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mightyscape-1.1-deprecated/extensions/fablabchemnitz/import_3d_mesh/import_3d_mesh.py

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#!/usr/bin/env python3
#
# Copyright (C) 2007 John Beard john.j.beard@gmail.com
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
#
"""
This extension draws 3d objects from a Wavefront .obj 3D file stored in a local folder
Many settings for appearance, lighting, rotation, etc are available.
^y
|
__--``| |_--``| __--
__--`` | __--``| |_--``
| z | | |_--``|
| <----|--------|-----_0-----|----------------
| | |_--`` | |
| __--`` <-``| |_--``
|__--`` x |__--``|
IMAGE PLANE SCENE|
|
Vertices are given as "v" followed by three numbers (x,y,z).
All files need a vertex list
v x.xxx y.yyy z.zzz
Faces are given by a list of vertices
(vertex 1 is the first in the list above, 2 the second, etc):
f 1 2 3
Edges are given by a list of vertices. These will be broken down
into adjacent pairs automatically.
l 1 2 3
Faces are rendered according to the painter's algorithm and perhaps
back-face culling, if selected. The parameter to sort the faces by
is user-selectable between max, min and average z-value of the vertices
"""
import os
from math import acos, cos, floor, pi, sin, sqrt
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import numpy
import tempfile
import openmesh as om
import inkex
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from inkex import Group, Circle, Color
from inkex.utils import pairwise
from inkex.paths import Move, Line
def draw_circle(r, cx, cy, width, fill, name, parent):
"""Draw an SVG circle"""
circle = parent.add(Circle(cx=str(cx), cy=str(cy), r=str(r)))
circle.style = {'stroke': '#000000', 'stroke-width': str(width), 'fill': fill}
circle.label = name
def draw_line(x1, y1, x2, y2, width, name, parent):
elem = parent.add(inkex.PathElement())
elem.style = {'stroke': '#000000', 'stroke-width': str(width), 'fill': 'none',
'stroke-linecap': 'round'}
elem.set('inkscape:label', name)
elem.path = [Move(x1, y1), Line(x2, y2)]
def draw_poly(pts, face, st, name, parent):
"""Draw polygone"""
style = {'stroke': '#000000', 'stroke-width': str(st.th), 'stroke-linejoin': st.linejoin,
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'stroke-opacity': st.s_opac, 'fill': st.fill, 'fill-opacity': st.fill_opacity}
path = inkex.Path()
for facet in face:
if not path: # for first point
path.append(Move(pts[facet - 1][0], -pts[facet - 1][1]))
else:
path.append(Line(pts[facet - 1][0], -pts[facet - 1][1]))
path.close()
poly = parent.add(inkex.PathElement())
poly.label = name
poly.style = style
poly.path = path
def draw_edges(edge_list, pts, st, parent):
for edge in edge_list: # for every edge
pt_1 = pts[edge[0] - 1][0:2] # the point at the start
pt_2 = pts[edge[1] - 1][0:2] # the point at the end
name = 'Edge' + str(edge[0]) + '-' + str(edge[1])
draw_line(pt_1[0], -pt_1[1], pt_2[0], -pt_2[1], st.th, name, parent)
def draw_faces(faces_data, pts, obj, shading, fill_col, st, parent):
for face in faces_data: # for every polygon that has been sorted
if shading:
st.fill = get_darkened_colour(fill_col, face[1] / pi) # darken proportionally to angle to lighting vector
else:
st.fill = get_darkened_colour(fill_col, 1) # do not darken colour
face_no = face[3] # the number of the face to draw
draw_poly(pts, obj.fce[face_no], st, 'Face:' + str(face_no), parent)
def get_darkened_colour(rgb, factor):
"""return a hex triplet of colour, reduced in lightness 0.0-1.0"""
return '#' + "%02X" % floor(factor * rgb[0]) \
+ "%02X" % floor(factor * rgb[1]) \
+ "%02X" % floor(factor * rgb[2]) # make the colour string
def make_rotation_log(options):
"""makes a string recording the axes and angles of each rotation, so an object can be repeated"""
return options.r1_ax + str('%.2f' % options.r1_ang) + ':' + \
options.r2_ax + str('%.2f' % options.r2_ang) + ':' + \
options.r3_ax + str('%.2f' % options.r3_ang) + ':' + \
options.r1_ax + str('%.2f' % options.r4_ang) + ':' + \
options.r2_ax + str('%.2f' % options.r5_ang) + ':' + \
options.r3_ax + str('%.2f' % options.r6_ang)
def normalise(vector):
"""return the unit vector pointing in the same direction as the argument"""
length = sqrt(numpy.dot(vector, vector))
return numpy.array(vector) / length
def get_normal(pts, face):
"""normal vector for the plane passing though the first three elements of face of pts"""
return numpy.cross(
(numpy.array(pts[face[0] - 1]) - numpy.array(pts[face[1] - 1])),
(numpy.array(pts[face[0] - 1]) - numpy.array(pts[face[2] - 1])),
).flatten()
def get_unit_normal(pts, face, cw_wound):
"""
Returns the unit normal for the plane passing through the
first three points of face, taking account of winding
"""
# if it is clockwise wound, reverse the vector direction
winding = -1 if cw_wound else 1
return winding * normalise(get_normal(pts, face))
def rotate(matrix, rads, axis):
"""choose the correct rotation matrix to use"""
if axis == 'x':
trans_mat = numpy.array([
[1, 0, 0], [0, cos(rads), -sin(rads)], [0, sin(rads), cos(rads)]])
elif axis == 'y':
