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[Draft]PathArray TangentVector & gimbal lock

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- allows user to specify orientation of copies
- prevents gimbal lock by using Base.Rotation instead of
  YRP transforms
This commit is contained in:
wandererfan
2020-04-30 07:45:25 -04:00
committed by WandererFan
parent 9394da9132
commit a77c4b7b2e
1 changed files with 22 additions and 56 deletions
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78
src/Mod/Draft/Draft.py
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@@ -2338,75 +2338,29 @@ def calculatePlacement(globalRotation, edge, offset, RefPt, xlate, align, normal
if not align:
return placement
# unit +Z Probably defined elsewhere?
z = FreeCAD.Vector(0, 0, 1)
# y = FreeCAD.Vector(0, 1, 0) # unit +Y
x = FreeCAD.Vector(1, 0, 0) # unit +X
nullv = FreeCAD.Vector(0, 0, 0)
# get local coord system - tangent, normal, binormal, if possible
# get a local coord system (tangent, normal, binormal) at parameter offset (normally length)
t = edge.tangentAt(getParameterFromV0(edge, offset))
t.normalize()
try:
if normal:
n = normal
else:
n = edge.normalAt(getParameterFromV0(edge, offset))
n.normalize()
n = edge.normalAt(getParameterFromV0(edge, offset))
n.normalize()
b = (t.cross(n))
b.normalize()
# no normal defined here
except FreeCAD.Base.FreeCADError:
n = nullv
b = nullv
FreeCAD.Console.PrintLog(
FreeCAD.Console.PrintMessage(
"Draft PathArray.orientShape - Cannot calculate Path normal.\n")
lnodes = z.cross(b)
try:
# Can't normalize null vector.
lnodes.normalize()
except:
# pathological cases:
pass
# 1) can't determine normal, don't align.
if n == nullv:
psi = 0.0
theta = 0.0
phi = 0.0
FreeCAD.Console.PrintWarning(
"Draft PathArray.orientShape - Path normal is Null. Cannot align.\n")
elif abs(b.dot(z)) == 1.0: # 2) binormal is || z
# align shape to tangent only
psi = math.degrees(DraftVecUtils.angle(x, t, z))
theta = 0.0
phi = 0.0
FreeCAD.Console.PrintWarning(
"Draft PathArray.orientShape - Gimbal lock. Infinite lnodes. Change Path or Base.\n")
else: # regular case
psi = math.degrees(DraftVecUtils.angle(x, lnodes, z))
theta = math.degrees(DraftVecUtils.angle(z, b, lnodes))
phi = math.degrees(DraftVecUtils.angle(lnodes, t, b))
rotations = [placement.Rotation]
if psi != 0.0:
rotations.insert(0, FreeCAD.Rotation(z, psi))
if theta != 0.0:
rotations.insert(0, FreeCAD.Rotation(lnodes, theta))
if phi != 0.0:
rotations.insert(0, FreeCAD.Rotation(b, phi))
if len(rotations) == 1:
finalRotation = rotations[0]
else:
finalRotation = functools.reduce(
lambda rot1, rot2: rot1.multiply(rot2), rotations)
placement.Rotation = finalRotation
priority = "ZXY" #the default. Doesn't seem to affect results.
newRot = FreeCAD.Rotation(t, n, b, priority);
newGRot = newRot.multiply(globalRotation)
placement.Rotation = newGRot
return placement
@@ -2891,10 +2845,13 @@ class _PathArray(_DraftLink):
obj.addProperty("App::PropertyInteger","Count","Draft",QT_TRANSLATE_NOOP("App::Property","Number of copies"))
obj.addProperty("App::PropertyVectorDistance","Xlate","Draft",QT_TRANSLATE_NOOP("App::Property","Optional translation vector"))
obj.addProperty("App::PropertyBool","Align","Draft",QT_TRANSLATE_NOOP("App::Property","Orientation of Base along path"))
obj.addProperty("App::PropertyVector","TangentVector","Draft",QT_TRANSLATE_NOOP("App::Property","Alignment of copies"))
obj.Count = 2
obj.PathSubs = []
obj.Xlate = FreeCAD.Vector(0,0,0)
obj.Align = False
obj.TangentVector = FreeCAD.Vector(1.0, 0.0, 0.0)
if self.use_link:
obj.addProperty("App::PropertyBool","ExpandArray","Draft",
@@ -2923,8 +2880,17 @@ class _PathArray(_DraftLink):
else:
FreeCAD.Console.PrintLog ("_PathArray.createGeometry: path " + obj.PathObj.Name + " has no edges\n")
return
base = calculatePlacementsOnPath(
obj.Base.Shape.Placement.Rotation,w,obj.Count,obj.Xlate,obj.Align)
if (hasattr(obj, "TangentVector")) and (obj.Align):
basePlacement = obj.Base.Shape.Placement
baseRotation = basePlacement.Rotation
stdX = FreeCAD.Vector(1.0, 0.0, 0.0)
preRotation = FreeCAD.Rotation(stdX, obj.TangentVector) #make rotation from X to TangentVector
netRotation = baseRotation.multiply(preRotation)
base = calculatePlacementsOnPath(
netRotation,w,obj.Count,obj.Xlate,obj.Align)
else:
base = calculatePlacementsOnPath(
obj.Base.Shape.Placement.Rotation,w,obj.Count,obj.Xlate,obj.Align)
return _DraftLink.buildShape(self,obj,pl,base)
def getWireFromSubs(self,obj):