class ObjParser(Parser):
"""This parser parses lines from .obj files."""
material_parser_cls = MaterialParser
cache_loader_cls = CacheLoader
cache_writer_cls = CacheWriter
def __init__(self, wavefront, file_name, strict=False, encoding="utf-8",
create_materials=False, collect_faces=False, parse=True, cache=False):
"""
Create a new obj parser
:param wavefront: The wavefront object
:param file_name: file name and path of obj file to read
:param strict: Enable strict mode
:param encoding: Encoding to read the text files
:param create_materials: Create materials if they don't exist
:param cache: Cache the loaded obj files in binary format
:param parse: Should parse be called immediately or manually called later?
"""
super(ObjParser, self).__init__(file_name, strict=strict, encoding=encoding)
self.wavefront = wavefront
self.mesh = None
self.material = None
self.create_materials = create_materials
self.collect_faces = collect_faces
self.cache = cache
self.cache_loaded = None
# Stores normals and texcoords for the entire file
self.normals = []
self.tex_coords = []
if parse:
self.parse()
def parse(self):
"""Trigger cache load or call superclass parse()"""
start = time.time()
if self.cache:
self.load_cache()
if not self.cache_loaded:
super(ObjParser, self).parse()
logger.info("%s: Load time: %s", self.file_name, time.time() - start)
def load_cache(self):
"""Loads the file using cached data"""
self.cache_loaded = self.cache_loader_cls(
self.file_name,
self.wavefront,
strict=self.strict,
create_materials=self.create_materials,
encoding=self.encoding,
parse=self.parse,
).parse()
def post_parse(self):
"""Called after parsing is done"""
if self.cache and not self.cache_loaded:
self.cache_writer_cls(self.file_name, self.wavefront).write()
# methods for parsing types of wavefront lines
def parse_v(self):
self.wavefront.vertices += list(self.consume_vertices())
def consume_vertices(self):
"""
Consumes all consecutive vertices.
NOTE: There is no guarantee this will consume all vertices since other
statements can also occur in the vertex list
"""
while True:
# Vertex color
if len(self.values) == 7:
yield (
float(self.values[1]),
float(self.values[2]),
float(self.values[3]),
float(self.values[4]),
float(self.values[5]),
float(self.values[6]),
)
# Positions only
else:
yield (
float(self.values[1]),
float(self.values[2]),
float(self.values[3]),
)
try:
self.next_line()
except StopIteration:
break
if not self.values:
break
if self.values[0] != "v":
break
def parse_vn(self):
self.normals += list(self.consume_normals())
# Since list() also consumes StopIteration we need to sanity check the line
# to make sure the parser advances
if self.values and self.values[0] == "vn":
self.next_line()
def consume_normals(self):
"""Consumes all consecutive texture coordinate lines"""
# The first iteration processes the current/first vn statement.
# The loop continues until there are no more vn-statements or StopIteration is raised by generator
while True:
yield (
float(self.values[1]),
float(self.values[2]),
float(self.values[3]),
)
try:
self.next_line()
except StopIteration:
break
if not self.values:
break
if self.values[0] != "vn":
break
def parse_vt(self):
self.tex_coords += list(self.consume_texture_coordinates())
# Since list() also consumes StopIteration we need to sanity check the line
# to make sure the parser advances
if self.values and self.values[0] == "vt":
self.next_line()
def consume_texture_coordinates(self):
"""Consume all consecutive texture coordinates"""
