Merge pull request #27 from mahgadalla/dev

Add method generate_iges inside Blade class

Author: mtezzele

.travis.yml

@@ -68,6 +68,11 @@ install:
       fi
     - source activate test
     - conda install --yes numpy scipy matplotlib pip nose sip=4.18
+    - if [[ "$TOXENV" == "py27" ]]; then
+        conda install --yes -c conda-forge -c dlr-sc -c pythonocc -c oce pythonocc-core=0.18.1 python=2.7;
+      else
+        conda install --yes -c conda-forge -c dlr-sc -c pythonocc -c oce pythonocc-core=0.18.1 python=3.6;
+      fi
     - pip install setuptools
     - pip install enum34
     - pip install coveralls

README.md

@@ -40,7 +40,13 @@
 See the [**Examples**](#examples) section below and the [**Tutorials**](tutorials/README.md) to have an idea of the potential of this package.
 
 ## Dependencies and installation
-**BladeX** requires requires `numpy`, `scipy`, `matplotlib`, and `sphinx` (for the documentation). The code is compatible with Python 2.7 and Python 3.6. It can be installed using `pip` or directly from the source code.
+**BladeX** requires `numpy`, `scipy`, `matplotlib`, `sphinx` (for the documentation), and `nose` (for the local test). They can be easily installed using `pip`. 
+**BladeX** is compatible with Python 2.7 and Python 3.6. Moreover, some of the modules require `OCC` to be installed for the `.iges` or `.stl` CAD generation. Please see the table below for instructions on how to satisfy the `OCC` requirements. You can also refer to `pythonocc.org` or `github.com/tpaviot/pythonocc-core` for further instructions.
+
+| Package | Version     | How to install (precompiled binaries via conda)                                                          |
+|---------|-------------|----------------------------------------------------------------------------------------------------------|
+| OCC     | ==0.18.1    | Python2.7 `conda install -c conda-forge -c dlr-sc -c pythonocc -c oce pythonocc-core==0.18.1 python=2.7` |
+| OCC     | ==0.18.1    | Python3.6 `conda install -c conda-forge -c dlr-sc -c pythonocc -c oce pythonocc-core==0.18.1 python=3.6` |
 
 
 ### Installing from source

bladex/blade.py

@@ -344,9 +344,275 @@ def plot(self, elev=None, azim=None, outfile=None):
         if outfile:
             plt.savefig(outfile)
 
