Animate smooth transition between viewpoints with ViewProjection -> "Orthographic"

Question

I'm looking for code to animate smooth transition between 2 viewpoints with ViewProjection -> "Orthographic". My first attempt is below but it's missing some scale invariance.

• Where should I set PlotRange? Currently the only object that sets PlotRange is graph, but this setting seems to get lost in the pipeline

• How do I enforce AspectRatio to be 1?

th = Thickness[0.0015];
arrows = Graphics3D[{Arrowheads[0.02], th, 
    Arrow[{{1, 0, 0}, {-1, 0, 0}}], Arrow[{{0, 0, -1}, {0, 0, 1}}], 
    Arrow[{{0, 1, 0}, {0, -1, 0}}]}];
plane = Plot3D[0, {x, -1, 1}, {y, -1, 1}, PlotStyle -> None, 
   Mesh -> 5, MeshStyle -> Directive[Thickness[.001], Opacity[.2]], 
   BoundaryStyle -> Directive[th, Opacity[.2]]];
graph = Plot3D[{2/([Pi] Sqrt[(1 + x - y) (1 - x + y)]), 0}/
    10, {x, -1, 1}, {y, -1, 1}, 
   RegionFunction -> 
    Function[{x, y}, 0.9 <= x + y <= 1 && -1 <= x - y <= 1], 
   PlotRange -> {{-1, 1}, {-1, 1}, {0, .5}}, Filling -> 0, 
   FillingStyle -> Yellow, Mesh -> None, PlotPoints -> 50, 
   BoundaryStyle -> th, AspectRatio -> 1, Axes -> None, 
   Boxed -> False];
graphic3d = Show[arrows, plane, graph];
animateTransition[object_, t_, point1_, point2_] := Module[{},
   angle = t*[Pi]/2;
   Show[graph, arrows, plane, 
    ViewPoint -> point1Cos[angle] + point2Sin[angle], 
    ViewProjection -> "Orthographic"]
   ];
(* to get initial direction use 

https://mathematica.stackexchange.com/questions/132228/how-to-obtain-

the-viewpoint/132231 *)
startDirection = {1.17091, -2.65552, 1.73988}; 
endDirection = {-1, -1, 0};
pics = Table[
   animateTransition[graphic3d, t, startDirection, endDirection], {t, 
    0, 1, .1}];
ListAnimate[pics]