# The first iteration processes the current/first vt statement.
# The loop continues until there are no more vt-statements or StopIteration is raised by generator
while True:
yield (
float(self.values[1]),
float(self.values[2]),
)
try:
self.next_line()
except StopIteration:
break
if not self.values:
break
if self.values[0] != "vt":
break
@auto_consume
def parse_mtllib(self):
mtllib = " ".join(self.values[1:])
try:
materials = self.material_parser_cls(
os.path.join(self.dir, mtllib),
encoding=self.encoding,
strict=self.strict,
collect_faces=self.collect_faces
).materials
self.wavefront.mtllibs.append(mtllib)
except IOError:
if self.create_materials:
return
raise
for name, material in materials.items():
self.wavefront.materials[name] = material
@auto_consume
def parse_usemtl(self):
name = " ".join(self.values[1:])
self.material = self.wavefront.materials.get(name, None)
if self.material is None:
if not self.create_materials:
raise PywavefrontException('Unknown material: %s' % name)
# Create a new default material if configured to resolve missing ones
self.material = Material(name, is_default=True, has_faces=self.collect_faces)
self.wavefront.materials[name] = self.material
if self.mesh is not None:
self.mesh.add_material(self.material)
def parse_usemat(self):
self.parse_usemtl()
@auto_consume
def parse_o(self):
self.mesh = Mesh(self.values[1], has_faces=self.collect_faces)
self.wavefront.add_mesh(self.mesh)
def parse_f(self):
# Add default material if not created
if self.material is None:
self.material = Material(
"default{}".format(len(self.wavefront.materials)),
is_default=True,
has_faces=self.collect_faces
)
self.wavefront.materials[self.material.name] = self.material
# Support objects without `o` statement
if self.mesh is None:
self.mesh = Mesh(has_faces=self.collect_faces)
self.wavefront.add_mesh(self.mesh)
self.mesh.add_material(self.material)
self.mesh.add_material(self.material)
collected_faces = []
consumed_vertices = self.consume_faces(collected_faces if self.collect_faces else None)
self.material.vertices += list(consumed_vertices)
if self.collect_faces:
self.mesh.faces += list(collected_faces)
# Since list() also consumes StopIteration we need to sanity check the line
# to make sure the parser advances
if self.values and self.values[0] == "f":
self.next_line()
def consume_faces(self, collected_faces = None):
"""
Consume all consecutive faces
If more than three vertices are specified, we triangulate by the following procedure:
Let the face have n vertices in the order v_1 v_2 v_3 ... v_n, n >= 3.
We emit the first face as usual: (v_1, v_2, v_3). For each remaining vertex v_j,
j > 3, we emit (v_j, v_1, v_{j - 1}), e.g. (v_4, v_1, v_3), (v_5, v_1, v_4).
In a perfect world we could consume all vertices straight forward and draw using
GL_TRIANGLE_FAN (which exactly matches the procedure above).
This is however rarely the case.
* If the face is co-planar but concave, then you need to triangulate the face.
* If the face is not-coplanar, you are screwed, because OBJ doesn't preserve enough information
to know what tessellation was intended.
We always triangulate to make it simple.
:param collected_faces: A list into which all (possibly triangulated) faces will be written in the form
of triples of the corresponding absolute vertex IDs. These IDs index the list
self.wavefront.vertices.
Specify None to prevent consuming faces (and thus saving memory usage).
"""
# Helper tuple and function
Vertex = namedtuple('Vertex', 'idx pos color uv normal')
def emit_vertex(vertex):
# Just yield all the values except for the index
for v in vertex.uv:
yield v
for v in vertex.color:
yield v
for v in vertex.normal:
yield v
for v in vertex.pos:
yield v
# Figure out the format of the first vertex
# We raise an exception if any following vertex has a different format
# NOTE: Order is always v/vt/vn where v is mandatory and vt and vn is optional
has_vt = False
has_vn = False
has_colors = False
parts = self.values[1].split('/')
# We assume texture coordinates are present
if len(parts) == 2:
has_vt = True
# We have a vn, but not necessarily a vt
elif len(parts) == 3:
# Check for empty vt "1//1"
if parts[1] != '':
has_vt = True
has_vn = True
# Are we referencing vertex with color info?
vindex = int(parts[0])
if vindex < 0:
vindex += len(self.wavefront.vertices)
else:
vindex -= 1
vertex = self.wavefront.vertices[vindex]
has_colors = len(vertex) == 6
# Prepare vertex format string
vertex_format = "_".join(e[0] for e in [
("T2F", has_vt),
("C3F", has_colors),
("N3F", has_vn),
("V3F", True)
] if e[1])
# If the material already have vertex data, ensure the same format is used
if self.material.vertex_format and self.material.vertex_format != vertex_format:
raise ValueError((
"Trying to merge vertex data with different format: {}. "
"Material {} has vertex format {}"
).format(vertex_format, self.material.name, self.material.vertex_format))