+    def generate_iges(self,
+                      upper_face=None,
+                      lower_face=None,
+                      tip=None,
+                      display=False,
+                      errors=None):
+        """
+        Generate and export the .iges CAD for the blade upper face, lower face,
+        and tip. This method requires PythonOCC to be installed.
+
+        :param string upper_face: if string is passed then the method generates
+            the blade upper surface using the BRepOffsetAPI_ThruSections
+            algorithm, then exports the generated CAD into .iges file holding
+            the name <upper_face_string>.iges. Default value is None
+        :param string lower_face: if string is passed then the method generates
+            the blade lower surface using the BRepOffsetAPI_ThruSections
+            algorithm, then exports the generated CAD into .iges file holding
+            the name <lower_face_string>.iges. Default value is None
+        :param string tip: if string is passed then the method generates
+            the blade tip using the BRepOffsetAPI_ThruSections algorithm
+            in order to close the blade, then exports the generated CAD into
+            .iges file holding the name <tip_string>.iges. Default value is None
+        :param bool display: if True, then display the generated CAD. Default
+            value is False
+        :param string errors: if string is passed then the method writes out
+            the distances between each discrete point used to construct the
+            blade and the nearest point on the CAD that is perpendicular to
+            that point. Default value is None
+
+        We note that the blade object must have its radial sections be arranged
+        in order from the blade root to the blade tip, so that generate_iges
+        method can build the CAD surface that passes through the corresponding
+        airfoils. Also to be able to identify and close the blade tip.
+        """
+
+        from OCC.BRepBuilderAPI import BRepBuilderAPI_MakeEdge,\
+             BRepBuilderAPI_MakeWire, BRepBuilderAPI_MakeVertex
+        from OCC.Display.SimpleGui import init_display
+        from OCC.gp import gp_Pnt
+        from OCC.TColgp import TColgp_HArray1OfPnt
+        from OCC.GeomAPI import GeomAPI_Interpolate
+        from OCC.IGESControl import IGESControl_Writer
+        from OCC.BRepOffsetAPI import BRepOffsetAPI_ThruSections
+        from OCC.BRepExtrema import BRepExtrema_DistShapeShape
+
+        if upper_face:
+            self._check_string(filename=upper_face)
+            # Initializes ThruSections algorithm for building a shell passing
+            # through a set of sections (wires). The generated faces between
+            # the edges of every two consecutive wires are smoothed out with
+            # a precision criterion = 1e-10
+            generator = BRepOffsetAPI_ThruSections(False, False, 1e-10)
+            # Define upper edges (wires) for the face generation
+            for i in range(self.n_sections):
+                npoints = len(self.blade_coordinates_up[i][0])
+                vertices = TColgp_HArray1OfPnt(1, npoints)
+                for j in range(npoints):
+                    vertices.SetValue(
+                        j + 1,
+                        gp_Pnt(1000 * self.blade_coordinates_up[i][0][j],
+                               1000 * self.blade_coordinates_up[i][1][j],
+                               1000 * self.blade_coordinates_up[i][2][j]))
+                # Initializes an algorithm for constructing a constrained
+                # BSpline curve passing through the points of the blade i-th
+                # section, with tolerance = 1e-9
+                bspline = GeomAPI_Interpolate(vertices.GetHandle(), False, 1e-9)
+                bspline.Perform()
+                edge = BRepBuilderAPI_MakeEdge(bspline.Curve()).Edge()
+                if i == 0:
+                    bound_root_edge = edge
+                # Add BSpline wire to the generator constructor
+                generator.AddWire(BRepBuilderAPI_MakeWire(edge).Wire())
+            # Returns the shape built by the shape construction algorithm
+            generator.Build()
+            # Returns the Face generated by each edge of the first section
+            generated_upper_face = generator.GeneratedFace(bound_root_edge)
+
+            # Write IGES
+            iges_writer = IGESControl_Writer()
+            iges_writer.AddShape(generated_upper_face)
+            iges_writer.Write(upper_face + '.iges')
+
+        if lower_face:
+            self._check_string(filename=lower_face)
+            # Initializes ThruSections algorithm for building a shell passing
+            # through a set of sections (wires). The generated faces between
+            # the edges of every two consecutive wires are smoothed out with
+            # a precision criterion = 1e-10
+            generator = BRepOffsetAPI_ThruSections(False, False, 1e-10)
+            # Define upper edges (wires) for the face generation
+            for i in range(self.n_sections):
+                npoints = len(self.blade_coordinates_down[i][0])
+                vertices = TColgp_HArray1OfPnt(1, npoints)
+                for j in range(npoints):
+                    vertices.SetValue(
+                        j + 1,
+                        gp_Pnt(1000 * self.blade_coordinates_down[i][0][j],
+                               1000 * self.blade_coordinates_down[i][1][j],
+                               1000 * self.blade_coordinates_down[i][2][j]))
+                # Initializes an algorithm for constructing a constrained
+                # BSpline curve passing through the points of the blade i-th
+                # section, with tolerance = 1e-9
+                bspline = GeomAPI_Interpolate(vertices.GetHandle(), False, 1e-9)
+                bspline.Perform()
+                edge = BRepBuilderAPI_MakeEdge(bspline.Curve()).Edge()
+                if i == 0:
+                    bound_root_edge = edge
+                # Add BSpline wire to the generator constructor
+                generator.AddWire(BRepBuilderAPI_MakeWire(edge).Wire())
+            # Returns the shape built by the shape construction algorithm
+            generator.Build()
+            # Returns the Face generated by each edge of the first section
+            generated_lower_face = generator.GeneratedFace(bound_root_edge)
+
+            # Write IGES
+            iges_writer = IGESControl_Writer()
+            iges_writer.AddShape(generated_lower_face)
+            iges_writer.Write(lower_face + '.iges')
+
+        if tip:
+            self._check_string(filename=tip)
+            generator = BRepOffsetAPI_ThruSections(False, False, 1e-10)
+            generator.SetMaxDegree(1)
+
+            # npoints_up == npoints_down
+            npoints = len(self.blade_coordinates_down[-1][0])
+            vertices_1 = TColgp_HArray1OfPnt(1, npoints)
+            vertices_2 = TColgp_HArray1OfPnt(1, npoints)
+            for j in range(npoints):
+                vertices_1.SetValue(
+                    j + 1,
+                    gp_Pnt(1000 * self.blade_coordinates_down[-1][0][j],
+                           1000 * self.blade_coordinates_down[-1][1][j],
