replace cq_toplevel.py --export-svg with --export-png, which uses the same render pipeline as the interactive editor

Makefile

@@ -81,11 +81,11 @@ build/web-viewer/index.html: doc.in/index.html build/web-viewer/vtk.js build/web
 	mkdir -p build/web-viewer
 	cp $< $@
 
-%.svg: cq_toplevel.py src/*.py
+%.png: cq_toplevel.py src/*.py
 	mkdir -p "$(@D)"
-	./cq_toplevel.py --export-svg $@
+	./cq_toplevel.py --export-png $@
 
-doc: build/web-viewer/index.html build/images/pinephone_front.svg build/images/pinephone_back.svg build/images/pinephone_right.svg
+doc: build/web-viewer/index.html build/images/pinephone_case.png
 
 clean:
 	rm -rf build

cq_toplevel.py

@@ -20,29 +20,53 @@ import case
 import pinephone
 import ldtek_battery
 
+from cadquery.occ_impl.assembly import toVTK
+from cadquery.vis import _to_assy, _vtkRenderWindow
+from vtkmodules.vtkRenderingCore import vtkRenderWindow, vtkWindowToImageFilter
+from vtkmodules.vtkIOImage import vtkPNGWriter
+
+
 logger = logging.getLogger(__name__)
 
-def svg_export_options(view: str):
-    proj = (1, 1, 1)
-    if view == "front":
-        proj = (0.00, -0.05, 0.10)
-    elif view == "back":
-        proj = (0.00, -0.05, -0.10)
-    elif view == "right":
-        proj = (-0.10, 0.00, 0.00)
-    return dict(
-        width = 1024,
-        height = 1024,
-        marginLeft = 100,
-        marginTop = 10,
-        showAxes = False,
-        # projectionDir controls both the angle and the distance from the camera to the model
-        projectionDir = proj,
-        strokeWidth = 0.25,
-        strokeColor = (255, 0, 0),
-        hiddenColor = (0, 0, 255),
-        showHidden = True,
-    )
+def export_png_image(obj, file_: str):
+    # obj = obj.val().scale(2)
+    # obj = obj.transformed(offset=(0, 0, 0))
+    assy = _to_assy(obj)
+    # win = _vtkRenderWindow(assy)
+    renderer = toVTK(assy)
+    win = vtkRenderWindow()
+    # win.SetMultiSamples(16)
+    # win.SetSize(1024, 1024)
+    win.AddRenderer(renderer)
+    win.Render()
+    camera = renderer.GetActiveCamera()
+    camera.Roll(-35)
+    camera.Elevation(-45)
+    # 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,
+    # else it'll adjust the camera based on the wrong aspect ratio.
+    renderer.ResetCamera()
+    renderer.SetBackground(0.8, 0.8, 0.8)
+
+    # win.SetPosition(-10, 0)
+
+    win.Render()
+
+    # documented here: <https://examples.vtk.org/site/Python/IO/ImageWriter/>
+    win_to_input = vtkWindowToImageFilter()
+    win_to_input.SetInput(win)
+    # win_to_input.SetScale(5)
+    # win_to_input.SetViewport(0, 0, 5, 5)
+    win_to_input.SetInputBufferTypeToRGB()
+    win_to_input.ReadFrontBufferOff()
+    win_to_input.Update()
+
+    exporter = vtkPNGWriter()
+    exporter.SetFileName(file_)
+    exporter.SetInputConnection(win_to_input.GetOutputPort())
+    exporter.Write()
+
 
 def _model():
     logger.info("computing model ...")
@@ -73,7 +97,7 @@ def main():
     parser.add_argument("--render-phone", action="store_true", help="render the case and also the phone within it; useful to confirm fit visually before printing")
     parser.add_argument("--render-phone-only", action="store_true", help="render *only* the phone, not even the case")
     parser.add_argument("--export-stl")
-    parser.add_argument("--export-svg")
+    parser.add_argument("--export-png")
     parser.add_argument("--export-vtk")
     parser.add_argument("--editor", action="store_true", help="view in cq-editor")
 
@@ -86,26 +110,22 @@ def main():
         os.environ["CASE_RENDER_PHONE_ONLY"] = "1"
 
     if args.export_stl:
+        model_ = model()
         logger.info("exporting stl to %s", args.export_stl)
-        cq.exporters.export(model(), args.export_stl)
+        cq.exporters.export(model_, args.export_stl)
 
-    if args.export_svg:
-        view = None
-        if "front" in args.export_svg:
-            view = "front"
-        elif "back" in args.export_svg:
-            view = "back"
-        elif "right" in args.export_svg:
-            view = "right"
-        logger.info("exporting svg to %s (view: %s)", args.export_svg, str(view))
-        cq.exporters.export(model(), args.export_svg, opt=svg_export_options(view))
+    if args.export_png:
+        model_ = model()
+        logger.info("exporting png to %s", args.export_png)
+        export_png_image(model_, args.export_png)
 
     if args.export_vtk:
         vtk_file = args.export_vtk
         js_var, _ext = os.path.splitext(os.path.basename(vtk_file))
         js_file = f'{vtk_file}.js'
+        model_ = model()
         logger.info("exporting VTK (for web rendering) to %s", vtk_file)
-        cq.exporters.export(model(), vtk_file, cq.exporters.ExportTypes.VTP)
+        cq.exporters.export(model_, vtk_file, cq.exporters.ExportTypes.VTP)
 
         logger.info("wrapping VTK data in a javascript variable (var %s) in %s", js_var, js_file)
         vtk_data = open(vtk_file).read()