mesh_edgetools.py

# Blender EdgeTools
#
# This is a toolkit for edge manipulation based on several of mesh manipulation
# abilities of several CAD/CAE packages, notably CATIA's Geometric Workbench
# from which most of these tools have a functional basis based on the paradims
# that platform enables.  These tools are a collection of scripts that I needed
# at some point, and so I will probably add and improve these as I continue to
# use and model with them.
#
# It might be good to eventually merge the tinyCAD VTX tools for unification
# purposes, and as these are edge-based tools, it would make sense.  Or maybe
# merge this with tinyCAD instead?
#
# The GUI and Blender add-on structure shamelessly coded in imitation of the
# LoopTools addon.
#
# Examples:
#   - "Ortho" inspired from CATIA's line creation tool which creates a line of a
#       user specified length at a user specified angle to a curve at a chosen
#       point.  The user then selects the plane the line is to be created in.
#   - "Shaft" is inspired from CATIA's tool of the same name.  However, instead
#       of a curve around an axis, this will instead shaft a line, a point, or
#       a fixed radius about the selected axis.
#   - "Slice" is from CATIA's ability to split a curve on a plane.  When
#       completed this be a Python equivalent with all the same basic
#       functionality, though it will sadly be a little clumsier to use due
#       to Blender's selection limitations.
#
# Notes:
#   - Buggy parts have been hidden behind bpy.app.debug.  Run Blender in debug
#       to expose those.  Example: Shaft with more than two edges selected.
#   - Some functions have started to crash, despite working correctly before.
#       What could be causing that?  Blender bug?  Or coding bug?
#
# Paul "BrikBot" Marshall
# Created: January 28, 2012
# Last Modified: October 6, 2012
# Homepage (blog): http://post.darkarsenic.com/
#                       //blog.darkarsenic.com/
#
# Coded in IDLE, tested in Blender 2.6.
# Search for "@todo" to quickly find sections that need work.
#
# Remeber -
#   Functional code comes before fast code.  Once it works, then worry about
#   making it faster/more efficient.
#
# ##### BEGIN GPL LICENSE BLOCK #####
#
#  The Blender Edgetools is to bring CAD tools to Blender.
#  Copyright (C) 2012  Paul Marshall
#
#  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 3 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, see <http://www.gnu.org/licenses/>.
#
# ##### END GPL LICENSE BLOCK #####

# <pep8 compliant>
# ^^ Maybe. . . . :P

bl_info = {
    "name": "EdgeTools",
    "author": "Paul Marshall",
    "version": (0, 8),
    "blender": (2, 68, 0),
    "location": "View3D > Toolbar and View3D > Specials (W-key)",
    "warning": "",
    "description": "CAD style edge manipulation tools",
    "wiki_url": "http://wiki.blender.org/index.php/Extensions:2.6/Py/"
        "Scripts/Modeling/EdgeTools",
    "tracker_url": "",
    "category": "Mesh"}


import bpy, bmesh, mathutils
from math import acos, pi, radians, sqrt, tan
from mathutils import Matrix, Vector
from mathutils.geometry import (distance_point_to_plane,
                                interpolate_bezier,
                                intersect_point_line,
                                intersect_line_line,
                                intersect_line_plane)
from bpy.props import (BoolProperty,
                       BoolVectorProperty,
                       IntProperty,
                       FloatProperty,
                       EnumProperty)

integrated = False

# Quick an dirty method for getting the sign of a number:
def sign(number):
    return (number > 0) - (number < 0)


# is_parallel
#
# Checks to see if two lines are parallel
def is_parallel(v1, v2, v3, v4):
    result = intersect_line_line(v1, v2, v3, v4)
    return result == None


# is_axial
#
# This is for the special case where the edge is parallel to an axis.  In this
# the projection onto the XY plane will fail so it will have to be handled
# differently.  This tells us if and how:
def is_axial(v1, v2, error = 0.000002):
    vector = v2 - v1
    # Don't need to store, but is easier to read:
    vec0 = vector[0] > -error and vector[0] < error
    vec1 = vector[1] > -error and vector[1] < error
    vec2 = vector[2] > -error and vector[2] < error
    if (vec0 or vec1) and vec2:
        return 'Z'
    elif vec0 and vec1:
        return 'Y'
    return None


# is_same_co
#
# For some reason "Vector = Vector" does not seem to look at the actual
# coordinates.  This provides a way to do so.
def is_same_co(v1, v2):
    if len(v1) != len(v2):
        return False
    else:
        for co1, co2 in zip(v1, v2):
            if co1 != co2:
                return False
    return True


# is_face_planar
#
# Tests a face to see if it is planar.
def is_face_planar(face, error = 0.0005):
    for v in face.verts:
        d = distance_point_to_plane(v.co, face.verts[0].co, face.normal)
        if bpy.app.debug:
            print("Distance: " + str(d))
        if d < -error or d > error:
            return False
    return True


# other_joined_edges
#
# Starts with an edge.  Then scans for linked, selected edges and builds a
# list with them in "order", starting at one end and moving towards the other.
def order_joined_edges(edge, edges = [], direction = 1):
    if len(edges) == 0:
        edges.append(edge)
        edges[0] = edge

    if bpy.app.debug:
        print(edge, end = ", ")
        print(edges, end = ", ")
        print(direction, end = "; ")

    # Robustness check: direction cannot be zero
    if direction == 0:
        direction = 1

    newList = []
    for e in edge.verts[0].link_edges:
        if e.select and edges.count(e) == 0:
            if direction > 0:
                edges.insert(0, e)
                newList.extend(order_joined_edges(e, edges, direction + 1))
                newList.extend(edges)
            else:
                edges.append(e)
                newList.extend(edges)
                newList.extend(order_joined_edges(e, edges, direction - 1))

    # This will only matter at the first level:
    direction = direction * -1

    for e in edge.verts[1].link_edges:
        if e.select and edges.count(e) == 0:
            if direction > 0:
                edges.insert(0, e)
                newList.extend(order_joined_edges(e, edges, direction + 2))
                newList.extend(edges)
            else:
                edges.append(e)
                newList.extend(edges)