Edge styles (silhouettes, contours)

 * Implement Edge styles (silhouettes, contours)
 * Handle face opacity (alpha component) in SVG output
 * Disable joining objects when in batch mode, it crashes blender
 * Prepare support for config settings

Signed-off-by: Antonio Ospite <ospite@studenti.unina.it>

diff --git a/vrm.py b/vrm.py
index 8914045..b3aac25 100755 (executable)
--- a/vrm.py
+++ b/vrm.py
@@ -2,12 +2,12 @@
 """
 Name: 'VRM'
 Blender: 241
 """
 Name: 'VRM'
 Blender: 241

-Group: 'Export'
-Tooltip: 'Vector Rendering Method Export Script'
+Group: 'Render'
+Tooltip: 'Vector Rendering Method script'

 """
 
 __author__ = "Antonio Ospite"
 """
 
 __author__ = "Antonio Ospite"

-__url__ = ["blender"]
+__url__ = ["http://vrm.projects.blender.org"]

 __version__ = "0.3"
 
 __bpydoc__ = """\
 __version__ = "0.3"
 
 __bpydoc__ = """\


@@ -43,19 +43,21 @@ __bpydoc__ = """\
 # 
 # Things TODO for a next release:
 #   - Switch to the Mesh structure, should be considerably faster
 # 
 # Things TODO for a next release:
 #   - Switch to the Mesh structure, should be considerably faster

-#    (partially done, but cannot sort faces, yet)
+#    (partially done, but with Mesh we cannot sort faces, yet)

 #   - Use a better depth sorting algorithm
 #   - Review how selections are made (this script uses selection states of
 #     primitives to represent visibility infos)
 #   - Implement clipping of primitives and do handle object intersections.
 #     (for now only clipping for whole objects is supported).
 #   - Use a better depth sorting algorithm
 #   - Review how selections are made (this script uses selection states of
 #     primitives to represent visibility infos)
 #   - Implement clipping of primitives and do handle object intersections.
 #     (for now only clipping for whole objects is supported).

-#   - Implement Edge Styles (silhouettes, contours, etc.)
+#   - Implement Edge Styles (silhouettes, contours, etc.) (partially done).

 #   - Implement Edge coloring
 #   - Use multiple lighting sources in color calculation
 #   - Implement Edge coloring
 #   - Use multiple lighting sources in color calculation

-#   - Implement Shading Styles?
-#   - Use another representation for the 2D projection? 
+#   - Implement Shading Styles? (for now we use Flat Shading).
+#   - Use a data structure other than Mesh to represent the 2D image? 

 #     Think to a way to merge adjacent polygons that have the same color.
 #     Think to a way to merge adjacent polygons that have the same color.

-#   - Add other Vector Writers.
+#     Or a way to use paths for silhouettes and contours.
+#   - Add Vector Writers other that SVG.
+#   - Consider SMIL for animation handling instead of ECMA Script?

 #
 # ---------------------------------------------------------------------
 #
 #
 # ---------------------------------------------------------------------
 #


@@ -76,17 +78,81 @@ from math import *
 
 # Some global settings
 PRINT_POLYGONS     = True
 
 # Some global settings
 PRINT_POLYGONS     = True

-PRINT_EDGES        = False
-SHOW_HIDDEN_EDGES  = False
+POLYGON_EXPANSION_TRICK = True

 
 

+PRINT_EDGES        = True
+SHOW_HIDDEN_EDGES  = False
+#EDGE_STYLE = 'normal'
+EDGE_STYLE = 'silhouette'

 EDGES_WIDTH = 0.5
 
 EDGES_WIDTH = 0.5
 

-POLYGON_EXPANSION_TRICK = True
-

 RENDER_ANIMATION = False
 
 RENDER_ANIMATION = False
 

-# Does not work in batch mode!!
-#OPTIMIZE_FOR_SPACE = True
+OPTIMIZE_FOR_SPACE = True
+
+OUTPUT_FORMAT = 'SVG'
+
+
+# ---------------------------------------------------------------------
+#
+## Utility Mesh class
+#
+# ---------------------------------------------------------------------
+class MeshUtils:
+    def __init__(self):
+        return
+
+    def getEdgeAdjacentFaces(self, edge, mesh):
+        """Get the faces adjacent to a given edge.
+
+        There can be 0, 1 or more (usually 2) faces adjacent to an edge.
+        """
+        adjface_list = []
+
+        for f in mesh.faces:
+            if (edge.v1 in f.v) and (edge.v2 in f.v):
+                adjface_list.append(f)
+
+        return adjface_list
+
+    def isVisibleEdge(self, e, mesh):
+        """Normal edge selection rule.
+
+        An edge is visible if _any_ of its adjacent faces is selected.
+        Note: if the edge has no adjacent faces we want to show it as well,
+        useful for "edge only" portion of objects.
+        """
+
+        adjacent_faces = self.getEdgeAdjacentFaces(e, mesh)
+
+        if len(adjacent_faces) == 0:
+            return True
+
+        selected_faces = [f for f in adjacent_faces if f.sel]
+
+        if len(selected_faces) != 0:
+            return True
+        else:
+            return False
+
+    def isSilhouetteEdge(self, e, mesh):
+        """Silhuette selection rule.
+
+        An edge is a silhuette edge if it is shared by two faces with
+        different selection status or if it is a boundary edge of a selected
+        face.
+        """
+
+        adjacent_faces = self.getEdgeAdjacentFaces(e, mesh)
+
+        if ((len(adjacent_faces) == 1 and adjacent_faces[0].sel == 1) or
+            (len(adjacent_faces) == 2 and
+                adjacent_faces[0].sel != adjacent_faces[1].sel)
+            ):
+            return True
+        else:
+            return False
+

 
 
 # ---------------------------------------------------------------------
 
 
 # ---------------------------------------------------------------------


@@ -214,9 +280,10 @@ class Projector:
         return m
 
 
         return m
 
 

+

 # ---------------------------------------------------------------------
 #
 # ---------------------------------------------------------------------
 #

-## 2DObject representation class
+## 2D Object representation class

 #
 # ---------------------------------------------------------------------
 
 #
 # ---------------------------------------------------------------------
 


@@ -446,7 +513,7 @@ class SVGVectorWriter(VectorWriter):
 
         for face in mesh.faces:
             if not face.sel:
 
         for face in mesh.faces:
             if not face.sel:

-                continue
+               continue

 
             self.file.write("<polygon points=\"")
 
 
             self.file.write("<polygon points=\"")
 


@@ -475,7 +542,14 @@ class SVGVectorWriter(VectorWriter):
             # Convert the color to the #RRGGBB form
             str_col = "#%02X%02X%02X" % (color[0], color[1], color[2])
 
             # Convert the color to the #RRGGBB form
             str_col = "#%02X%02X%02X" % (color[0], color[1], color[2])
 

+            # Handle transparent polygons
+            opacity_string = ""
+            if color[3] != 255:
+                opacity = float(color[3])/255.0
+                opacity_string = " fill-opacity: %g; stroke-opacity: %g; opacity: 1;" % (opacity, opacity)
+

             self.file.write("\tstyle=\"fill:" + str_col + ";")
             self.file.write("\tstyle=\"fill:" + str_col + ";")

+            self.file.write(opacity_string)

             if POLYGON_EXPANSION_TRICK:
                 self.file.write(" stroke:" + str_col + ";")
                 self.file.write(" stroke-width:" + str(stroke_width) + ";\n")
             if POLYGON_EXPANSION_TRICK:
                 self.file.write(" stroke:" + str_col + ";")
                 self.file.write(" stroke-width:" + str(stroke_width) + ";\n")


@@ -497,8 +571,9 @@ class SVGVectorWriter(VectorWriter):
             
             hidden_stroke_style = ""
             
             
             hidden_stroke_style = ""
             

-            # Consider an edge selected if both vertices are selected
-            if e.v1.sel == 0 or e.v2.sel == 0:
+            # We consider an edge visible if _both_ its vertices are selected,
+            # hence an edge is hidden if _any_ of its vertices is deselected.
+            if e.sel == 0:

                 if showHiddenEdges == False:
                     continue
                 else:
                 if showHiddenEdges == False:
                     continue
                 else:


@@ -635,9 +710,18 @@ class Renderer:
 
         self._doSceneClipping(workScene)
 
 
         self._doSceneClipping(workScene)
 

-        # FIXME: does not work in batch mode!
-        #if OPTIMIZE_FOR_SPACE:
-        #    self._joinMeshObjectsInScene(workScene)
+
+        # XXX: Joining objects does not work in batch mode!!
+        # Do not touch the following if, please :)
+
+        global OPTIMIZE_FOR_SPACE
+        if Blender.mode == 'background':
+            print "\nWARNING! Joining objects not supported in background mode!\n"
+            OPTIMIZE_FOR_SPACE = False
+
+        if OPTIMIZE_FOR_SPACE:
+            self._joinMeshObjectsInScene(workScene)
+

 
         self._doSceneDepthSorting(workScene)
         
 
         self._doSceneDepthSorting(workScene)
         


@@ -652,19 +736,22 @@ class Renderer:
 
             print "Rendering: ", obj.getName()
 
 
             print "Rendering: ", obj.getName()
 

-            mesh = obj.data
+            mesh = obj.getData()

 
             self._doModelToWorldCoordinates(mesh, obj.matrix)
 
             self._doObjectDepthSorting(mesh)
             
 
             self._doModelToWorldCoordinates(mesh, obj.matrix)
 
             self._doObjectDepthSorting(mesh)
             

+            # We use both Mesh and NMesh because for depth sorting we change
+            # face order and Mesh class don't let us to do that.
+            mesh.update()
+            mesh = obj.getData(mesh=1)
+            

             self._doBackFaceCulling(mesh)
             
             self._doColorAndLighting(mesh)
 
             self._doBackFaceCulling(mesh)
             
             self._doColorAndLighting(mesh)
 

-            # TODO: 'style' can be a function that determine
-            # if an edge should be showed?
-            self._doEdgesStyle(mesh, style=None)
+            self._doEdgesStyle(mesh, edgeSelectionStyles[EDGE_STYLE])

 
             self._doProjection(mesh, proj)
             
 
             self._doProjection(mesh, proj)
             


@@ -916,14 +1003,14 @@ class Renderer:
         # Is this the correct way to propagate the face selection info to the
         # vertices belonging to a face ??
         # TODO: Using the Mesh module this should come for free. Right?
         # Is this the correct way to propagate the face selection info to the
         # vertices belonging to a face ??
         # TODO: Using the Mesh module this should come for free. Right?

-        Mesh.Mode(Mesh.SelectModes['VERTEX'])
-        for f in mesh.faces:
-            if not f.sel:
-                for v in f: v.sel = 0;
+        #Mesh.Mode(Mesh.SelectModes['VERTEX'])
+        #for f in mesh.faces:
+        #    if not f.sel:
+        #        for v in f: v.sel = 0;

 
 

-        for f in mesh.faces:
-            if f.sel:
-                for v in f: v.sel = 1;
+        #for f in mesh.faces:
+        #    if f.sel:
+        #        for v in f: v.sel = 1;

 
     def _doColorAndLighting(self, mesh):
         """Apply an Illumination model to the object.
 
     def _doColorAndLighting(self, mesh):
         """Apply an Illumination model to the object.


@@ -935,9 +1022,9 @@ class Renderer:
 
         # If the mesh has vertex colors already, use them,
         # otherwise turn them on and do some calculations
 
         # If the mesh has vertex colors already, use them,
         # otherwise turn them on and do some calculations

-        if mesh.hasVertexColours():
+        if mesh.vertexColors:

             return
             return

-        mesh.hasVertexColours(True)
+        mesh.vertexColors = 1

 
         materials = mesh.materials
         
 
         materials = mesh.materials
         


@@ -997,18 +1084,23 @@ class Renderer:
 
             I = ki + Iamb + Idiff + Ispec
 
 
             I = ki + Iamb + Idiff + Ispec
 

+            # Set Alpha component
+            I = list(I)
+            I.append(mat.getAlpha())
+

             # Clamp I values between 0 and 1
             I = [ min(c, 1) for c in I]
             I = [ max(0, c) for c in I]
             tmp_col = [ int(c * 255.0) for c in I]
 
             # Clamp I values between 0 and 1
             I = [ min(c, 1) for c in I]
             I = [ max(0, c) for c in I]
             tmp_col = [ int(c * 255.0) for c in I]
 

-            vcol = NMesh.Col(tmp_col[0], tmp_col[1], tmp_col[2], 255)
-            f.col = []
-            for v in f.v:
-                f.col.append(vcol)
+            for c in f.col:
+                c.r = tmp_col[0]
+                c.g = tmp_col[1]
+                c.b = tmp_col[2]
+                c.a = tmp_col[3]

 
 

-    def _doEdgesStyle(self, mesh, style):
-        """Process Mesh Edges.
+    def _doEdgesStyle(self, mesh, edgestyleSelect):
+        """Process Mesh Edges accroding to a given selection style.

 
         Examples of algorithms:
 
 
         Examples of algorithms:
 


@@ -1020,9 +1112,16 @@ class Renderer:
             given an edge if one its adjacent faces is frontfacing and the
             other is backfacing, than select it, else deselect.
         """
             given an edge if one its adjacent faces is frontfacing and the
             other is backfacing, than select it, else deselect.
         """

-        #print "\tTODO: _doEdgeStyle()"
-        return

 
 

+        Mesh.Mode(Mesh.SelectModes['EDGE'])
+
+        for e in mesh.edges:
+
+            if edgestyleSelect(e, mesh):
+                e.sel = 1
+            else:
+                e.sel = 0
+                

     def _doProjection(self, mesh, projector):
         """Calculate the Projection for the object.
         """
     def _doProjection(self, mesh, projector):
         """Calculate the Projection for the object.
         """


@@ -1042,6 +1141,20 @@ class Renderer:
 #
 # ---------------------------------------------------------------------
 
 #
 # ---------------------------------------------------------------------
 

+# A dictionary to collect all the different edge styles and their edge
+# selection criteria
+edgeSelectionStyles = {
+        'normal': MeshUtils().isVisibleEdge,
+        'silhouette': MeshUtils().isSilhouetteEdge
+        }
+
+# A dictionary to collect the supported output formats
+outputWriters = {
+        'SVG': SVGVectorWriter,
+        }
+
+
+# A wrapper function for the vectorizing process

 def vectorize(filename):
     """The vectorizing process is as follows:
      
 def vectorize(filename):
     """The vectorizing process is as follows:
      


@@ -1052,21 +1165,13 @@ def vectorize(filename):
     editmode = Window.EditMode()
     if editmode: Window.EditMode(0)
 
     editmode = Window.EditMode()
     if editmode: Window.EditMode(0)
 

-    writer = SVGVectorWriter(filename)
+    writer = outputWriters[OUTPUT_FORMAT](filename)

     
     renderer = Renderer()
     renderer.doRendering(writer, RENDER_ANIMATION)
 
     if editmode: Window.EditMode(1) 
 
     
     renderer = Renderer()
     renderer.doRendering(writer, RENDER_ANIMATION)
 
     if editmode: Window.EditMode(1) 
 

-def vectorize_gui(filename):
-    """Draw the gui.
-
-    I would like to keep that simple, really.
-    """
-    Blender.Window.FileSelector (vectorize, 'Save SVG', filename)
-    Blender.Redraw()
-

 
 # Here the main
 if __name__ == "__main__":
 
 # Here the main
 if __name__ == "__main__":


@@ -1074,8 +1179,9 @@ if __name__ == "__main__":
     basename = Blender.sys.basename(Blender.Get('filename'))
     outputfile = Blender.sys.splitext(basename)[0]+".svg"
 
     basename = Blender.sys.basename(Blender.Get('filename'))
     outputfile = Blender.sys.splitext(basename)[0]+".svg"
 

-    # with this trick we can run the script in batch mode
-    try:
-        vectorize_gui(outputfile)
-    except:
+    if Blender.mode == 'background':

         vectorize(outputfile)
         vectorize(outputfile)

+    else:
+        label = "Save %s" % OUTPUT_FORMAT
+        Blender.Window.FileSelector(vectorize, label, outputfile)
+        Blender.Redraw()