face
+    faces_stacked = np.column_stack((np.ones(len(mesh.faces)) * 3, mesh.faces)).astype(
+        np.int64
+    )
+    # the header is vertex count, face count, another number
+    export = "\n".join(
+        [
+            "OFF",
+            str(len(mesh.vertices)) + " " + str(len(mesh.faces)) + " 0",
+            array_to_string(mesh.vertices, col_delim=" ", row_delim="\n", digits=digits),
+            array_to_string(faces_stacked, col_delim=" ", row_delim="\n"),
+            "",
+        ]
+    )
+
+    return export
+
+
+_off_loaders = {"off": load_off}
+_off_exporters = {"off": export_off}