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[ArchWall] getExtrusionData() fix normal problem by adding get_shape_normal() (#12603)

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* [ArchWall] getExtrusionData() fix normal problem by adding get_shape_normal()

In geometry.py
- added get_shape_normal()
- fixed is_straight_line()
DraftGeomUtils.py
- added get_shape_normal()

FC Discussion - https://forum.freecad.org/viewtopic.php?p=726101#p726101

* [ArchWall] getExtrusionData() fix normal problem

Follow-up following discussion at https://github.com/FreeCAD/FreeCAD/pull/12603

- delete trailing whitespaces
- put Part.makePolygon() in try statement
- study and findings at https://github.com/FreeCAD/FreeCAD/pull/12603#issuecomment-1969277743

In geometry.py
- added get_shape_normal()
- fixed is_straight_line()
DraftGeomUtils.py
- added get_shape_normal()

FC Discussion - https://forum.freecad.org/viewtopic.php?p=726101#p726101

* Update geometry.py

* Update geometry.py

* Update geometry.py

---------

Co-authored-by: Yorik van Havre <yorik@uncreated.net>
This commit is contained in:
paul
2024-04-02 17:54:27 +08:00
committed by GitHub
parent 581dee4d48
commit d3d18ac7e0
3 changed files with 87 additions and 1 deletions
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7
src/Mod/Arch/ArchWall.py
View File

@@ -1210,7 +1210,10 @@ class _Wall(ArchComponent.Component):
if not height:
return None
if obj.Normal == Vector(0,0,0):
normal = Vector(0,0,1)
import DraftGeomUtils
normal = DraftGeomUtils.get_shape_normal(obj.Base.Shape)
if normal == None:
normal = Vector(0,0,1)
else:
normal = Vector(obj.Normal)
base = None
@@ -1275,8 +1278,10 @@ class _Wall(ArchComponent.Component):
# If the object is a single edge, use that as the
# basewires.
# TODO 2023.11.26: Need to check if it isn't Sketch after all first
# or use algorithm for Sketch altogether?
elif len(obj.Base.Shape.Edges) == 1:
self.basewires = [Part.Wire(obj.Base.Shape.Edges)]

1
src/Mod/Draft/DraftGeomUtils.py
View File

@@ -70,6 +70,7 @@ from draftgeoutils.geometry import (findPerpendicular,
get_spline_normal,
getNormal,
get_normal,
get_shape_normal,
getRotation,
isPlanar,
is_planar,

80
src/Mod/Draft/draftgeoutils/geometry.py
View File

@@ -219,6 +219,65 @@ def get_spline_normal(edge, tol=-1):
return None
def get_shape_normal(shape):
"""Find the normal of a shape or list of points or colinear edges, if possible."""
# New function based on get_normal() drafted by @Roy_043
# in discussion https://forum.freecad.org/viewtopic.php?p=717862#p717862
#
# The normal would not be affected by the 3D view direction and flipped as
# get_normal would be. Placement of the Shape is taken into account in this
# new function instead :
# - Normal of a planar shape is usually bi-directional, this function return
# the one 'in the direction' of the shape's placement 'normal' (z-direction).
# As reference, shape.findPlane() favour positive axes, get_normal()
# favour the 'view direction' (obtained by getViewDirection() ).
# - Even when the Shape is an edge or colinear edges, its Placement is taken
# into account, and this function return one 'in the direction' of the
# shape's placement 'normal' (z-direction).
# https://forum.freecad.org/viewtopic.php?p=715850#p715850
# The normal direction of a Draft wire (co-planar) or arc used to depends on
# the way the shape is constructed i.e. by vertexes in clockwise or
# anti-clockwise. This cryptic behaviour no longer matters.
if shape.isNull():
return None
# Roy_043's remarks on the behavior of Shape.findPlane():
# - https://forum.freecad.org/viewtopic.php?p=713993#p713993
# Check if the shape is planar
# If True: check if the outer wire is closed:
# if True : Return a (plane with) normal based on the direction of the outer wire (CW or CCW).
# if False : ? Return a (plane with) normal that points towards positive global axes with a certain priority
# (probably? Z, Y and then X).
# If False: return None.
#
# Further remarks :
# - Tested Sketch with 2 colinear edges return a Plane with Axis
# - Tested Sketch with 1 edge return no Plane with no Axis
shape_rot = shape.Placement.Rotation
if is_straight_line(shape):
start_edge = shape.Edges[0]
x_vec = start_edge.tangentAt(start_edge.FirstParameter) # Return vector is in global coordinate
local_x_vec = shape_rot.inverted().multVec(x_vec) #
local_rot = App.Rotation(local_x_vec, App.Vector(0, 1, 0), App.Vector(0, 0, 1), "XZY")
# see https://blog.freecad.org/2023/01/16/the-rotation-api-in-freecad/ for App.Rotation(vecx, vecy, vecz, string)
# discussion - https://forum.freecad.org/viewtopic.php?p=717738#p717738
return shape_rot.multiply(local_rot).multVec(App.Vector(0, 0, 1))
else:
plane = shape.findPlane()
normal = plane.Axis
shape_normal = shape_rot.multVec(App.Vector(0, 0, 1))
# Now, check the normal direction of the plane (plane.Axis).
# The final deduced normal should be 'in the direction' of the z-direction of the shape's placement,
# if plane.Axis is in the 'opposite' direction of the Z direction of the shape's placement, reverse it.
if normal.getAngle(shape_normal) > math.pi/2:
normal = normal.negative()
return normal
def get_normal(shape, tol=-1):
"""Find the normal of a shape or list of points, if possible."""
@@ -329,6 +388,8 @@ def is_straight_line(shape, tol=-1):
if len(shape.Edges) >= 1:
start_edge = shape.Edges[0]
dir_start_edge = start_edge.tangentAt(start_edge.FirstParameter)
point_start_edge = start_edge.firstVertex().Point
#set tolerance
if tol <=0:
err = shape.globalTolerance(tol)
@@ -343,6 +404,25 @@ def is_straight_line(shape, tol=-1):
# because sin(x) = x + O(x**3), for small angular deflection it's
# enough use the cross product of directions (or dot with a normal)
if (abs(edge.Length - first_point.distanceToPoint(last_point)) > err
# https://forum.freecad.org/viewtopic.php?p=726101#p726101
# Shape with parallel edges but not colinear used to return True
# by this function, below line added fixes this bug.
# Further remark on the below fix :
# - get_normal() use this function, may had created problems
# previously but not reported; on the other hand, this fix
# seems have no 'regression' created as get_normal use
# plane.Axis (with 3DView check). See get_shape_normal()
# which take into account shape's placement
# - other functions had been using this also : Keep In View to
# see if there is 'regression' :
#
# $ grep -rni "is_straight" ./
# ./draftfunctions/upgrade.py
# ./draftgeoutils/geometry.py
# ./draftmake/make_wire.py
or first_point.distanceToLine(point_start_edge, dir_start_edge) > err \
#
or dir_start_edge.cross(dir_edge).Length > err):
return False