BRepOffsetAPI_MakeThickSolid - Some characters canтще be hollowed out

from OCC.Core.Addons import text_to_brep, Font_FontAspect_Bold, Font_FA_Regular
from OCC.Core.BRepAdaptor import BRepAdaptor_Surface
from OCC.Core.TopExp import TopExp_Explorer
from OCC.Core.TopAbs import TopAbs_VERTEX, TopAbs_EDGE, TopAbs_FACE
from OCC.Core.GeomAbs import GeomAbs_Plane
from OCC.Display.backend import load_backend
from OCC.Core.TopTools import TopTools_ListOfShape
from OCC.Core.BRepOffsetAPI import BRepOffsetAPI_MakeThickSolid  #maketicksolidbysimple
from OCC.Display.OCCViewer import rgb_color
load_backend('qt-pyqt5')
from OCC.Core.gp import (gp_Pnt, gp_OX,gp_OY, gp_Vec, gp_Trsf, gp_DZ, gp_Ax2, gp_Ax3,
                         gp_Pnt2d, gp_Dir2d, gp_Ax2d, gp_Pln)
from OCC.Core.TopoDS import topods, TopoDS_Compound, TopoDS_Face
from OCC.Core.BRepPrimAPI import BRepPrimAPI_MakePrism, BRepPrimAPI_MakeCylinder,BRepPrimAPI_MakeBox
from OCC.Core.BRepBuilderAPI import BRepBuilderAPI_MakeFace, BRepBuilderAPI_Transform

from OCC.Core.BRep import BRep_Tool_Surface, BRep_Builder
from OCC.Core.Geom import Geom_Plane, Geom_CylindricalSurface

from OCC.Core.ShapeFix import ShapeFix_Shape,ShapeFix_Wireframe

def  build_zi_Shapefix():
    zi_hou = 10
    zihao = 30
    txt_Str = 'U'  #不可以DEFHIJKLMNT   QUVWXYZ   ，可以：0 ，ABCIQOPRSU
    txt_Str = 'H'  # 不可以DEFHIJKLMNT   QUVWXYZ   ，可以：0 ，ABCIQOPRSU
    txt_Font = 'Arial'
    aPrismVec = gp_Vec(0, 0, zi_hou)  # Vec face
    # D_Shape_Zi = text_to_brep(txt_Str, txt_Font, Font_FA_Regular, zihao, True)  #全部失败 #复合曲线是
    D_Shape_Zi = text_to_brep(txt_Str, txt_Font, Font_FA_Regular, zihao, False)  # 部分成功    复合曲线否fisCompositeCurve (bool)
    shape= BRepPrimAPI_MakePrism(D_Shape_Zi, aPrismVec).Shape()  # 形成字符模板TopoDS_Shape
    # display.DisplayShape(shape, update=True, color=rgb_color(0.5, 0.5, 0))  # 显示图 蓝
    def face_is_plane1(face):
        # 如果是平面，则返回True
        hs = BRep_Tool_Surface(face)
        downcast_result = Geom_Plane.DownCast(hs)
        if downcast_result is None:
            return False
        else:
            return True
    def surface_plane_from_face(aFace):
        """
        Returns the geometric plane entity from a planar surface
        """
        return Geom_Plane.DownCast(BRep_Tool_Surface(aFace))

    def scoop(shape, thickness):
        faceToRemove = None
        zMax = 1
        aFaceExplorer = TopExp_Explorer(shape, TopAbs_FACE)
        while aFaceExplorer.More():
            aFace = topods.Face(aFaceExplorer.Current())
            if face_is_plane1(aFace):
                aPlane = surface_plane_from_face(aFace)
                aPnt = aPlane.Location()
                aZ = aPnt.Z()
                # aZ = aPnt.Y()
                if aZ > zMax:# aZ < zMax---他砍掉了侧面:
                    zMax = aZ
                    faceToRemove = aFace
            aFaceExplorer.Next()

        facesToRemove = TopTools_ListOfShape()
        facesToRemove.Append(faceToRemove)

        shapeFixer = ShapeFix_Shape()
        shapeFixer.Init(shape)
        shapeFixer.SetPrecision(1)  # 精度
        shapeFixer.MaxTolerance()  # 最大允许公差 Prec# 1e-4
        shapeFixer.Perform()
        shape = shapeFixer.Shape()
        # display.DisplayShape(shape, update=True)  # 显示图 蓝
        # 第一个参数是shape，第二个是要删除的面的集合，第三个是变化后的厚度，第四个是偏差
        scoopShape = BRepOffsetAPI_MakeThickSolid(shape, facesToRemove, thickness, 0.001)
        # 1 S(TopoDS_Shape &) –
        # 2 ClosingFaces(TopTools_ListOfShape &) –
        # 3 Offset(float) –
        # 4 Tol(float) –
        # 5 Mode(BRepOffset_Mode) – default
        # 6 value is BRepOffset_Skin
        # 7 Intersection(bool) – default
        # 8 value is Standard_False
        # 9 SelfInter(bool) – default
        # 10 value is Standard_False
        # 11 Join(GeomAbs_JoinType) – default
        # 12 value is GeomAbs_Arc

        # BRepBuilderAPI.BRepBuilderAPI_MakeShape_Shape
        # step_writer.SetTolerance(1e-4)
        return scoopShape

    #挖空
    shape=scoop(shape, 1).Shape()

    # shapeFixer1 = ShapeFix_Shape()
    # shapeFixer1.Init(shape)
    # shapeFixer1.SetPrecision(1e-04)  # 精度
    # shapeFixer1.MaxTolerance()  # 最大允许公差 Prec#
    # shapeFixer1.Perform()
    # shape = shapeFixer1.Shape()

    # ShapeFix_FixSmallSolid_1=ShapeFix_Solid(shape)
    # ShapeFix_FixSmallSolid_1.Init(shape)
    # ShapeFix_FixSmallSolid_1.SetPrecision(1e-04)  # 精度
    # ShapeFix_FixSmallSolid_1.MaxTolerance()  # 最大允许公差 Prec#
    # ShapeFix_FixSmallSolid_1.Perform()
    # shape = ShapeFix_FixSmallSolid_1.FixShape()

    display.DisplayShape(shape, update=True, color=rgb_color(1, 1, 0.1))  # 显示图 蓝

if __name__ == "__main__":

    from OCC.Display.SimpleGui import init_display

    display, start_display, add_menu, add_function_to_menu = init_display()
    display.display_triedron()  # 坐標顯示
    display.set_bg_gradient_color([206, 215, 222], [0, 128, 0])  # 设置背景渐变色
    add_menu('管件字挖空管理')

    add_function_to_menu('管件字挖空管理',build_zi_Shapefix)

    start_display()