应该用纹理，这里没有去找相应的，暂时可以用用 Mathematica 12.1 提供的各种 Shading。而且为了效果好，应该独立画出各个曲面片而不是用 RegionPlot3D ，也不需要用 RegionFunction 写不等式，用 MeshFunction 和 MeshShading 。
SetOptions[ContourPlot3D, Boxed -> False, Axes -> False,
Lighting -> Automatic, BoundaryStyle -> None,
Mesh -> {{0}, {0}, {0}}];
f1 = x^2 + y^2 + z^2 - 1;
f2 = x^2 + y^2 + z^2 - 2^2;
f3 = x;
f4 = y;
f5 = z;
pureFun[f_] := (Evaluate[
f /. {x -> Slot@1, y -> Slot@2, z -> Slot@3}]) &;
s1 = ContourPlot3D[f1 == 0, {x, -1, 1}, {y, -1, 1}, {z, -1, 1},
MeshFunctions -> pureFun /@ {f3, f4, f5},
MeshShading -> {{{None, None}, {None, None}}, {{None,
StippleShading[0.9]}, {None, None}}}, MeshStyle -> None];
s2 = ContourPlot3D[f2 == 0, {x, -2, 2}, {y, -2, 2}, {z, -2, 2},
MeshFunctions -> pureFun /@ {f3, f4, f5},
MeshShading -> {{{HatchShading[], HatchShading[]}, {HatchShading[],
HatchShading[]}}, {{HatchShading[], None}, {HatchShading[],
HatchShading[]}}}, MeshStyle -> None];
s3 = ContourPlot3D[f3 == 0, {x, -2, 2}, {y, -2, 2}, {z, -2, 2},
MeshFunctions -> pureFun /@ {f1, f2, f4, f5},
MeshShading -> {{{{None, None}, {None, None}}, {{None,
None}, {None, None}}}, {{{None,
HalftoneShading[0.6, Orange]}, {None, None}}, {{None,
None}, {None, None}}}}, MeshStyle -> None];
s4 = ContourPlot3D[f4 == 0, {x, -2, 2}, {y, -2, 2}, {z, -2, 2},
MeshFunctions -> pureFun /@ {f1, f2, f3, f5},
MeshShading -> {{{{None, None}, {None, None}}, {{None,
None}, {None, None}}}, {{{None, None}, {None, None}}, {{None,
HalftoneShading[0.6, Orange]}, {None, None}}}},
MeshStyle -> None];
s5 = ContourPlot3D[f5 == 0, {x, -2, 2}, {y, -2, 2}, {z, -2, 2},
MeshFunctions -> pureFun /@ {f1, f2, f3, f4},
MeshShading -> {{{{None, None}, {None, None}}, {{None,
HalftoneShading[0.8, Orange]}, {None, None}}}, {{{None,
None}, {None, None}}, {{None, None}, {None, None}}}},
MeshStyle -> None];
Show[s1, s2, s3, s4, s5, PlotRange -> All]