self.material.vertex_format = vertex_format
# The first iteration processes the current/first f statement.
# The loop continues until there are no more f-statements or StopIteration is raised by generator
while True:
# The very first vertex, the last encountered and the current one
v1, vlast, vcurrent = None, None, None
for i, v in enumerate(self.values[1:]):
parts = v.split('/')
v_index = (int(parts[0]) - 1)
t_index = (int(parts[1]) - 1) if has_vt else None
n_index = (int(parts[2]) - 1) if has_vn else None
# Resolve negative index lookups
if v_index < 0:
v_index += len(self.wavefront.vertices) + 1
if has_vt and t_index < 0:
t_index += len(self.tex_coords) + 1
if has_vn and n_index < 0:
n_index += len(self.normals) + 1
vlast = vcurrent
vcurrent = Vertex(
idx = v_index,
pos = self.wavefront.vertices[v_index][0:3] if has_colors else self.wavefront.vertices[v_index],
color = self.wavefront.vertices[v_index][3:] if has_colors else (),
uv = self.tex_coords[t_index] if has_vt and t_index < len(self.tex_coords) else (),
normal = self.normals[n_index] if has_vn and n_index < len(self.normals) else ()
)
yield from emit_vertex(vcurrent)
# Triangulation when more than 3 elements are present
if i >= 3:
# The current vertex has already been emitted.
# Now just emit the first and the third vertices from the face
yield from emit_vertex(v1)
yield from emit_vertex(vlast)
if i == 0:
# Store the first vertex
v1 = vcurrent
if (collected_faces is not None) and (i >= 2):
if i == 2:
# Append the first triangle face in usual order (i.e. as specified in the Wavefront file)
collected_faces.append([v1.idx, vlast.idx, vcurrent.idx])
if i >= 3:
# Triangulate the remaining part of the face by putting the current, the first
# and the last parsed vertex in that order as a new face.
# This order coincides deliberately with the order from vertex yielding above.
collected_faces.append([vcurrent.idx, v1.idx, vlast.idx])
# Break out of the loop when there are no more f statements
try:
self.next_line()
except StopIteration:
break
if not self.values:
break
if self.values[0] != "f":
break
class ObjParser(Parser):
"""This parser parses lines from .obj files."""
def __init__(self,
wavefront,
file_name,
strict=False,
encoding="utf-8",
parse=True):
"""
Create a new obj parser
:param wavefront: The wavefront object
:param file_name: file name and path of obj file to read
:param strict: Enable strict mode
:param encoding: Encoding to read the text files
:param parse: Should parse be called immediately or manually called later?
"""
super(ObjParser, self).__init__(file_name,
strict=strict,
encoding=encoding)
self.wavefront = wavefront
self.mesh = None
self.material = None
self.vertices = [[0., 0., 0.]]
self.normals = [[0., 0., 0.]]
self.tex_coords = [[0., 0.]]
if parse:
self.parse()
# methods for parsing types of wavefront lines
def parse_v(self):
self.vertices += list(self.consume_vertices())
def consume_vertices(self):
"""
Consumes all consecutive vertices.
NOTE: There is no guarantee this will consume all vertices since other
statements can also occur in the vertex list
"""
while True:
# TODO: Check for vertex color
yield (
float(self.values[1]),
float(self.values[2]),
float(self.values[3]),
)
self.next_line()
if self.values[0] != "v":
break
def parse_vn(self):
self.normals += list(self.consume_normals())
# Since list() also consumes StopIteration we need to sanity check the line
# to make sure the parser advances
if self.values[0] == "vn":
self.next_line()
def consume_normals(self):
"""Consumes all consecutive texture coordinate lines"""
# The first iteration processes the current/first vn statement.
# The loop continues until there are no more vn-statements or StopIteration is raised by generator
while True:
yield (
float(self.values[1]),
float(self.values[2]),
float(self.values[3]),
)
self.next_line()
if self.values[0] != "vn":
break
def parse_vt(self):
self.tex_coords += list(self.consume_texture_coordinates())
# Since list() also consumes StopIteration we need to sanity check the line
# to make sure the parser advances
if self.values[0] == "vt":
self.next_line()
def consume_texture_coordinates(self):
"""Consume all consecutive texture coordinates"""
# The first iteration processes the current/first vt statement.
# The loop continues until there are no more vt-statements or StopIteration is raised by generator
while True:
yield (
float(self.values[1]),
float(self.values[2]),
)
self.next_line()
if self.values[0] != "vt":
break
@auto_consume
def parse_mtllib(self):
mtllib = os.path.join(self.dir, " ".join(self.values[1:]))
materials = MaterialParser(mtllib,
encoding=self.encoding,
strict=self.strict).materials
for material_name, material_object in materials.items():
self.wavefront.materials[material_name] = material_object
@auto_consume
def parse_usemtl(self):
self.material = self.wavefront.materials.get(self.values[1], None)
if self.material is None:
raise PywavefrontException('Unknown material: %s' % self.values[1])
if self.mesh is not None:
self.mesh.add_material(self.material)
def parse_usemat(self):
self.parse_usemtl()
@auto_consume
def parse_o(self):
self.mesh = Mesh(self.values[1])
self.wavefront.add_mesh(self.mesh)
def parse_f(self):
# Support objects without `o` statement
if self.mesh is None:
self.mesh = Mesh()
self.wavefront.add_mesh(self.mesh)
# Add default material if not created
if self.material is None:
self.material = Material(is_default=True)
self.wavefront.materials[self.material.name] = self.material
self.mesh.add_material(self.material)
self.material.vertices += list(self.consume_faces())
# Since list() also consumes StopIteration we need to sanity check the line
# to make sure the parser advances
if self.values[0] == "f":
self.next_line()
def consume_faces(self):
"""
Consume all consecutive faces
If a 4th vertex is specified, we triangulate.
In a perfect world we could consume this straight forward and draw using GL_TRIANGLE_FAN.
This is however rarely the case..
* If the face is co-planar but concave, then you need to triangulate the face
* If the face is not-coplanar, you are screwed, because OBJ doesn't preserve enough information
to know what tessellation was intended
We always triangulate to make it simple
"""
# The first iteration processes the current/first f statement.
# The loop continues until there are no more f-statements or StopIteration is raised by generator
while True:
v1 = None
vlast = None
for i, v in enumerate(self.values[1:]):
v_index, t_index, n_index = (
list(map(int, [j or 0
for j in v.split('/')])) + [0, 0])[:3]
# Resolve negative index lookups
if v_index < 0:
v_index += len(self.vertices) - 1
if t_index < 0:
t_index += len(self.tex_coords) - 1
if n_index < 0:
n_index += len(self.normals) - 1
vertex = (
self.tex_coords[t_index][0],
self.tex_coords[t_index][1],
self.normals[n_index][0],
self.normals[n_index][1],
self.normals[n_index][2],
self.vertices[v_index][0],
self.vertices[v_index][1],
self.vertices[v_index][2],
)
for v in vertex:
yield v
if i >= 3:
# Emit vertex 1 and 3 triangulating when a 4th vertex is specified
for v in v1:
yield v
for v in vlast:
yield v
if i == 0:
v1 = vertex
vlast = vertex
# Break out of the loop when there are no more f statements
self.next_line()
if self.values[0] != "f":
break
class ObjParser(Parser):
"""This parser parses lines from .obj files."""
material_parser_cls = MaterialParser
cache_loader_cls = CacheLoader
cache_writer_cls = CacheWriter
def __init__(self, wavefront, file_name, strict=False, encoding="utf-8",
create_materials=False, collect_faces=False, parse=True, cache=False,
warn_material=True):
"""
Create a new obj parser
:param wavefront: The wavefront object
:param file_name: file name and path of obj file to read
:param strict: Enable strict mode
:param encoding: Encoding to read the text files
:param create_materials: Create materials if they don't exist
:param cache: Cache the loaded obj files in binary format
:param parse: Should parse be called immediately or manually called later?
