STEP export

* exporters.export: expose STEP options
* Use default OCCT write.precision.mode value 0
* Doc update

Merge branch 'master' into step

Author: lorenzncode

cadquery/assembly.py

@@ -357,13 +357,16 @@ def solve(self) -> "Assembly":
         ents = {}
 
         i = 0
-        locked = []
+        locked: List[int] = []
+
         for c in self.constraints:
             for name in c.objects:
                 if name not in ents:
                     ents[name] = i
                     i += 1
-                if c.kind == "Fixed" or name == self.name:
+                if (c.kind == "Fixed" or name == self.name) and ents[
+                    name
+                ] not in locked:
                     locked.append(ents[name])
 
         # Lock the first occuring entity if needed.
@@ -402,15 +405,32 @@ def solve(self) -> "Assembly":
         if not constraints:
             raise ValueError("At least one constraint required")
 
+        # check if at least two entities are present
+        if len(ents) < 2:
+            raise ValueError("At least two entities need to be constrained")
+
         # instantiate the solver
-        solver = ConstraintSolver(locs, constraints, locked=locked)
+        scale = self.toCompound().BoundingBox().DiagonalLength
+        solver = ConstraintSolver(locs, constraints, locked=locked, scale=scale)
 
         # solve
         locs_new, self._solve_result = solver.solve()
 
         # update positions
+
+        # find the inverse root loc
+        loc_root_inv = Location()
+
+        if self.obj:
+            for loc_new, n in zip(locs_new, ents):
+                if n == self.name:
+                    loc_root_inv = loc_new.inverse
+                    break
+
+        # update the positions
         for loc_new, n in zip(locs_new, ents):
-            self.objects[n].loc = loc_new
+            if n != self.name:
+                self.objects[n].loc = loc_root_inv * loc_new
 
         return self
 
@@ -423,12 +443,14 @@ def save(
         **kwargs,
     ) -> "Assembly":
         """
-        save as STEP or OCCT native XML file
+        Save assembly to a file.
 
-        :param path: filepath
+        :param path: Path and filename for writing.
         :param exportType: export format (default: None, results in format being inferred form the path)
         :param tolerance: the deflection tolerance, in model units. Only used for GLTF, VRML. Default 0.1.
         :param angularTolerance: the angular tolerance, in radians. Only used for GLTF, VRML. Default 0.1.
+        :param **kwargs: Additional keyword arguments.  Only used for STEP.
+            See :meth:`~cadquery.occ_impl.exporters.assembly.exportAssembly`.
         """
 
         if exportType is None:

cadquery/occ_impl/exporters/__init__.py

@@ -100,7 +100,10 @@ def export(
             raise ValueError("Only Workplanes can be exported as DXF")
 
     elif exportType == ExportTypes.STEP:
-        shape.exportStep(fname)
+        if opt:
+            shape.exportStep(fname, **opt)
+        else:
+            shape.exportStep(fname)
 
     elif exportType == ExportTypes.STL:
         shape.exportStl(fname, tolerance, angularTolerance)

cadquery/occ_impl/exporters/assembly.py

@@ -28,31 +28,26 @@
 
 def exportAssembly(assy: AssemblyProtocol, path: str, **kwargs) -> bool:
     """
-    Export an assembly to a step a file.
+    Export an assembly to a STEP file.
 
     kwargs is used to provide optional keyword arguments to configure the exporter.
-    The current parameters are as follows:
 
-    :param write_pcurves: Enables or disables P-Curve entities written to STEP file
+    :param assy: assembly
+    :param path: Path and filename for writing
+    :param write_pcurves: Enable or disable writing parametric curves to the STEP file. Default True.
+
+        If False, writes STEP file without pcurves. This decreases the size of the resulting STEP file.
     :type write_pcurves: boolean
-    :param precision_mode: Sets the precision mode of the OCCT STEP exporter
+    :param precision_mode: Controls the uncertainty value for STEP entities. Specify -1, 0, or 1. Default 0.
+        See OCCT documentation.
     :type precision_mode: int
-
-    The default behaviour of the OCCT STEP file writer is to add redundant
-    P-Curve entities to the STEP file.  This can often double the size of the
-    resulting STEP file.  Turning off P-Curves can save file size and almost
-    never impacts the quality of the STEP file.
-
-    The precision mode parameter coresponds to the OCCT STEP file precision
-    for writing geometric data.  The default value of 1 for maximum precision
-    is used by can be changed if desired.
     """
 
     # Handle the extra settings for the STEP export
     pcurves = 1
     if "write_pcurves" in kwargs and not kwargs["write_pcurves"]:
         pcurves = 0
-    precision_mode = kwargs["precision_mode"] if "precision_mode" in kwargs else 1
+    precision_mode = kwargs["precision_mode"] if "precision_mode" in kwargs else 0
 
     _, doc = toCAF(assy, True)
 

cadquery/occ_impl/geom.py

@@ -790,6 +790,9 @@ class BoundBox(object):
     zmax: float
     zlen: float
 
+    center: Vector
+    DiagonalLength: float
+
     def __init__(self, bb: Bnd_Box) -> None:
         self.wrapped = bb
         XMin, YMin, ZMin, XMax, YMax, ZMax = bb.Get()

cadquery/occ_impl/shapes.py

@@ -453,31 +453,25 @@ def exportStl(
 
     def exportStep(self, fileName: str, **kwargs) -> IFSelect_ReturnStatus:
         """
-        Export this shape to a STEP file
+        Export this shape to a STEP file.
 
         kwargs is used to provide optional keyword arguments to configure the exporter.
-        The current parameters are as follows:
 
-        :param write_pcurves: Enables or disables P-Curve entities written to STEP file
+        :param fileName: Path and filename for writing.
+        :param write_pcurves: Enable or disable writing parametric curves to the STEP file. Default True.
+
+            If False, writes STEP file without pcurves. This decreases the size of the resulting STEP file.
         :type write_pcurves: boolean
-        :param precision_mode: Sets the precision mode of the OCCT STEP exporter
+        :param precision_mode: Controls the uncertainty value for STEP entities. Specify -1, 0, or 1. Default 0.
+            See OCCT documentation.
         :type precision_mode: int
-
-        The default behaviour of the OCCT STEP file writer is to add redundant
-        P-Curve entities to the STEP file.  This can often double the size of the
-        resulting STEP file.  Turning off P-Curves can save file size and almost
-        never impacts the quality of the STEP file.
-
-        The precision mode parameter coresponds to the OCCT STEP file precision
-        for writing geometric data.  The default value of 1 for maximum precision
-        is used by can be changed if desired.
         """
 
         # Handle the extra settings for the STEP export
         pcurves = 1
         if "write_pcurves" in kwargs and not kwargs["write_pcurves"]:
             pcurves = 0
-        precision_mode = kwargs["precision_mode"] if "precision_mode" in kwargs else 1
+        precision_mode = kwargs["precision_mode"] if "precision_mode" in kwargs else 0
 
         writer = STEPControl_Writer()
         Interface_Static.SetIVal_s("write.surfacecurve.mode", pcurves)