cq_toplevel: allow exporting case in front/back/side orientation

cq_toplevel.py

@@ -28,15 +28,22 @@ from vtkmodules.vtkIOImage import vtkPNGWriter
 
 logger = logging.getLogger(__name__)
 
-def export_png_image(obj, file_: str):
+def export_png_image(obj, file_: str, orientation: str):
     assy = _to_assy(obj)
     renderer = toVTK(assy)
     win = vtkRenderWindow()
     win.AddRenderer(renderer)
     win.Render()
     camera = renderer.GetActiveCamera()
-    camera.Roll(-35)
-    camera.Elevation(-45)
+    if orientation == "front":
+        camera.Roll(-28)
+        camera.Elevation(-50)
+    elif orientation == "back":
+        camera.Roll(0)
+        camera.Elevation(-35)
+    elif orientation == "side":
+        camera.Yaw(75)
+        camera.Elevation(30)
     # adjust camera so full object is visible.
     # this also resizes the window, potentially changing its aspect ratio.
     # it's important that the window has been `Render()`'d at least once by now,
@@ -106,9 +113,16 @@ def main():
         cq.exporters.export(model_, args.export_stl)
 
     if args.export_png:
+        orientation = None
+        if "side" in args.export_png:
+            orientation = "side"
+        if "back" in args.export_png:
+            orientation = "back"
+        if "front" in args.export_png:
+            orientation = "front"
         model_ = model()
         logger.info("exporting png to %s", args.export_png)
-        export_png_image(model_, args.export_png)
+        export_png_image(model_, args.export_png, orientation)
 
     if args.export_vtk:
         vtk_file = args.export_vtk