"""
super(ObjParser, self).__init__(file_name, strict=strict, encoding=encoding)
self.wavefront = wavefront
self.mesh = None
self.material = None
self.create_materials = create_materials
self.collect_faces = collect_faces
self.cache = cache
self.cache_loaded = None
self.warn_material = warn_material
# Stores normals and texcoords for the entire file
self.normals = []
self.tex_coords = []
if parse:
self.parse()
def parse(self):
"""Trigger cache load or call superclass parse()"""
start = time.time()
if self.cache:
self.load_cache()
if not self.cache_loaded:
super(ObjParser, self).parse()
logger.info("%s: Load time: %s", self.file_name, time.time() - start)
def load_cache(self):
"""Loads the file using cached data"""
self.cache_loaded = self.cache_loader_cls(
self.file_name,
self.wavefront,
strict=self.strict,
create_materials=self.create_materials,
encoding=self.encoding,
parse=self.parse,
).parse()
def post_parse(self):
"""Called after parsing is done"""
if self.cache and not self.cache_loaded:
self.cache_writer_cls(self.file_name, self.wavefront).write()
# methods for parsing types of wavefront lines
def parse_v(self):
self.wavefront.vertices += list(self.consume_vertices())
def consume_vertices(self):
"""
Consumes all consecutive vertices.
NOTE: There is no guarantee this will consume all vertices since other
statements can also occur in the vertex list
"""
while True:
# Vertex color
if len(self.values) == 7:
yield (
float(self.values[1]),
float(self.values[2]),
float(self.values[3]),
float(self.values[4]),
float(self.values[5]),
float(self.values[6]),
)
# Positions only
else:
yield (
float(self.values[1]),
float(self.values[2]),
float(self.values[3]),
)
try:
self.next_line()
except StopIteration:
break
if not self.values:
break
if self.values[0] != "v":
break
def parse_vn(self):
self.normals += list(self.consume_normals())
# Since list() also consumes StopIteration we need to sanity check the line
# to make sure the parser advances
if self.values and self.values[0] == "vn":
self.next_line()
def consume_normals(self):
"""Consumes all consecutive texture coordinate lines"""
# The first iteration processes the current/first vn statement.
# The loop continues until there are no more vn-statements or StopIteration is raised by generator
while True:
yield (
float(self.values[1]),
float(self.values[2]),
float(self.values[3]),
)
try:
self.next_line()
except StopIteration:
break
if not self.values:
break
if self.values[0] != "vn":
break
def parse_vt(self):
self.tex_coords += list(self.consume_texture_coordinates())
# Since list() also consumes StopIteration we need to sanity check the line
# to make sure the parser advances
if self.values and self.values[0] == "vt":
self.next_line()
def consume_texture_coordinates(self):
"""Consume all consecutive texture coordinates"""
# The first iteration processes the current/first vt statement.
# The loop continues until there are no more vt-statements or StopIteration is raised by generator
while True:
yield (
float(self.values[1]),
float(self.values[2]),
)
try:
self.next_line()
except StopIteration:
break
if not self.values:
break
if self.values[0] != "vt":
break
@auto_consume
def parse_mtllib(self):
mtllib = " ".join(self.values[1:])
try:
materials = self.material_parser_cls(
self.dir / mtllib,
encoding=self.encoding,
strict=self.strict,
collect_faces=self.collect_faces
).materials
self.wavefront.mtllibs.append(mtllib)
except IOError:
if self.create_materials:
return
raise
for name, material in materials.items():
self.wavefront.materials[name] = material
@auto_consume
def parse_usemtl(self):
name = " ".join(self.values[1:])
self.material = self.wavefront.materials.get(name, None)
if self.material is None:
if not self.create_materials:
raise PywavefrontException('Unknown material: %s' % name)
# Create a new default material if configured to resolve missing ones
self.material = Material(name, is_default=True, has_faces=self.collect_faces)
self.wavefront.materials[name] = self.material
if self.mesh is not None:
self.mesh.add_material(self.material)
def parse_usemat(self):
self.parse_usemtl()
@auto_consume
def parse_o(self):
self.mesh = Mesh(self.values[1], has_faces=self.collect_faces)
self.wavefront.add_mesh(self.mesh)
def parse_f(self):
# Add default material if not created
if self.material is None:
self.material = Material(
"default{}".format(len(self.wavefront.materials)),
is_default=True,
has_faces=self.collect_faces
)
self.wavefront.materials[self.material.name] = self.material
# Support objects without `o` statement
if self.mesh is None:
self.mesh = Mesh(has_faces=self.collect_faces)
self.wavefront.add_mesh(self.mesh)
self.mesh.add_material(self.material)
self.mesh.add_material(self.material)
collected_faces = []
consumed_vertices = self.consume_faces(collected_faces if self.collect_faces else None)
self.material.vertices += list(consumed_vertices)
if self.collect_faces:
self.mesh.faces += list(collected_faces)
# Since list() also consumes StopIteration we need to sanity check the line
# to make sure the parser advances
if self.values and self.values[0] == "f":
self.next_line()
def consume_faces(self, collected_faces = None):
"""
Consume all consecutive faces
If more than three vertices are specified, we triangulate by the following procedure:
Let the face have n vertices in the order v_1 v_2 v_3 ... v_n, n >= 3.
