854 lines
30 KiB
Python
854 lines
30 KiB
Python
import numpy as np
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from collections import deque, defaultdict
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try:
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# `pip install pillow`
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# optional: used for textured meshes
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import PIL.Image as Image
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except BaseException as E:
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# if someone tries to use Image re-raise
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# the import error so they can debug easily
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from ..exceptions import ExceptionModule
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Image = ExceptionModule(E)
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from .. import util
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from ..visual.color import to_float
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from ..visual.texture import unmerge_faces, TextureVisuals
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from ..visual.material import SimpleMaterial
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from ..constants import log, tol
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def load_obj(file_obj,
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resolver=None,
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split_object=False,
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group_material=True,
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**kwargs):
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"""
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Load a Wavefront OBJ file into kwargs for a trimesh.Scene
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object.
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Parameters
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--------------
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file_obj : file like object
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Contains OBJ data
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resolver : trimesh.visual.resolvers.Resolver
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Allow assets such as referenced textures and
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material files to be loaded
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split_object : bool
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Split meshes at each `o` declared in file
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group_material : bool
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Group faces that share the same material
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into the same mesh.
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Returns
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-------------
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kwargs : dict
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Keyword arguments which can be loaded by
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trimesh.exchange.load.load_kwargs into a trimesh.Scene
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"""
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# get text as bytes or string blob
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text = file_obj.read()
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# if text was bytes decode into string
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text = util.decode_text(text)
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# add leading and trailing newlines so we can use the
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# same logic even if they jump directly in to data lines
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text = '\n{}\n'.format(text.strip().replace('\r\n', '\n'))
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# Load Materials
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materials = {}
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mtl_position = text.find('mtllib')
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if mtl_position >= 0:
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# take the line of the material file after `mtllib`
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# which should be the file location of the .mtl file
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mtl_path = text[mtl_position + 6:text.find('\n', mtl_position)].strip()
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try:
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# use the resolver to get the data
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material_kwargs = parse_mtl(resolver[mtl_path],
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resolver=resolver)
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# turn parsed kwargs into material objects
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materials = {k: SimpleMaterial(**v)
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for k, v in material_kwargs.items()}
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except IOError:
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# usually the resolver couldn't find the asset
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log.warning('unable to load materials from: {}'.format(mtl_path))
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except BaseException:
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# something else happened so log a warning
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log.warning('unable to load materials from: {}'.format(mtl_path),
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exc_info=True)
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# extract vertices from raw text
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v, vn, vt, vc = _parse_vertices(text=text)
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# get relevant chunks that have face data
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# in the form of (material, object, chunk)
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face_tuples = _preprocess_faces(
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text=text, split_object=split_object)
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# combine chunks that have the same material
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# some meshes end up with a LOT of components
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# and will be much slower if you don't do this
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if group_material:
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face_tuples = _group_by_material(face_tuples)
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# Load Faces
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# now we have clean- ish faces grouped by material and object
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# so now we have to turn them into numpy arrays and kwargs
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# for trimesh mesh and scene objects
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geometry = {}
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while len(face_tuples) > 0:
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# consume the next chunk of text
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material, current_object, chunk = face_tuples.pop()
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# do wangling in string form
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# we need to only take the face line before a newline
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# using builtin functions in a list comprehension
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# is pretty fast relative to other options
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# this operation is the only one that is O(len(faces))
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# slower due to the tight-loop conditional:
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# face_lines = [i[:i.find('\n')]
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# for i in chunk.split('\nf ')[1:]
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# if i.rfind('\n') >0]
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# maxsplit=1 means that it can stop working
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# after it finds the first newline
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# passed as arg as it's not a kwarg in python2
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face_lines = [i.split('\n', 1)[0]
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for i in chunk.split('\nf ')[1:]]
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# then we are going to replace all slashes with spaces
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joined = ' '.join(face_lines).replace('/', ' ')
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# the fastest way to get to a numpy array
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# processes the whole string at once into a 1D array
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# also wavefront is 1-indexed (vs 0-indexed) so offset
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array = np.fromstring(joined, sep=' ', dtype=np.int64) - 1
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# get the number of raw 2D columns in a sample line
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columns = len(face_lines[0].strip().replace('/', ' ').split())
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# make sure we have the right number of values for vectorized
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if len(array) == (columns * len(face_lines)):
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# everything is a nice 2D array
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faces, faces_tex, faces_norm = _parse_faces_vectorized(
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array=array,
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columns=columns,
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sample_line=face_lines[0])
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else:
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# if we had something annoying like mixed in quads
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# or faces that differ per-line we have to loop
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# i.e. something like:
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# '31407 31406 31408',
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# '32303/2469 32304/2469 32305/2469',
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log.warning('faces have mixed data, using slow fallback!')