trans_mat = numpy.array([
[cos(rads), 0, sin(rads)], [0, 1, 0], [-sin(rads), 0, cos(rads)]])
elif axis == 'z':
trans_mat = numpy.array([
[cos(rads), -sin(rads), 0], [sin(rads), cos(rads), 0], [0, 0, 1]])
return numpy.matmul(trans_mat, matrix)
class Style(object): # container for style information
def __init__(self, options):
self.th = options.th
self.fill = '#ff0000'
self.col = '#000000'
self.r = 2
self.s_opac = str(options.s_opac / 100.0)
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self.fill_opacity = options.fill_color.alpha
self.linecap = 'round'
self.linejoin = 'round'
class WavefrontObj(object):
"""Wavefront based 3d object defined by the vertices and the faces (eg a polyhedron)"""
name = property(lambda self: self.meta.get('name', None))
def __init__(self, filename):
self.meta = {
'name': os.path.basename(filename).rsplit('.', 1)[0]
}
self.vtx = []
self.edg = []
self.fce = []
self._parse_file(filename)
def _parse_file(self, filename):
if not os.path.isfile(filename):
raise IOError("Can't find wavefront object file {}".format(filename))
with open(filename, 'r') as fhl:
for line in fhl:
self._parse_line(line.strip())
def _parse_line(self, line):
if line.startswith('#'):
if ':' in line:
name, value = line.split(':', 1)
self.meta[name.lower()] = value
elif line:
(kind, line) = line.split(None, 1)
kind_name = 'add_' + kind
if hasattr(self, kind_name):
getattr(self, kind_name)(line)
@staticmethod
def _parse_numbers(line, typ=str):
# Ignore any slash options and always pick the first one
return [typ(v.split('/')[0]) for v in line.split()]
def add_v(self, line):
"""Add vertex from parsed line"""
vertex = self._parse_numbers(line, float)
if len(vertex) == 3:
self.vtx.append(vertex)
def add_l(self, line):
"""Add line from parsed line"""
vtxlist = self._parse_numbers(line, int)
# we need at least 2 vertices to make an edge
if len(vtxlist) > 1:
# we can have more than one vertex per line - get adjacent pairs
self.edg.append(pairwise(vtxlist))
def add_f(self, line):
"""Add face from parsed line"""
vtxlist = self._parse_numbers(line, int)
# we need at least 3 vertices to make an edge
if len(vtxlist) > 2:
self.fce.append(vtxlist)
def get_transformed_pts(self, trans_mat):
"""translate vertex points according to the matrix"""
transformed_pts = []
for vtx in self.vtx:
transformed_pts.append((numpy.matmul(trans_mat, numpy.array(vtx).T)).T.tolist())
return transformed_pts
def get_edge_list(self):
"""make an edge vertex list from an existing face vertex list"""
edge_list = []
for face in self.fce:
for j, edge in enumerate(face):
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# Ascending order of vertices (for duplicate detection)
edge_list.append(sorted([edge, face[(j + 1) % len(face)]]))
return [list(x) for x in sorted(set(tuple(x) for x in edge_list))]
class Import3DMesh(inkex.GenerateExtension):
"""Generate a polyhedron from a wavefront 3d model file"""
def add_arguments(self, pars):
pars.add_argument("--tab", default="object")
# MODEL FILE SETTINGS
pars.add_argument("--obj", default='cube')
pars.add_argument("--input_choice", default='default')
pars.add_argument("--spec_file", default='great_rhombicuboct.obj')
pars.add_argument("--cw_wound", type=inkex.Boolean, default=True)
pars.add_argument("--type", default='face')
# VEIW SETTINGS
pars.add_argument("--r1_ax", default="x")
pars.add_argument("--r2_ax", default="x")
pars.add_argument("--r3_ax", default="x")
pars.add_argument("--r4_ax", default="x")
pars.add_argument("--r5_ax", default="x")
pars.add_argument("--r6_ax", default="x")
pars.add_argument("--r1_ang", type=float, default=0.0)
pars.add_argument("--r2_ang", type=float, default=0.0)
pars.add_argument("--r3_ang", type=float, default=0.0)
pars.add_argument("--r4_ang", type=float, default=0.0)
pars.add_argument("--r5_ang", type=float, default=0.0)
pars.add_argument("--r6_ang", type=float, default=0.0)
pars.add_argument("--scl", type=float, default=100.0)
# STYLE SETTINGS
pars.add_argument("--show", type=self.arg_method('gen'))
pars.add_argument("--shade", type=inkex.Boolean, default=True)
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pars.add_argument("--fill_color", type=Color, default='1943148287', help="Fill color")
pars.add_argument("--s_opac", type=int, default=100)
pars.add_argument("--th", type=float, default=2)
pars.add_argument("--lv_x", type=float, default=1)
pars.add_argument("--lv_y", type=float, default=1)
pars.add_argument("--lv_z", type=float, default=-2)
pars.add_argument("--back", type=inkex.Boolean, default=False)
pars.add_argument("--z_sort", type=self.arg_method('z_sort'), default=self.z_sort_min)
def get_filename(self):
"""Get the filename for the spec file"""
if self.options.input_choice == 'custom':
return self.options.spec_file
if self.options.input_choice == 'default':
moddir = self.ext_path()
return os.path.join(moddir, 'Poly3DObjects', self.options.obj + '.obj')
def generate(self):
so = self.options
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if not os.path.exists(self.get_filename()):
inkex.utils.debug("The input file does not exist.")
