(Part 2/3) Project 3D part to plane

cadquery/func.py

@@ -59,6 +59,8 @@
     chamfer2D,
     draft,
     History,
+    HLRResult,
+    hlr,
 )
 
 __all__ = [
@@ -124,4 +126,6 @@
     "fillet2D",
     "draft",
     "History",
+    "HLRResult",
+    "hlr",
 ]

cadquery/occ_impl/exporters/__init__.py

@@ -1,21 +1,16 @@
-import tempfile
-import os
-import io as StringIO
-
 from typing import IO, Optional, Union, cast, Dict, Any, Iterable
 from typing_extensions import Literal
 
 from OCP.VrmlAPI import VrmlAPI
 
-from ...utils import deprecate
 from ..shapes import Shape, compound
 from ...types import UnitLiterals
 
-from .svg import getSVG
+from .svg import getSVG, exportSVG
 from .json import JsonMesh
 from .amf import AmfWriter
 from .threemf import ThreeMFWriter
-from .dxf import exportDXF, DxfDocument
+from .dxf import exportDXF, exportDXFProjection, DxfDocument
 from .vtk import exportVTP
 
 

cadquery/occ_impl/exporters/dxf.py

@@ -1,5 +1,6 @@
 """DXF export utilities."""
 
+from os import PathLike
 from typing import (
     Any,
     Dict,
@@ -22,8 +23,8 @@
 from typing_extensions import Self
 
 from ...units import RAD2DEG
-from ..shapes import Face, Edge, Shape, Compound, compound
-from ..geom import Plane
+from ..shapes import Face, Edge, Shape, Compound, compound, hlr
+from ..geom import Plane, VectorLike
 
 
 ApproxOptions = Literal["spline", "arc"]
@@ -157,6 +158,7 @@ def add_shape(self, shape: Union[WorkplaneLike, Shape], layer: str = "") -> Self
             plane = shape.plane
             shape_ = compound(*shape.__iter__()).transformShape(plane.fG)
         else:
+            plane = Plane((0, 0, 0))
             shape_ = shape
 
         general_attributes = {}
@@ -365,7 +367,7 @@ def _dxf_spline(cls, edge: Edge, plane: Plane) -> DxfEntityAttributes:
 
 
 def exportDXF(
-    w: Union[WorkplaneLike, Shape, Iterable[Shape]],
+    w: WorkplaneLike | Shape | Iterable[Shape],
     fname: str,
     approx: Optional[ApproxOptions] = None,
     tolerance: float = 1e-3,
@@ -394,3 +396,41 @@ def exportDXF(
 
     zoom.extents(dxf.msp)
     dxf.document.saveas(fname)
+
+
+def exportDXFProjection(
+    s: Union[WorkplaneLike, Shape],
+    path: PathLike | str,
+    dir: VectorLike,
+    pnt: VectorLike = (0, 0, 0),
+    approx: Optional[ApproxOptions] = None,
+    tolerance: float = 1e-3,
+    *,
+    up: Optional[VectorLike] = None,
+    doc_units: int = units.MM,
+) -> None:
+    """
+    Export to DXF using projections. Works with 3D objects.
+
+    :param s: Shape or Workplane to be exported.
+    :param path: Output file path.
+    :param dir: Direction of projection.
+    :param pnt: Origin of the projection plane.
+    :param up: Direction that should appear upward in the projected output. None
+        preserves OCCT's default in-plane orientation.
+    :param approx: Approximation strategy. None means no approximation is applied.
+        "spline" results in all splines being approximated as cubic splines. "arc" results
+        in all curves being approximated as arcs and straight segments.
+    :param tolerance: Approximation tolerance.
+    :param doc_units: ezdxf document/modelspace :doc:`units <ezdxf-stable:concepts/units>` (in. = ``1``, mm = ``4``).
+    """
+
+    shapes = []
+
+    if isinstance(s, WorkplaneLike):
+        for s in s.__iter__():
+            shapes.append(hlr(s, dir, pnt, up=up).visible)
+    else:
+        shapes.append(hlr(s, dir, pnt, up=up).visible)
+
+    exportDXF(shapes, str(path), approx, tolerance, doc_units=doc_units)

cadquery/occ_impl/exporters/svg.py

@@ -1,13 +1,10 @@
 import io as StringIO
 
-from ..shapes import Shape, Compound, TOLERANCE
+from ..shapes import Compound, Edge
 from ..geom import BoundBox
+from ..shapes import hlr
 
 
-from OCP.gp import gp_Ax2, gp_Pnt, gp_Dir
-from OCP.BRepLib import BRepLib
-from OCP.HLRBRep import HLRBRep_Algo, HLRBRep_HLRToShape
-from OCP.HLRAlgo import HLRAlgo_Projector
 from OCP.GCPnts import GCPnts_QuasiUniformDeflection
 
 DISCRETIZATION_TOLERANCE = 1e-3
@@ -106,21 +103,21 @@ def makeSVGedge(e):
     return cs.getvalue()
 
 
-def getPaths(visibleShapes, hiddenShapes):
+def getPaths(
+    visibleEdges: list[Edge], hiddenEdges: list[Edge]
+) -> tuple[list[str], list[str]]:
     """
     Collects the visible and hidden edges from the CadQuery object.
     """
 
     hiddenPaths = []
     visiblePaths = []
 
-    for s in visibleShapes:
-        for e in s.Edges():
-            visiblePaths.append(makeSVGedge(e))
+    for e in visibleEdges:
+        visiblePaths.append(makeSVGedge(e))
 
-    for s in hiddenShapes:
-        for e in s.Edges():
-            hiddenPaths.append(makeSVGedge(e))
+    for e in hiddenEdges:
+        hiddenPaths.append(makeSVGedge(e))
 
     return (hiddenPaths, visiblePaths)
 
@@ -138,8 +135,10 @@ def getSVG(shape, opts=None):
         marginLeft: Inset margin from the left side of the document.
         marginTop: Inset margin from the top side of the document.
         projectionDir: Direction the camera will view the shape from.
+        up: Direction that should appear upward in the projected output. None
+            preserves OCCT's default in-plane orientation.
         showAxes: Whether or not to show the axes indicator, which will only be
-                  visible when the projectionDir is also at the default.
+                  visible when projectionDir and up are also at the defaults.
         strokeWidth: Width of the line that visible edges are drawn with.
         strokeColor: Color of the line that visible edges are drawn with.
         hiddenColor: Color of the line that hidden edges are drawn with.
@@ -155,6 +154,7 @@ def getSVG(shape, opts=None):
         "marginLeft": 200,
         "marginTop": 20,
         "projectionDir": (-1.75, 1.1, 5),
+        "up": None,
         "showAxes": True,
         "strokeWidth": -1.0,  # -1 = calculated based on unitScale
         "strokeColor": (0, 0, 0),  # RGB 0-255
@@ -179,71 +179,26 @@ def getSVG(shape, opts=None):
     marginLeft = float(d["marginLeft"])
     marginTop = float(d["marginTop"])
     projectionDir = tuple(d["projectionDir"])
+    up = d["up"]
     showAxes = bool(d["showAxes"])
     strokeWidth = float(d["strokeWidth"])
     strokeColor = tuple(d["strokeColor"])
     hiddenColor = tuple(d["hiddenColor"])
     showHidden = bool(d["showHidden"])
     focus = float(d["focus"]) if d.get("focus") else None
 
-    hlr = HLRBRep_Algo()
-    hlr.Add(shape.wrapped)
-
-    coordinate_system = gp_Ax2(gp_Pnt(), gp_Dir(*projectionDir))
-
-    if focus is not None:
-        projector = HLRAlgo_Projector(coordinate_system, focus)
-    else:
-        projector = HLRAlgo_Projector(coordinate_system)
-
-    hlr.Projector(projector)
-    hlr.Update()
-    hlr.Hide()
-
-    hlr_shapes = HLRBRep_HLRToShape(hlr)
-
-    visible = []
-
-    visible_sharp_edges = hlr_shapes.VCompound()
-    if not visible_sharp_edges.IsNull():
-        visible.append(visible_sharp_edges)
-
-    visible_smooth_edges = hlr_shapes.Rg1LineVCompound()
-    if not visible_smooth_edges.IsNull():
-        visible.append(visible_smooth_edges)
-
-    visible_contour_edges = hlr_shapes.OutLineVCompound()
-    if not visible_contour_edges.IsNull():
-        visible.append(visible_contour_edges)
-
-    hidden = []
-
-    hidden_sharp_edges = hlr_shapes.HCompound()
-    if not hidden_sharp_edges.IsNull():
-        hidden.append(hidden_sharp_edges)
-
-    hidden_contour_edges = hlr_shapes.OutLineHCompound()
-    if not hidden_contour_edges.IsNull():
-        hidden.append(hidden_contour_edges)
-
-    # Fix the underlying geometry - otherwise we will get segfaults
-    for el in visible:
-        BRepLib.BuildCurves3d_s(el, TOLERANCE)
-    for el in hidden:
-        BRepLib.BuildCurves3d_s(el, TOLERANCE)
-
-    # convert to native CQ objects
-    visible = list(map(Shape, visible))
-    hidden = list(map(Shape, hidden))
-    (hiddenPaths, visiblePaths) = getPaths(visible, hidden)
+    hlr_result = hlr(shape, projectionDir, up=up, focus=focus)
+    visibleEdges = hlr_result.visible
+    hiddenEdges = hlr_result.hidden
+    hiddenPaths, visiblePaths = getPaths(visibleEdges, hiddenEdges)
 
     # get bounding box -- these are all in 2D space
-    bb = Compound.makeCompound(hidden + visible).BoundingBox()
+    bb = Compound.makeCompound(hiddenEdges + visibleEdges).BoundingBox()
 
     # Determine whether the user wants to fit the drawing to the bounding box
-    if width == None or height == None:
+    if width is None or height is None:
         # Fit image to specified width (or height)
-        if width == None:
+        if width is None:
             width = (height - (2.0 * marginTop)) * (
                 bb.xlen / bb.ylen
             ) + 2.0 * marginLeft
@@ -280,7 +235,7 @@ def getSVG(shape, opts=None):
         visibleContent += PATHTEMPLATE % p
 
     # If the caller wants the axes indicator and is using the default direction, add in the indicator
-    if showAxes and projectionDir == (-1.75, 1.1, 5):
+    if showAxes and projectionDir == (-1.75, 1.1, 5) and up is None:
         axesIndicator = AXES_TEMPLATE % (
             {"unitScale": str(unitScale), "textboxY": str(height - 30), "uom": str(uom)}
         )