+                           1000 * self.blade_coordinates_down[-1][2][j]))
+
+                vertices_2.SetValue(
+                    j + 1,
+                    gp_Pnt(1000 * self.blade_coordinates_up[-1][0][j],
+                           1000 * self.blade_coordinates_up[-1][1][j],
+                           1000 * self.blade_coordinates_up[-1][2][j]))
+
+            # Initializes an algorithm for constructing a constrained
+            # BSpline curve passing through the points of the blade last
+            # section, with tolerance = 1e-9
+            bspline_1 = GeomAPI_Interpolate(vertices_1.GetHandle(), False, 1e-9)
+            bspline_1.Perform()
+
+            bspline_2 = GeomAPI_Interpolate(vertices_2.GetHandle(), False, 1e-9)
+            bspline_2.Perform()
+
+            edge_1 = BRepBuilderAPI_MakeEdge(bspline_1.Curve()).Edge()
+            edge_2 = BRepBuilderAPI_MakeEdge(bspline_2.Curve()).Edge()
+
+            # Add BSpline wire to the generator constructor
+            generator.AddWire(BRepBuilderAPI_MakeWire(edge_1).Wire())
+            generator.AddWire(BRepBuilderAPI_MakeWire(edge_2).Wire())
+            # Returns the shape built by the shape construction algorithm
+            generator.Build()
+            # Returns the Face generated by each edge of the first section
+            generated_tip = generator.GeneratedFace(edge_1)
+
+            iges_writer = IGESControl_Writer()
+            iges_writer.AddShape(generated_tip)
+            iges_writer.Write(tip + '.iges')
+
+        if errors:
+            # Write out errors between discrete points and constructed faces
+            self._check_string(filename=errors)
+            self._check_errors(upper_face=upper_face, lower_face=lower_face)
+
+            output_string = '\n'
+            with open(errors + '.txt', 'w') as f:
+                if upper_face:
+                    output_string += '########## UPPER FACE ##########\n\n'
+                    output_string += 'N_section\t\tN_point\t\t\tX_crds\t\t\t\t'
+                    output_string += 'Y_crds\t\t\t\t\tZ_crds\t\t\t\t\tDISTANCE'
+                    output_string += '\n\n'
+                    for i in range(self.n_sections):
+                        alength = len(self.blade_coordinates_up[i][0])
+                        for j in range(alength):
+                            vertex = BRepBuilderAPI_MakeVertex(
+                                gp_Pnt(
+                                    1000 * self.blade_coordinates_up[i][0][j],
+                                    1000 * self.blade_coordinates_up[i][1][j],
+                                    1000 * self.blade_coordinates_up[i][2][
+                                        j])).Vertex()
+                            projection = BRepExtrema_DistShapeShape(
+                                generated_upper_face, vertex)
+                            projection.Perform()
+                            output_string += str(
+                                i) + '\t\t\t' + str(j) + '\t\t\t' + str(
+                                    1000 * self.blade_coordinates_up[i][0]
+                                    [j]) + '\t\t\t'
+                            output_string += str(
+                                1000 * self.blade_coordinates_up[i]
+                                [1][j]) + '\t\t\t' + str(
+                                    1000 * self.blade_coordinates_up[i][2]
+                                    [j]) + '\t\t\t' + str(projection.Value())
+                            output_string += '\n'
+
+                if lower_face:
+                    output_string += '########## LOWER FACE ##########\n\n'
+                    output_string += 'N_section\t\tN_point\t\t\tX_crds\t\t\t\t'
+                    output_string += 'Y_crds\t\t\t\t\tZ_crds\t\t\t\t\tDISTANCE'
+                    output_string += '\n\n'
+                    for i in range(self.n_sections):
+                        alength = len(self.blade_coordinates_down[i][0])
+                        for j in range(alength):
+                            vertex = BRepBuilderAPI_MakeVertex(
+                                gp_Pnt(
+                                    1000 * self.blade_coordinates_down[i][0][j],
+                                    1000 * self.blade_coordinates_down[i][1][j],
+                                    1000 * self.blade_coordinates_down[i][2][
+                                        j])).Vertex()
+                            projection = BRepExtrema_DistShapeShape(
+                                generated_lower_face, vertex)
+                            projection.Perform()
+                            output_string += str(
+                                i) + '\t\t\t' + str(j) + '\t\t\t' + str(
+                                    1000 * self.blade_coordinates_down[i][0]
+                                    [j]) + '\t\t\t'
+                            output_string += str(
+                                1000 * self.blade_coordinates_down[i]
+                                [1][j]) + '\t\t\t' + str(
+                                    1000 * self.blade_coordinates_down[i][2]
+                                    [j]) + '\t\t\t' + str(projection.Value())
+                            output_string += '\n'
+                f.write(output_string)
+
+        if display:
+            display, start_display, add_menu, add_function_to_menu = init_display(
+            )
+
+            ## DISPLAY FACES
+            if upper_face:
+                display.DisplayShape(generated_upper_face, update=True)
+            if lower_face:
+                display.DisplayShape(generated_lower_face, update=True)
+            if tip:
+                display.DisplayShape(generated_tip, update=True)
+            start_display()
+
+    @staticmethod
+    def _check_string(filename):
+        """
+        Private method to check if the parameter type is string
+
+        :param string filename: filename of the generated .iges surface
+        """
+        if not isinstance(filename, str):
+            raise TypeError('IGES filename must be a valid string.')
+
+    @staticmethod
+    def _check_errors(upper_face, lower_face):
+        """
+        Private method to check if either the blade upper face or lower face
+        is passed in the generate_iges method. Otherwise it raises an exception
+
+        :param string upper_face: blade upper face.
+        :param string lower_face: blade lower face.
+        """
+        if not (upper_face or lower_face):
+            raise ValueError('Either upper_face or lower_face must not be None.')
+
     def _abs_to_norm(self, D_prop):
         """
         Private method to normalize the blade parameters.
+
+        :param float D_prop: propeller diameter
         """
         self.radii = self.radii * 2. / D_prop
         self.chord_lengths = self.chord_lengths / D_prop
@@ -357,6 +623,8 @@ def _norm_to_abs(self, D_prop):
         """
         Private method that converts the normalized blade parameters into the
         actual values.
+
+        :param float D_prop: propeller diameter
         """
         self.radii = self.radii * D_prop / 2.
         self.chord_lengths = self.chord_lengths * D_prop