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faces, faces_tex, faces_norm = _parse_faces_fallback(face_lines)
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# TODO: name usually falls back to something useless
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name = current_object
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if name is None or len(name) == 0 or name in geometry:
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name = '{}_{}'.format(name, util.unique_id())
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# try to get usable texture
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mesh = kwargs.copy()
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if faces_tex is not None:
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# convert faces referencing vertices and
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# faces referencing vertex texture to new faces
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# where each face
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if faces_norm is not None and len(faces_norm) == len(faces):
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new_faces, mask_v, mask_vt, mask_vn = unmerge_faces(
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faces, faces_tex, faces_norm)
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else:
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mask_vn = None
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new_faces, mask_v, mask_vt = unmerge_faces(faces, faces_tex)
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if tol.strict:
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# we should NOT have messed up the faces
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# note: this is EXTREMELY slow due to all the
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# float comparisons so only run this in unit tests
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assert np.allclose(v[faces], v[mask_v][new_faces])
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# faces should all be in bounds of vertives
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assert new_faces.max() < len(v[mask_v])
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try:
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# survive index errors as sometimes we
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# want materials without UV coordinates
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uv = vt[mask_vt]
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except BaseException as E:
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uv = None
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raise E
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# mask vertices and use new faces
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mesh.update({'vertices': v[mask_v].copy(),
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'faces': new_faces})
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else:
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# otherwise just use unmasked vertices
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uv = None
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# check to make sure indexes are in bounds
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if tol.strict:
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assert faces.max() < len(v)
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if vn is not None and np.shape(faces_norm) == faces.shape:
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# do the crazy unmerging logic for split indices
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new_faces, mask_v, mask_vn = unmerge_faces(
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faces, faces_norm)
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else:
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# generate the mask so we only include
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# referenced vertices in every new mesh
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mask_v = np.zeros(len(v), dtype=np.bool)
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mask_v[faces] = True
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# reconstruct the faces with the new vertex indices
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inverse = np.zeros(len(v), dtype=np.int64)
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inverse[mask_v] = np.arange(mask_v.sum())
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new_faces = inverse[faces]
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# no normals
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mask_vn = None
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# start with vertices and faces
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mesh.update({'faces': new_faces,
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'vertices': v[mask_v].copy()})
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# if vertex colors are OK save them
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if vc is not None:
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mesh['vertex_colors'] = vc[mask_v]
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# if vertex normals are OK save them
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if mask_vn is not None:
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mesh['vertex_normals'] = vn[mask_vn]
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visual = None
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if material in materials:
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# use the material with the UV coordinates
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visual = TextureVisuals(
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uv=uv, material=materials[material])
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elif uv is not None and len(uv) == len(mesh['vertices']):
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# create a texture with an empty materials
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visual = TextureVisuals(uv=uv)
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elif material is not None:
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# case where material is specified but not available
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log.warning('specified material ({}) not loaded!'.format(
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material))
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# assign the visual
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mesh['visual'] = visual
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# store geometry by name
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geometry[name] = mesh
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if len(geometry) == 1:
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# TODO : should this be removed to always return a scene?
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return next(iter(geometry.values()))
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# add an identity transform for every geometry
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graph = [{'geometry': k, 'frame_to': k, 'matrix': np.eye(4)}
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for k in geometry.keys()]
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# convert to scene kwargs
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result = {'geometry': geometry,
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'graph': graph}
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return result
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def parse_mtl(mtl, resolver=None):
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"""
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Parse a loaded MTL file.