We emit the first face as usual: (v_1, v_2, v_3). For each remaining vertex v_j,
j > 3, we emit (v_j, v_1, v_{j - 1}), e.g. (v_4, v_1, v_3), (v_5, v_1, v_4).
In a perfect world we could consume all vertices straight forward and draw using
GL_TRIANGLE_FAN (which exactly matches the procedure above).
This is however rarely the case.
* If the face is co-planar but concave, then you need to triangulate the face.
* If the face is not-coplanar, you are screwed, because OBJ doesn't preserve enough information
to know what tessellation was intended.
We always triangulate to make it simple.
:param collected_faces: A list into which all (possibly triangulated) faces will be written in the form
of triples of the corresponding absolute vertex IDs. These IDs index the list
self.wavefront.vertices.
Specify None to prevent consuming faces (and thus saving memory usage).
"""
# Helper tuple and function
Vertex = namedtuple('Vertex', 'idx pos color uv normal')
def emit_vertex(vertex):
# Just yield all the values except for the index
for v in vertex.uv:
yield v
for v in vertex.color:
yield v
for v in vertex.normal:
yield v
for v in vertex.pos:
yield v
# Figure out the format of the first vertex
# We raise an exception if any following vertex has a different format
# NOTE: Order is always v/vt/vn where v is mandatory and vt and vn is optional
has_vt = False
has_vn = False
has_colors = False
parts = self.values[1].split('/')
# We assume texture coordinates are present
if len(parts) == 2:
has_vt = True
# We have a vn, but not necessarily a vt
elif len(parts) == 3:
# Check for empty vt "1//1"
if parts[1] != '':
has_vt = True
has_vn = True
# Are we referencing vertex with color info?
vindex = int(parts[0])
if vindex < 0:
vindex += len(self.wavefront.vertices)
else:
vindex -= 1
vertex = self.wavefront.vertices[vindex]
has_colors = len(vertex) == 6
# Prepare vertex format string
vertex_format = "_".join(e[0] for e in [
("T2F", has_vt),
("C3F", has_colors),
("N3F", has_vn),
("V3F", True)
] if e[1])
# If the material already have vertex data, ensure the same format is used
if self.material.vertex_format and self.material.vertex_format != vertex_format:
# raise ValueError((
if self.warn_material:
logger.warn(
"Trying to merge vertex data with different format: {}. "
"Material {} has vertex format {}"
.format(vertex_format, self.material.name, self.material.vertex_format)
)
self.material.vertex_format = vertex_format
# The first iteration processes the current/first f statement.
# The loop continues until there are no more f-statements or StopIteration is raised by generator
while True:
# The very first vertex, the last encountered and the current one
v1, vlast, vcurrent = None, None, None
for i, v in enumerate(self.values[1:]):
parts = v.split('/')
v_index = (int(parts[0]) - 1)
# uv field might be blank
try:
t_index = (int(parts[1]) - 1) if has_vt else None
except ValueError:
t_index = 0
try:
n_index = (int(parts[2]) - 1) if has_vn else None
except ValueError:
n_index = 0
# Resolve negative index lookups
if v_index < 0:
v_index += len(self.wavefront.vertices) + 1
if has_vt and t_index < 0:
t_index += len(self.tex_coords) + 1
if has_vn and n_index < 0:
n_index += len(self.normals) + 1
vlast = vcurrent
vcurrent = Vertex(
idx = v_index,
pos = self.wavefront.vertices[v_index][0:3] if has_colors else self.wavefront.vertices[v_index],
color = self.wavefront.vertices[v_index][3:] if has_colors else (),
uv = self.tex_coords[t_index] if has_vt and t_index < len(self.tex_coords) else (),
normal = self.normals[n_index] if has_vn and n_index < len(self.normals) else ()
)
yield from emit_vertex(vcurrent)
# Triangulation when more than 3 elements are present
if i >= 3:
# The current vertex has already been emitted.
# Now just emit the first and the third vertices from the face
yield from emit_vertex(v1)
yield from emit_vertex(vlast)
if i == 0:
# Store the first vertex
v1 = vcurrent
if (collected_faces is not None) and (i >= 2):
if i == 2:
# Append the first triangle face in usual order (i.e. as specified in the Wavefront file)
collected_faces.append([v1.idx, vlast.idx, vcurrent.idx])
if i >= 3:
# Triangulate the remaining part of the face by putting the current, the first
# and the last parsed vertex in that order as a new face.
# This order coincides deliberately with the order from vertex yielding above.
collected_faces.append([vcurrent.idx, v1.idx, vlast.idx])
# Break out of the loop when there are no more f statements
try:
self.next_line()
except StopIteration:
break
if not self.values:
break
if self.values[0] != "f":
break
class ObjParser(Parser):
"""This parser parses lines from .obj files."""
def __init__(self,
wavefront,
file_name,
strict=False,
encoding="utf-8",
create_materials=False,
parse=True):
"""
Create a new obj parser
:param wavefront: The wavefront object
:param file_name: file name and path of obj file to read
:param strict: Enable strict mode
:param encoding: Encoding to read the text files
:param create_materials: Create materials if they don't exist
:param parse: Should parse be called immediately or manually called later?
"""
super(ObjParser, self).__init__(file_name,
strict=strict,
encoding=encoding)
self.wavefront = wavefront
self.mesh = None
self.material = None
self.create_materials = create_materials
# Stores ALL vertices, normals and texcoords for the entire file
self.vertices = []
self.normals = []
self.tex_coords = []
if parse:
self.parse()
# methods for parsing types of wavefront lines
def parse_v(self):
self.vertices += list(self.consume_vertices())
def consume_vertices(self):
"""
Consumes all consecutive vertices.
NOTE: There is no guarantee this will consume all vertices since other
statements can also occur in the vertex list
"""
while True:
# Vertex color
if len(self.values) == 7:
yield (
float(self.values[1]),
float(self.values[2]),
float(self.values[3]),
float(self.values[4]),
float(self.values[5]),
float(self.values[6]),
)
# Positions only
else:
yield (
float(self.values[1]),
float(self.values[2]),
float(self.values[3]),
)
self.next_line()
if not self.values:
break
if self.values[0] != "v":
break
def parse_vn(self):
self.normals += list(self.consume_normals())
# Since list() also consumes StopIteration we need to sanity check the line
# to make sure the parser advances
if self.values and self.values[0] == "vn":
self.next_line()
def consume_normals(self):
"""Consumes all consecutive texture coordinate lines"""
# The first iteration processes the current/first vn statement.
# The loop continues until there are no more vn-statements or StopIteration is raised by generator
while True:
yield (
float(self.values[1]),
float(self.values[2]),
float(self.values[3]),
)
self.next_line()
if not self.values:
break
if self.values[0] != "vn":
break
def parse_vt(self):
self.tex_coords += list(self.consume_texture_coordinates())
# Since list() also consumes StopIteration we need to sanity check the line
# to make sure the parser advances
if self.values[0] == "vt":
self.next_line()
def consume_texture_coordinates(self):
"""Consume all consecutive texture coordinates"""