docs/source/_summaries/bladex.blade.Blade._check_errors.rst

@@ -0,0 +1,6 @@
+bladex.blade.Blade._check_errors
+================================
+
+.. currentmodule:: bladex.blade
+
+.. automethod:: Blade._check_errors

docs/source/_summaries/bladex.blade.Blade._check_string.rst

@@ -0,0 +1,6 @@
+bladex.blade.Blade._check_string
+================================
+
+.. currentmodule:: bladex.blade
+
+.. automethod:: Blade._check_string

docs/source/_summaries/bladex.blade.Blade.generate_iges.rst

@@ -0,0 +1,6 @@
+bladex.blade.Blade.generate_iges
+================================
+
+.. currentmodule:: bladex.blade
+
+.. automethod:: Blade.generate_iges

docs/source/blade.rst

@@ -10,15 +10,18 @@ Blade
 	:nosignatures:
 
 	Blade._abs_to_norm
+	Blade._check_errors
 	Blade._check_params
+	Blade._check_string
 	Blade._compute_pitch_angle
 	Blade._induced_rake_from_skew
 	Blade._norm_to_abs
 	Blade._planar_to_cylindrical
 	Blade.apply_transformations
-	Blade.plot
+	Blade.generate_iges
 	Blade.export_ppg
-	
+	Blade.plot
+
 
 .. autoclass:: Blade
 	:members: