From BlenderWiki
An example of a simple addon which adds an add spindle option to the add mesh menu. (Wow, lots of ads in that one, pardon the pun.)
bl_info = { "name": "Spindle", "author": "Your_name_here, Your_co_developers_name_here", "version": (0,1), "blender": (2, 5, 5), "api": 35853, "location": "View3D > Add > Mesh", "description": "Adds Spindle Object.", "warning": "", "wiki_url": "http://wiki.blender.org/index.php/Extensions:2.5/Py/"\ "Scripts/Add_Mesh/", "tracker_url": "", "category": "Add Mesh"} import bpy from mathutils import * from math import * from bpy.props import * def align_matrix(context): loc = Matrix.Translation(context.scene.cursor_location) obj_align = context.user_preferences.edit.object_align if (context.space_data.type == 'VIEW_3D' and obj_align == 'VIEW'): rot = context.space_data.region_3d.view_matrix.rotation_part().invert().resize4x4() else: rot = Matrix() align_matrix = loc * rot return align_matrix def create_mesh_object(context, verts, edges, faces, name, edit, align_matrix): scene = context.scene obj_act = scene.objects.active # Can't edit anything, unless we have an active obj. if edit and not obj_act: return None # Create new mesh mesh = bpy.data.meshes.new(name) # Make a mesh from a list of verts/edges/faces. mesh.from_pydata(verts, edges, faces) # Update mesh geometry after adding stuff. mesh.update() # Deselect all objects. bpy.ops.object.select_all(action='DESELECT') if edit: # Replace geometry of existing object # Use the active obj and select it. ob_new = obj_act ob_new.select = True if obj_act.mode == 'OBJECT': # Get existing mesh datablock. old_mesh = ob_new.data # Set object data to nothing ob_new.data = None # Clear users of existing mesh datablock. old_mesh.user_clear() # Remove old mesh datablock if no users are left. if (old_mesh.users == 0): bpy.data.meshes.remove(old_mesh) # Assign new mesh datablock. ob_new.data = mesh else: # Create new object ob_new = bpy.data.objects.new(name, mesh) # Link new object to the given scene and select it. scene.objects.link(ob_new) ob_new.select = True # Place the object at the 3D cursor location. # apply viewRotaion ob_new.matrix_world = align_matrix if obj_act and obj_act.mode == 'EDIT': if not edit: # We are in EditMode, switch to ObjectMode. bpy.ops.object.mode_set(mode='OBJECT') # Select the active object as well. obj_act.select = True # Apply location of new object. scene.update() # Join new object into the active. bpy.ops.object.join() # Switching back to EditMode. bpy.ops.object.mode_set(mode='EDIT') ob_new = obj_act else: # We are in ObjectMode. # Make the new object the active one. scene.objects.active = ob_new return ob_new def createFaces(vertIdx1, vertIdx2, closed=False, flipped=False): faces = [] if not vertIdx1 or not vertIdx2: return None if len(vertIdx1) < 2 and len(vertIdx2) < 2: return None fan = False if (len(vertIdx1) != len(vertIdx2)): if (len(vertIdx1) == 1 and len(vertIdx2) > 1): fan = True else: return None total = len(vertIdx2) if closed: # Bridge the start with the end. if flipped: face = [ vertIdx1[0], vertIdx2[0], vertIdx2[total - 1]] if not fan: face.append(vertIdx1[total - 1]) faces.append(face) else: face = [vertIdx2[0], vertIdx1[0]] if not fan: face.append(vertIdx1[total - 1]) face.append(vertIdx2[total - 1]) faces.append(face) # Bridge the rest of the faces. for num in range(total - 1): if flipped: if fan: face = [vertIdx2[num], vertIdx1[0], vertIdx2[num + 1]] else: face = [vertIdx2[num], vertIdx1[num], vertIdx1[num + 1], vertIdx2[num + 1]] faces.append(face) else: if fan: face = [vertIdx1[0], vertIdx2[num], vertIdx2[num + 1]] else: face = [vertIdx1[num], vertIdx2[num], vertIdx2[num + 1], vertIdx1[num + 1]] faces.append(face) return faces def add_spindle(segments, radius, height, cap_height): verts = [] faces = [] tot_verts = segments * 2 + 2 half_height = height / 2.0 # Upper tip idx_upper_tip = len(verts) verts.append(Vector((0, 0, half_height + cap_height))) # Lower tip idx_lower_tip = len(verts) verts.append(Vector((0.0, 0.0, -half_height - cap_height))) upper_edgeloop = [] lower_edgeloop = [] for index in range(segments): mtx = Matrix.Rotation(2.0 * pi * float(index) / segments, 3, 'Z') # Calculate index & location of upper verte4x tip. idx_up = len(verts) upper_edgeloop.append(idx_up) verts.append(Vector((radius, 0.0, half_height)) * mtx) if height > 0: idx_low = len(verts) lower_edgeloop.append(idx_low) verts.append(Vector((radius, 0.0, -half_height)) * mtx) # Create faces for the upper tip. tip_up_faces = createFaces([idx_upper_tip], upper_edgeloop, closed=True, flipped=True) faces.extend(tip_up_faces) if height > 0: # Create faces for the middle cylinder. cyl_faces = createFaces(lower_edgeloop, upper_edgeloop, closed=True) faces.extend(cyl_faces) # Create faces for the lower tip. tip_low_faces = createFaces([idx_lower_tip], lower_edgeloop, closed=True) faces.extend(tip_low_faces) else: # Skipping middle part/cylinder (height=0). # Create faces for the lower tip. tip_low_faces = createFaces([idx_lower_tip], upper_edgeloop, closed=True) faces.extend(tip_low_faces) return verts, faces class AddSpindle(bpy.types.Operator): '''Add a spindle mesh.''' bl_idname = "mesh.primitive_spindle_add" bl_label = "Add Spindle" bl_description = "Create a spindle mesh." bl_options = {'REGISTER', 'UNDO'} # edit - Whether to add or update. edit = BoolProperty(name="", description="", default=False, options={'HIDDEN'}) segments = IntProperty(name="Segments", description="Number of segments of the spindle", min=3, max=512, default=32) radius = FloatProperty(name="Radius", description="Radius of the spindle", min=0.01, max=9999.0, default=1.0) height = FloatProperty(name="Height", description="Height of the spindle", min=0.0, max=100.0, default=1.0) cap_height = FloatProperty(name="Cap Height", description="Cap height of the spindle", min=-9999.0, max=9999.0, default=0.5) align_matrix = Matrix() def execute(self, context): verts, faces = add_spindle( self.segments, self.radius, self.height, self.cap_height) obj = create_mesh_object(context, verts, [], faces, "Spindle", self.edit, self.align_matrix) return {'FINISHED'} def invoke(self, context, event): self.align_matrix = align_matrix(context) self.execute(context) return {'FINISHED'} def menu_func(self, context): self.layout.operator(AddSpindle.bl_idname, text="Spindle", icon='PLUGIN') def register(): bpy.utils.register_module(__name__) bpy.types.INFO_MT_mesh_add.append(menu_func) def unregister(): bpy.utils.unregister_module(__name__) bpy.types.INFO_MT_mesh_add.remove(menu_func) if __name__ == "__main__": register()