# The first iteration processes the current/first vt statement.
# The loop continues until there are no more vt-statements or StopIteration is raised by generator
while True:
yield (
float(self.values[1]),
float(self.values[2]),
)
self.next_line()
if not self.values:
break
if self.values[0] != "vt":
break
@auto_consume
def parse_mtllib(self):
mtllib = os.path.join(self.dir, " ".join(self.values[1:]))
try:
materials = MaterialParser(mtllib,
encoding=self.encoding,
strict=self.strict).materials
except IOError:
if self.create_materials:
return
raise
for name, material in materials.items():
self.wavefront.materials[name] = material
@auto_consume
def parse_usemtl(self):
name = " ".join(self.values[1:])
self.material = self.wavefront.materials.get(name, None)
if self.material is None:
if not self.create_materials:
raise PywavefrontException('Unknown material: %s' % name)
# Create a new default material if configured to resolve missing ones
self.material = Material(name=name, is_default=True)
self.wavefront.materials[name] = self.material
if self.mesh is not None:
self.mesh.add_material(self.material)
def parse_usemat(self):
self.parse_usemtl()
@auto_consume
def parse_o(self):
self.mesh = Mesh(self.values[1])
self.wavefront.add_mesh(self.mesh)
def parse_f(self):
# Add default material if not created
if self.material is None:
self.material = Material(is_default=True)
self.wavefront.materials[self.material.name] = self.material
# Support objects without `o` statement
if self.mesh is None:
self.mesh = Mesh()
self.wavefront.add_mesh(self.mesh)
self.mesh.add_material(self.material)
self.mesh.add_material(self.material)
self.material.vertices += list(self.consume_faces())
# Since list() also consumes StopIteration we need to sanity check the line
# to make sure the parser advances
if self.values and self.values[0] == "f":
self.next_line()
def consume_faces(self):
"""
Consume all consecutive faces
If a 4th vertex is specified, we triangulate.
In a perfect world we could consume this straight forward and draw using GL_TRIANGLE_FAN.
This is however rarely the case..
* If the face is co-planar but concave, then you need to triangulate the face
* If the face is not-coplanar, you are screwed, because OBJ doesn't preserve enough information
to know what tessellation was intended
We always triangulate to make it simple
"""
# Figure out the format of the first vertex
# We raise an exception if any following vertex has a different format
# NOTE: Order is always v/vt/vn where v is mandatory and vt and vn is optional
has_vt = False
has_vn = False
has_colors = False
parts = self.values[1].split('/')
# We assume texture coordinates are present
if len(parts) == 2:
has_vt = True
# We have a vn, but not necessarily a vt
elif len(parts) == 3:
# Check for empty vt "1//1"
if parts[1] != '':
has_vt = True
has_vn = True
# Are we referencing vertex with color info?
vertex = self.vertices[int(parts[0]) - 1]
has_colors = len(vertex) == 6
# Prepare vertex format string
vertex_format = "_".join(
e[0]
for e in [("T2F", has_vt), ("C3F",
has_colors), ("N3F",
has_vn), ("V3F", True)]
if e[1])
# If the material already have vertex data, ensure the same format is used
if self.material.vertex_format and self.material.vertex_format != vertex_format:
raise ValueError(
("Trying to merge vertex data with different format: {}. "
"Material {} has vertex format {}").format(
vertex_format, self.material.name,
self.material.vertex_format))
self.material.vertex_format = vertex_format
# The first iteration processes the current/first f statement.
# The loop continues until there are no more f-statements or StopIteration is raised by generator
while True:
v1, vlast = None, None
# Do we need to triangulate? Each line may contain a varying amount of elements
triangulate = (len(self.values) - 1) > 3
for i, v in enumerate(self.values[1:]):
parts = v.split('/')
v_index = (int(parts[0]) - 1)
t_index = (int(parts[1]) - 1) if has_vt else None
n_index = (int(parts[2]) - 1) if has_vn else None
# Resolve negative index lookups
if v_index < 0:
v_index += len(self.vertices) - 1
if has_vt and t_index < 0:
t_index += len(self.tex_coords) - 1
if has_vn and n_index < 0:
n_index += len(self.normals) - 1
pos = self.vertices[v_index][
0:3] if has_colors else self.vertices[v_index]
color = self.vertices[v_index][3:] if has_colors else ()
uv = self.tex_coords[t_index] if has_vt else ()
normal = self.normals[n_index] if has_vn else ()
# Just yield all the values
for v in uv:
yield v
for v in color:
yield v
for v in normal:
yield v
for v in pos:
yield v
# Triangulation when more than 3 elements is present
if triangulate:
if i >= 3:
# Emit vertex 1 and 3 triangulating when a 4th vertex is specified
for v in v1:
yield v
for v in vlast:
yield v
if i == 0:
# Store the first vertex
v1 = uv + color + normal + pos
# Store the last vertex
vlast = uv + color + normal + pos
# Break out of the loop when there are no more f statements
self.next_line()
if not self.values:
break
if self.values[0] != "f":
break