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Parameters
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-------------
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mtl : str or bytes
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Data from an MTL file
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resolver : trimesh.Resolver
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Fetch assets by name from file system, web, or other
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Returns
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------------
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mtllibs : list of dict
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Each dict has keys: newmtl, map_Kd, Kd
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"""
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# decode bytes into string if necessary
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mtl = util.decode_text(mtl)
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# current material
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material = None
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# materials referenced by name
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materials = {}
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# use universal newline splitting
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lines = str.splitlines(str(mtl).strip())
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# remap OBJ property names to kwargs for SimpleMaterial
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mapped = {'Kd': 'diffuse',
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'Ka': 'ambient',
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'Ks': 'specular',
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'Ns': 'glossiness'}
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for line in lines:
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# split by white space
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split = line.strip().split()
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# needs to be at least two values
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if len(split) <= 1:
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continue
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# the first value is the parameter name
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key = split[0]
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# start a new material
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if key == 'newmtl':
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# material name extracted from line like:
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# newmtl material_0
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if material is not None:
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# save the old material by old name and remove key
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materials[material.pop('newmtl')] = material
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# start a fresh new material
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material = {'newmtl': ' '.join(split[1:])}
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elif key == 'map_Kd':
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# represents the file name of the texture image
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try:
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file_data = resolver.get(split[1])
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# load the bytes into a PIL image
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# an image file name
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material['image'] = Image.open(
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util.wrap_as_stream(file_data))
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except BaseException:
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log.warning('failed to load image', exc_info=True)
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elif key in mapped.keys():
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try:
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# diffuse, ambient, and specular float RGB
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value = [float(x) for x in split[1:]]
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# if there is only one value return that
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if len(value) == 1:
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value = value[0]
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# store the key by mapped value
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material[mapped[key]] = value
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# also store key by OBJ name
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material[key] = value
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except BaseException:
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log.warning('failed to convert color!', exc_info=True)
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# pass everything as kwargs to material constructor
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elif material is not None:
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# save any other unspecified keys
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material[key] = split[1:]
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# reached EOF so save any existing materials
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if material:
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materials[material.pop('newmtl')] = material
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return materials
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def _parse_faces_vectorized(array, columns, sample_line):
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"""
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Parse loaded homogeneous (tri/quad) face data in a
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vectorized manner.
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Parameters
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------------
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array : (n,) int
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Indices in order
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columns : int
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Number of columns in the file
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sample_line : str
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A single line so we can assess the ordering
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Returns
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--------------
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faces : (n, d) int
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Faces in space
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faces_tex : (n, d) int or None
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Texture for each vertex in face
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faces_norm : (n, d) int or None
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Normal index for each vertex in face
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"""
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# reshape to columns
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array = array.reshape((-1, columns))
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# how many elements are in the first line of faces
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# i.e '13/1/13 14/1/14 2/1/2 1/2/1' is 4
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group_count = len(sample_line.strip().split())
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# how many elements are there for each vertex reference
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# i.e. '12/1/13' is 3
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per_ref = int(columns / group_count)
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# create an index mask we can use to slice vertex references
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index = np.arange(group_count) * per_ref
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# slice the faces out of the blob array
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faces = array[:, index]
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# TODO: probably need to support 8 and 12 columns for quads
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# or do something more general
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faces_tex, faces_norm = None, None
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if columns == 6:
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# if we have two values per vertex the second
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# one is index of texture coordinate (`vt`)
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# count how many delimiters are in the first face line
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# to see if our second value is texture or normals
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# do splitting to clip off leading/trailing slashes
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count = ''.join(i.strip('/') for i in sample_line.split()).count('/')
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if count == columns:
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# case where each face line looks like:
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# ' 75//139 76//141 77//141'
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# which is vertex/nothing/normal
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faces_norm = array[:, index + 1]
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elif count == int(columns / 2):
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# case where each face line looks like:
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# '75/139 76/141 77/141'
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# which is vertex/texture
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faces_tex = array[:, index + 1]
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else:
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log.warning('face lines are weird: {}'.format(
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sample_line))
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elif columns == 9:
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# if we have three values per vertex
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# second value is always texture
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faces_tex = array[:, index + 1]
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# third value is reference to vertex normal (`vn`)
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faces_norm = array[:, index + 2]
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return faces, faces_tex, faces_norm
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def _parse_faces_fallback(lines):
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"""
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Use a slow but more flexible looping method to process
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face lines as a fallback option to faster vectorized methods.
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Parameters
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-------------
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lines : (n,) str
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List of lines with face information
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Returns
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-------------
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faces : (m, 3) int
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Clean numpy array of face triangles
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"""
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# collect vertex, texture, and vertex normal indexes
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v, vt, vn = [], [], []
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# loop through every line starting with a face
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for line in lines:
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# remove leading newlines then
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# take first bit before newline then split by whitespace
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split = line.strip().split('\n')[0].split()
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# split into: ['76/558/76', '498/265/498', '456/267/456']
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len_split = len(split)
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if len_split == 3:
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pass
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elif len_split == 4:
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# triangulate quad face
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split = [split[0],
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split[1],
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split[2],
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split[2],
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split[3],
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split[0]]
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elif len_split > 4:
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# triangulate polygon, as a triangles fan
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r_split = []
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r_split_append = r_split.append
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for i in range(len(split) - 2):
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r_split_append(split[0])
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r_split_append(split[i + 1])
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r_split_append(split[i + 2])
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split = r_split
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else:
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log.warning(
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'face need at least 3 elements (got {})! skipping!'.format(
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len(split)))
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continue
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# f is like: '76/558/76'
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for f in split:
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# vertex, vertex texture, vertex normal
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split = f.split('/')
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# we always have a vertex reference
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v.append(int(split[0]))
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# faster to try/except than check in loop
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try:
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vt.append(int(split[1]))
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except BaseException:
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pass
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try:
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# vertex normal is the third index
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vn.append(int(split[2]))
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except BaseException:
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pass
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# shape into triangles and switch to 0-indexed
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faces = np.array(v, dtype=np.int64).reshape((-1, 3)) - 1
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faces_tex, normals = None, None
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if len(vt) == len(v):
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faces_tex = np.array(vt, dtype=np.int64).reshape((-1, 3)) - 1
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if len(vn) == len(v):
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normals = np.array(vn, dtype=np.int64).reshape((-1, 3)) - 1
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return faces, faces_tex, normals
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def _parse_vertices(text):
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"""