exit(1)
input_mesh = om.read_polymesh(self.get_filename()) #read input file
output_obj = os.path.join(tempfile.gettempdir(), "input_mesh.obj")
om.write_mesh(output_obj, input_mesh)
#write to obj file
obj = WavefrontObj(output_obj)
scale = self.svg.unittouu('1px') # convert to document units
st = Style(so) # initialise style
# we will put all the rotations in the object name, so it can be repeated in
poly = Group.new(obj.name + ':' + make_rotation_log(so))
(pos_x, pos_y) = self.svg.namedview.center
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#poly.transform.add_translate(pos_x, pos_y)
poly.transform.add_scale(scale)
# TRANSFORMATION OF THE OBJECT (ROTATION, SCALE, ETC)
trans_mat = numpy.identity(3, float) # init. trans matrix as identity matrix
for i in range(1, 7): # for each rotation
axis = getattr(so, 'r{}_ax'.format(i))
angle = getattr(so, 'r{}_ang'.format(i)) * pi / 180
trans_mat = rotate(trans_mat, angle, axis)
# scale by linear factor (do this only after the transforms to reduce round-off)
trans_mat = trans_mat * so.scl
# the points as projected in the z-axis onto the viewplane
transformed_pts = obj.get_transformed_pts(trans_mat)
so.show(obj, st, poly, transformed_pts)
return poly
def gen_vtx(self, obj, st, poly, transformed_pts):
"""Generate Vertex"""
for i, pts in enumerate(transformed_pts):
draw_circle(st.r, pts[0], pts[1], st.th, '#000000', 'Point' + str(i), poly)
def gen_edg(self, obj, st, poly, transformed_pts):
"""Generate edges"""
# we already have an edge list
edge_list = obj.edg
if obj.fce:
# we must generate the edge list from the faces
edge_list = obj.get_edge_list()
draw_edges(edge_list, transformed_pts, st, poly)
def gen_fce(self, obj, st, poly, transformed_pts):
"""Generate face"""
so = self.options
# colour tuple for the face fill
# unit light vector
lighting = normalise((so.lv_x, -so.lv_y, so.lv_z))
# we have a face list
if obj.fce:
z_list = []
for i, face in enumerate(obj.fce):
# get the normal vector to the face
norm = get_unit_normal(transformed_pts, face, so.cw_wound)
# get the angle between the normal and the lighting vector
angle = acos(numpy.dot(norm, lighting))
z_sort_param = so.z_sort(transformed_pts, face)
# include all polygons or just the front-facing ones as needed
if so.back or norm[2] > 0:
# record the maximum z-value of the face and angle to
# light, along with the face ID and normal
z_list.append((z_sort_param, angle, norm, i))
z_list.sort(key=lambda x: x[0]) # sort by ascending sort parameter of the face
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draw_faces(z_list, transformed_pts, obj, so.shade, self.options.fill_color, st, poly)
else: # we cannot generate a list of faces from the edges without a lot of computation
raise inkex.AbortExtension("Face data not found.")
@staticmethod
def z_sort_max(pts, face):
"""returns the largest z_value of any point in the face"""
return max([pts[facet - 1][2] for facet in face])
@staticmethod
def z_sort_min(pts, face):
"""returns the smallest z_value of any point in the face"""
return min([pts[facet - 1][2] for facet in face])
@staticmethod
def z_sort_cent(pts, face):
"""returns the centroid z_value of any point in the face"""
return sum([pts[facet - 1][2] for facet in face]) / len(face)
if __name__ == '__main__':
Import3DMesh().run()