Python (COIN3D)箭头绘制不旋转(FreeCAD - pivy.coin )

Question

在我看来，下面的代码是正确的。但不幸的是我不能旋转箭头。无论我从什么角度给这个函数，它都不起作用。我不知道这段代码出了什么问题。

注意:这是我为FreeCAD构建的COIN3D小部件系统的一部分。你可以在我的github = https://github.com/MariwanJ/Design456/tree/devbranch上找到整个项目

#draw an arrow 
def draw_arrow(_Points=[], _color=(0,1,0), _ArrSize=1.0,_rotation=(1.0,1.0,1.0,0.0) ):
    print("point,arrsize,rota",_Points,_ArrSize,_rotation)
    if len (_Points)!=2:
        raise ValueError('must be 2 points')
    try:
        so_separatorRoot=coin.SoSeparator()
        so_separatorHead = coin.SoSeparator()
        so_separatorTail = coin.SoSeparator()
        
        transHead = coin.SoTranslation()   # decide at which position the object will be placed
        transTail = coin.SoTranslation()   # decide at which position the object will be placed
        transRoot= coin.SoTranslation()    # decide at which position the whole objects will be placed
        
        coordsRoot = coin.SoTransform()
        
        cone=coin.SoCone()
        cone.bottomRadius= 3
        cone.height= 3
        
        cylinder=coin.SoCylinder()
        cylinder.height = 10
        cylinder.radius = 0.5
        p1=_Points[0]
        p2=App.Vector(p1.x,p1.y-5,p1.z)

        styleHead = coin.SoDrawStyle()
        styleTail = coin.SoDrawStyle()
        
        styleHead.style = coin.SoDrawStyle.LINES     #draw only frame not filled
        styleHead.lineWidth = 3

        styleTail.style = coin.SoDrawStyle.LINES     #draw only frame not filled
        styleTail.lineWidth = 2
        
        coordsRoot.scaleFactor.setValue([_ArrSize,_ArrSize,_ArrSize])
        coordsRoot.translation.setValue(App.Vector(0,0,0))
        coordsRoot.rotation.Q=_rotation #  SbRotation (const SbVec3f &axis, const float radians)

        transHead.translation.setValue(p1)
        transTail.translation.setValue(p2)
        transRoot.translation.setValue(App.Vector(0.0,0.0,0.0))
        
        color=coin.SoBaseColor(); 
        color.rgb=_color
        
        so_separatorHead.addChild(color)
        so_separatorTail.addChild(color)
        
        so_separatorHead.addChild(transHead)
        so_separatorTail.addChild(transTail)

        so_separatorHead.addChild(styleHead)
        so_separatorHead.addChild(cone)
        
        so_separatorTail.addChild(styleTail)
        so_separatorTail.addChild(cylinder)
        
        so_separatorRoot.addChild(transRoot)
        so_separatorRoot.addChild(color)
        so_separatorRoot.addChild(coordsRoot)
        so_separatorRoot.addChild(so_separatorHead)
        so_separatorRoot.addChild(so_separatorTail)
        
        return so_separatorRoot

    except Exception as err:
        App.Console.PrintError("'Design456_DirectScale' Failed. "
                               "{err}\n".format(err=str(err)))
        exc_type, exc_obj, exc_tb = sys.exc_info()
        fname = os.path.split(exc_tb.tb_frame.f_code.co_filename)[1]
        print(exc_type, fname, exc_tb.tb_lineno)

Answer 1

我找到了解决方案。事实上，我已经在问题中找到了答案。看看这一行：coordsRoot.rotation.Q=_rotation # SbRotation (const SbVec3f &axis, const float radians)

这里提到你必须给出四个浮点值。是我的错。但是Python的问题是..它不会产生任何错误。这让我的故障排除变得太困难了。没有(.Q)作为该对象(SbRotation)的子对象。我写下了正确的代码，以防其他人想使用它。

def draw_arrow(_Points=[], _color=FR_COLOR.FR_OLIVE, _ArrSize=1.0,_rotation=(1.0,1.0,1.0,0.0)):
    '''
    Draw a 3D arrow at the position given by the _Points and the color given by _color. 
    Scale it by the _ArrSize, and rotate it by the _rotation which consist of four float values(x,y,z ,and Angel), angle in radians. 
    '''
    if len (_Points)!=2:
        raise ValueError('Vertices must be 2')
    try:
        so_separatorRoot=coin.SoSeparator()
        so_separatorHead = coin.SoSeparator()
        so_separatorTail = coin.SoSeparator()
        
        transHead = coin.SoTranslation()   # decide at which position the object will be placed
        transTail = coin.SoTranslation()   # decide at which position the object will be placed
        transRoot= coin.SoTranslation()    # decide at which position the whole objects will be placed
        
        coordsRoot = coin.SoTransform()
        
        cone=coin.SoCone()
        cone.bottomRadius= 3
        cone.height= 3
        
        cylinder=coin.SoCylinder()
        cylinder.height = 10
        cylinder.radius = 0.5
        p1=_Points[0]
        p2=App.Vector(p1.x,p1.y-5,p1.z)

        styleHead = coin.SoDrawStyle()
        styleTail = coin.SoDrawStyle()
        
        styleHead.style = coin.SoDrawStyle.LINES     #draw only frame not filled
        styleHead.lineWidth = 3

        styleTail.style = coin.SoDrawStyle.LINES     #draw only frame not filled
        styleTail.lineWidth = 2
        
        coordsRoot.scaleFactor.setValue([_ArrSize,_ArrSize,_ArrSize])
        coordsRoot.translation.setValue(App.Vector(0,0,0))
        coordsRoot.rotation.setValue(_rotation) #  SbRotation (const SbVec3f &axis, const float radians)
        

        transHead.translation.setValue(p1)
        transTail.translation.setValue(p2)
        transRoot.translation.setValue(App.Vector(0.0,0.0,0.0))
        
        color=coin.SoBaseColor(); 
        color.rgb=_color
        
        so_separatorHead.addChild(color)
        so_separatorTail.addChild(color)
        
        so_separatorHead.addChild(transHead)
        so_separatorTail.addChild(transTail)

        so_separatorHead.addChild(styleHead)
        so_separatorHead.addChild(cone)
        
        so_separatorTail.addChild(styleTail)
        so_separatorTail.addChild(cylinder)

        print("rotatin",_rotation)
        so_separatorRoot.addChild(coordsRoot)       
        so_separatorRoot.addChild(transRoot)
        so_separatorRoot.addChild(so_separatorHead)
        so_separatorRoot.addChild(so_separatorTail)

        
        return so_separatorRoot
        # we have a selected object. Try to show the dimensions. 
        
    except Exception as err:
        App.Console.PrintError("'Design456_DirectScale' Failed. "
                               "{err}\n".format(err=str(err)))
        exc_type, exc_obj, exc_tb = sys.exc_info()
        fname = os.path.split(exc_tb.tb_frame.f_code.co_filename)[1]
        print(exc_type, fname, exc_tb.tb_lineno)