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Parse raw OBJ text into vertices, vertex normals,
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vertex colors, and vertex textures.
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Parameters
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-------------
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text : str
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Full text of an OBJ file
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Returns
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-------------
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v : (n, 3) float
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Vertices in space
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vn : (m, 3) float or None
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Vertex normals
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vt : (p, 2) float or None
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Vertex texture coordinates
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vc : (n, 3) float or None
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Per-vertex color
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"""
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# the first position of a vertex in the text blob
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# we only really need to search from the start of the file
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# up to the location of out our first vertex but we
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# are going to use this check for "do we have texture"
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# determination later so search the whole stupid file
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starts = {k: text.find('\n{} '.format(k)) for k in
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['v', 'vt', 'vn']}
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# no valid values so exit early
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if not any(v >= 0 for v in starts.values()):
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return None, None, None, None
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# find the last position of each valid value
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ends = {k: text.find(
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'\n', text.rfind('\n{} '.format(k)) + 2 + len(k))
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for k, v in starts.items() if v >= 0}
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# take the first and last position of any vertex property
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start = min(s for s in starts.values() if s >= 0)
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end = max(e for e in ends.values() if e >= 0)
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# get the chunk of test that contains vertex data
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chunk = text[start:end].replace('+e', 'e').replace('-e', 'e')
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# get the clean-ish data from the file as python lists
|
|
data = {k: [i.split('\n', 1)[0]
|
|
for i in chunk.split('\n{} '.format(k))[1:]]
|
|
for k, v in starts.items() if v >= 0}
|
|
|
|
# count the number of data values per row on a sample row
|
|
per_row = {k: len(v[0].split()) for k, v in data.items()}
|
|
|
|
# convert data values into numpy arrays
|
|
result = defaultdict(lambda: None)
|
|
for k, value in data.items():
|
|
# use joining and fromstring to get as numpy array
|
|
array = np.fromstring(
|
|
' '.join(value), sep=' ', dtype=np.float64)
|
|
# what should our shape be
|
|
shape = (len(value), per_row[k])
|
|
# check shape of flat data
|
|
if len(array) == np.product(shape):
|
|
# we have a nice 2D array
|
|
result[k] = array.reshape(shape)
|
|
else:
|
|
# try to recover with a slightly more expensive loop
|
|
count = per_row[k]
|
|
try:
|
|
# try to get result through reshaping
|
|
result[k] = np.fromstring(
|
|
' '.join(i.split()[:count] for i in value),
|
|
sep=' ', dtype=np.float64).reshape(shape)
|
|
except BaseException:
|
|
pass
|
|
|
|
# vertices
|
|
v = result['v']
|
|
# vertex colors are stored next to vertices
|
|
vc = None
|
|
if v is not None and v.shape[1] >= 6:
|
|
# vertex colors are stored after vertices
|
|
v, vc = v[:, :3], v[:, 3:6]
|
|
elif v is not None and v.shape[1] > 3:
|
|
# we got a lot of something unknowable
|
|
v = v[:, :3]
|
|
|
|
# vertex texture or None
|
|
vt = result['vt']
|
|
if vt is not None:
|
|
# sometimes UV coordinates come in as UVW
|
|
vt = vt[:, :2]
|
|
# vertex normals or None
|
|
vn = result['vn']
|
|
|
|
# check will generally only be run in unit tests
|
|
# so we are allowed to do things that are slow
|
|
if tol.strict:
|
|
# check to make sure our subsetting
|
|
# didn't miss any vertices or data
|
|
assert len(v) == text.count('\nv ')
|
|
# make sure optional data matches file too
|
|
if vn is not None:
|
|
assert len(vn) == text.count('\nvn ')
|
|
if vt is not None:
|
|
assert len(vt) == text.count('\nvt ')
|
|
|
|
return v, vn, vt, vc
|
|
|
|
|
|
def _group_by_material(face_tuples):
|
|
"""
|
|
For chunks of faces split by material group
|
|
the chunks that share the same material.
|
|
|
|
Parameters
|
|
------------
|
|
face_tuples : (n,) list of (material, obj, chunk)
|
|
The data containing faces
|
|
|
|
Returns
|
|
------------
|
|
grouped : (m,) list of (material, obj, chunk)
|
|
Grouped by material
|
|
"""
|
|
|
|
# store the chunks grouped by material
|
|
grouped = defaultdict(lambda: ['', '', []])
|
|
# loop through existring
|
|
for material, obj, chunk in face_tuples:
|
|
grouped[material][0] = material
|
|
grouped[material][1] = obj
|
|
# don't do a million string concatenations in loop
|
|
grouped[material][2].append(chunk)
|
|
# go back and do a join to make a single string
|
|
for k in grouped.keys():
|
|
grouped[k][2] = '\n'.join(grouped[k][2])
|
|
# return as list
|
|
return list(grouped.values())
|
|
|
|
|
|
def _preprocess_faces(text, split_object=False):
|
|
# Pre-Process Face Text
|
|
# Rather than looking at each line in a loop we're
|
|
# going to split lines by directives which indicate
|
|
# a new mesh, specifically 'usemtl' and 'o' keys
|
|
# search for materials, objects, faces, or groups
|
|
starters = ['\nusemtl ', '\no ', '\nf ', '\ng ', '\ns ']
|
|
f_start = len(text)
|
|
# first index of material, object, face, group, or smoother
|
|
for st in starters:
|
|
search = text.find(st, 0, f_start)
|
|
# if not contained find will return -1
|
|
if search < 0:
|
|
continue
|
|
# subtract the length of the key from the position
|
|
# to make sure it's included in the slice of text
|
|
if search < f_start:
|
|
f_start = search
|
|
# index in blob of the newline after the last face
|
|
f_end = text.find('\n', text.rfind('\nf ') + 3)
|
|
# get the chunk of the file that has face information
|
|
if f_end >= 0:
|
|
# clip to the newline after the last face
|
|
f_chunk = text[f_start:f_end]
|
|
else:
|
|
# no newline after last face
|
|
f_chunk = text[f_start:]
|
|
|
|
if tol.strict:
|
|
# check to make sure our subsetting didn't miss any faces
|
|
assert f_chunk.count('\nf ') == text.count('\nf ')
|
|
|
|
# start with undefined objects and material
|
|
current_object = None
|
|
current_material = None
|
|
# where we're going to store result tuples
|
|
# containing (material, object, face lines)
|
|
face_tuples = []
|
|
|
|
# two things cause new meshes to be created: objects and materials
|
|
# first divide faces into groups split by material and objects
|
|
# face chunks using different materials will be treated
|
|
# as different meshes
|
|
for m_chunk in f_chunk.split('\nusemtl '):
|
|
# if empty continue
|
|
if len(m_chunk) == 0:
|
|
continue
|
|
|
|
# find the first newline in the chunk
|
|
# everything before it will be the usemtl direction
|
|
new_line = m_chunk.find('\n')
|
|
# if the file contained no materials it will start with a newline
|
|
if new_line == 0:
|
|
current_material = None
|
|
else:
|
|
# remove internal double spaces because why wouldn't that be OK
|
|
current_material = ' '.join(m_chunk[:new_line].strip().split())
|
|
|
|
# material chunk contains multiple objects
|
|
if split_object:
|
|
o_split = m_chunk.split('\no ')
|
|
else:
|
|
o_split = [m_chunk]
|
|
if len(o_split) > 1:
|
|
for o_chunk in o_split:
|
|
# set the object label
|
|
current_object = o_chunk[:o_chunk.find('\n')].strip()
|
|
# find the first face in the chunk
|
|
f_idx = o_chunk.find('\nf ')
|
|
# if we have any faces append it to our search tuple
|
|
if f_idx >= 0:
|
|
face_tuples.append(
|
|
(current_material,
|
|
current_object,
|
|
o_chunk[f_idx:]))
|
|
else:
|
|
# if there are any faces in this chunk add them
|
|
f_idx = m_chunk.find('\nf ')
|
|
if f_idx >= 0:
|
|
face_tuples.append(
|
|
(current_material,
|
|
current_object,
|
|
m_chunk[f_idx:]))
|
|
return face_tuples
|
|
|
|
|
|
def export_obj(mesh,
|
|
include_normals=True,
|
|
include_color=True,
|
|
include_texture=True,
|
|
return_texture=False,
|
|
write_texture=True,
|
|
resolver=None,
|
|
digits=8):
|
|
"""
|
|
Export a mesh as a Wavefront OBJ file.
|
|
TODO: scenes with textured meshes
|
|
|
|
Parameters
|
|
-----------
|
|
mesh : trimesh.Trimesh
|
|
Mesh to be exported
|
|
include_normals : bool
|
|
Include vertex normals in export
|
|
include_color : bool
|
|
Include vertex color in export
|
|
include_texture bool
|
|
Include `vt` texture in file text
|
|
return_texture : bool
|
|
If True, return a dict with texture files
|
|
write_texture : bool
|
|
If True and a writable resolver is passed
|
|
write the referenced texture files with resolver
|
|
resolver : None or trimesh.resolvers.Resolver
|
|
Resolver which can write referenced text objects
|
|
digits : int
|
|
Number of digits to include for floating point
|
|
|
|
Returns
|
|
-----------
|
|
export : str
|
|
OBJ format output
|
|
texture : dict
|
|
[OPTIONAL]
|
|
Contains files that need to be saved in the same
|
|
directory as the exported mesh: {file name : bytes}
|
|
"""
|
|
# store the multiple options for formatting
|
|
# vertex indexes for faces
|
|
face_formats = {('v',): '{}',
|
|
('v', 'vn'): '{}//{}',
|
|
('v', 'vt'): '{}/{}',
|
|
('v', 'vn', 'vt'): '{}/{}/{}'}
|
|
|
|
# check the input
|
|
if util.is_instance_named(mesh, 'Trimesh'):
|
|
meshes = [mesh]
|
|
elif util.is_instance_named(mesh, 'Scene'):
|
|
meshes = mesh.dump()
|
|
else:
|
|
raise ValueError('must be Trimesh or Scene!')
|
|
|
|
objects = deque([])
|
|
|
|
counts = {'v': 0, 'vn': 0, 'vt': 0}
|
|
|
|
for mesh in meshes:
|
|
# we are going to reference face_formats with this
|
|
face_type = ['v']
|
|
# OBJ includes vertex color as RGB elements on the same line
|
|
if include_color and mesh.visual.kind in ['vertex', 'face']:
|
|
# create a stacked blob with position and color
|
|
v_blob = np.column_stack((
|
|
mesh.vertices,
|
|
to_float(mesh.visual.vertex_colors[:, :3])))
|
|
else:
|
|
# otherwise just export vertices
|
|
v_blob = mesh.vertices
|
|
|
|
# add the first vertex key and convert the array
|
|
# add the vertices
|
|
export = deque(
|
|
['v ' + util.array_to_string(
|
|
v_blob,
|
|
col_delim=' ',
|
|
row_delim='\nv ',
|
|
digits=digits)])
|
|
# only include vertex normals if they're already stored
|
|
if include_normals and 'vertex_normals' in mesh._cache.cache:
|
|
# if vertex normals are stored in cache export them
|
|
face_type.append('vn')
|
|
export.append('vn ' + util.array_to_string(
|
|
mesh.vertex_normals,
|
|
col_delim=' ',
|
|
row_delim='\nvn ',
|
|
digits=digits))
|
|
|
|
tex_data = None
|
|
if include_texture and hasattr(mesh.visual, 'uv'):
|
|
# if vertex texture exists and is the right shape
|
|
face_type.append('vt')
|
|
# add the uv coordinates
|
|
export.append('vt ' + util.array_to_string(
|
|
mesh.visual.uv,
|
|
col_delim=' ',
|
|
row_delim='\nvt ',
|
|
digits=digits))
|
|
(tex_data,
|
|
tex_name,
|
|
mtl_name) = mesh.visual.material.to_obj()
|
|
# add the reference to the MTL file
|
|
objects.appendleft('mtllib {}'.format(mtl_name))
|
|
# add the directive to use the exported material
|
|
export.appendleft('usemtl {}'.format(tex_name))
|
|
# the format for a single vertex reference of a face
|
|
face_format = face_formats[tuple(face_type)]
|
|
# add the exported faces to the export
|
|
export.append('f ' + util.array_to_string(
|
|
mesh.faces + 1 + counts['v'],
|
|
col_delim=' ',
|
|
row_delim='\nf ',
|
|
value_format=face_format))
|
|
# offset our vertex position
|
|
counts['v'] += len(mesh.vertices)
|
|
|
|
# add object name if found in metadata
|
|
if 'name' in mesh.metadata:
|
|
export.appendleft(
|
|
'\no {}'.format(mesh.metadata['name']))
|
|
# add this object
|
|
objects.append('\n'.join(export))
|
|
|
|
# add a created-with header to the top of the file
|
|
objects.appendleft('# https://github.com/mikedh/trimesh')
|
|
# combine elements into a single string
|
|
text = '\n'.join(objects)
|
|
|
|
# if we have a resolver and have asked to write texture
|
|
if write_texture and resolver is not None and tex_data is not None:
|
|
# not all resolvers have a write method
|
|
[resolver.write(k, v) for k, v in tex_data.items()]
|
|
|
|
# if we exported texture it changes returned values
|
|
if return_texture:
|
|
return text, tex_data
|
|
|
|
return text
|
|
|
|
|
|
_obj_loaders = {'obj': load_obj}
|