据我所知，没有内置的PyQt 3D绘制小部件/功能，因为您只能绘制2D多边形。但我们可以创建一个自定义类来模拟3D绘画。从您的Java链接reference：

Java支持3D矩形，但第三维的效果不是很明显。由于海拔较低，效果可以忽略不计。 Java设计师通过沿矩形边框绘制更亮和更暗的线条来实现3D效果。

我们可以模拟Java的3D绘图功能的效果：

void fill3DRect(int x, int y, int width, int height, boolean raised)

此方法使用上面指定的参数绘制实心3D矩形。最后一个布尔参数true表示高于绘图表面的高程，false表示蚀刻到表面。

为了在Python中获得3D效果，我们基本上可以通过使用两种颜色的颜色然后变暗并照亮某些边来做同样的事情。

from PyQt5 import QtCore, QtGui, QtWidgets

import sys

class Rectangle3D(QtWidgets.QWidget):

def __init__(self, parent=None):

QtWidgets.QWidget.__init__(self, parent)

# Elevated 3D rectangle color settings

self.elevated_border_color = QtGui.QColor(111,211,111)

self.elevated_fill_color = QtGui.QColor(0,255,0)

self.elevated_pen_width = 2.5

# Lowered 3D rectangle color settings

self.lowered_border_color = QtGui.QColor(0,235,0)

self.lowered_fill_color = QtGui.QColor(0,178,0)

self.lowered_pen_width = 2.5

def draw3DRectangle(self, x, y, w, h, raised=True):

# Specify the border/fill colors depending on raised or lowered

if raised:

# Line color (border)

self.pen = QtGui.QPen(self.elevated_border_color, self.elevated_pen_width)

# Fill color

self.fill = QtGui.QBrush(self.elevated_fill_color)

else:

# Line color (border)

self.pen = QtGui.QPen(self.lowered_border_color, self.lowered_pen_width)

# Fill color

self.fill = QtGui.QBrush(self.lowered_fill_color)

painter = QtGui.QPainter(self)

# Draw border color of rectangle

painter.setPen(self.pen)

painter.setBrush(self.fill)

painter.drawRect(x, y, w, h)

# Cover up the top and left sides with filled color using lines

if raised:

painter.setPen(QtGui.QPen(self.elevated_fill_color, self.elevated_pen_width))

else:

painter.setPen(QtGui.QPen(self.lowered_fill_color, self.lowered_pen_width))

painter.drawLine(x, y, x + w, y)

painter.drawLine(x, y, x, y + h)

def paintEvent(self, event):

self.draw3DRectangle(50,50,300,150,True)

self.draw3DRectangle(50,250,300,150,False)

if __name__ == '__main__':

app = QtWidgets.QApplication(sys.argv)

widget = Rectangle3D()

widget.show()

sys.exit(app.exec_())