primitive json exporter

blender_exporter.py

import bpy
import string
import mathutils
from mathutils import *
from math import radians, pi
# https://docs.blender.org/api/blender_python_api_current/bpy.types.MeshVertex.html#bpy.types.MeshVertex
# https://docs.blender.org/api/blender_python_api_current/bpy.types.Mesh.html
# https://docs.blender.org/api/blender_python_api_current/mathutils.html
# https://docs.blender.org/api/blender_python_api_current/bpy.types.Object.html#bpy.types.Object
def write_some_data(context, filepath, use_some_setting):
    print("running write_some_data...")
    f = open(filepath, 'w', encoding='utf-8')
    f.write("[ ")   
    # f.write("Hello World %s" % use_some_setting)
    # if self.Config.SelectedOnly:
    #     ExportList = list(self.context.selected_objects)
    # else:
    ExportList = list(context.scene.objects)
    first = True
    for Object in ExportList:
            if first:
                f.write("{\n")
                first = False
            else:
                f.write(",\n{\n")
            f.write("   \"type_name\": \""+Object.type+"\", \n")
            f.write("   \"name\": \""+Object.name+"\", \n")
            #f.write("   \"matrix\": ["+print_matrix(Object.matrix_local)+"], \n")
            #mat = Object.matrix_world * mathutils.Matrix(Object.matrix_local)
            mat = mathutils.Matrix(Object.matrix_local)
            #mat = mat * Matrix.Rotation(radians(90), 4, 'X')
            if Object.type == 'EMPTY':
                vec = mathutils.Vector((0.0, 0.0, 0.0))
                vec = mat * vec
                #print(vec)
                #print("   \"matrix\": ["+print_matrix(mat)+"], \n")
                f.write("   \"points\": [ ["+("{:9f}, {:9f}, {:9f}".format(vec[0],vec[1],vec[2]))+"] ], \n")
            elif Object.type == 'MESH':
                f.write("   \"points\": [ "+print_polygons_verts(mat, Object.data)+" ], \n")
            f.write("}")               
    f.write(" ]")        
    f.close()
    print("well done")
    return {'FINISHED'}

def print_polygons_verts(mat, mesh_data):
    result = ""
    first = True
    mat90 = Matrix.Rotation(radians(90), 4, 'X')
    for poly in mesh_data.polygons:
        #print("Polygon index: %d, length: %d" % (poly.index, poly.loop_total))

        for polyli in poly.loop_indices:
            coco = mesh_data.vertices[mesh_data.loops[polyli].vertex_index].co
            vec = mat * coco
            #vec = mat90 * vec
            print(vec, coco)
            if first:
                first = False
                result += "[{:9f}, {:9f}, {:9f}]".format(vec[0], vec[1], vec[2])
            else:
                result += ", [{:9f}, {:9f}, {:9f}]".format(vec[0], vec[1], vec[2])
            #print("    Vertex: %d" % mesh_data.loops[polyli].vertex_index)
            #print("    Vertex: ", mesh_data.vertices[mesh_data.loops[polyli].vertex_index].co)
            
            
    #print(result)
    return result
    # range is used here to show how the polygons reference loops,
    # for convenience 'poly.loop_indices' can be used instead.
    #for loop_index in range(poly.loop_start, poly.loop_start + poly.loop_total):
    #    print("    Vertex: %d" % me.loops[loop_index].vertex_index)
     #   print("    UV: %r" % uv_layer[loop_index].uv)

def print_matrix(m):
    result = "{:9f}, {:9f}, {:9f}, {:9f}, {:9f}, {:9f}, {:9f}, {:9f}, {:9f}, {:9f}, {:9f}, {:9f}, {:9f}, {:9f}, {:9f}, {:9f}".format(
     m[0][0], m[0][1],m[0][2],m[0][3],
     m[1][0],m[1][1],m[1][2],m[1][3],
     m[2][0],m[2][1],m[2][2],m[2][3],
     m[3][0],m[3][1],m[3][2],m[3][3])
    return result

# ExportHelper is a helper class, defines filename and
# invoke() function which calls the file selector.
from bpy_extras.io_utils import ExportHelper
from bpy.props import StringProperty, BoolProperty, EnumProperty
from bpy.types import Operator


class ExportSomeData(Operator, ExportHelper):
    """This appears in the tooltip of the operator and in the generated docs"""
    bl_idname = "export_scene.test_dataexport"  # important since its how bpy.ops.import_test.some_data is constructed
    bl_label = "I NEED EXPORT"

    # ExportHelper mixin class uses this
    filename_ext = ".txt"

    filter_glob = StringProperty(
            default="*.txt",
            options={'HIDDEN'},
            )

    # List of operator properties, the attributes will be assigned
    # to the class instance from the operator settings before calling.
    use_setting = BoolProperty(
            name="Example Boolean",
            description="Example Tooltip",
            default=True,
            )

    type = EnumProperty(
            name="Example Enum",
            description="Choose between two items",
            items=(('OPT_A', "First Option", "Description one"),
                   ('OPT_B', "Second Option", "Description two")),
            default='OPT_A',
            )

    def execute(self, context):
        return write_some_data(context, self.filepath, self.use_setting)


# Only needed if you want to add into a dynamic menu
def menu_func_export(self, context):
    self.layout.operator(ExportSomeData.bl_idname, text="Text Export Operator")


def register():
    bpy.utils.register_class(ExportSomeData)
    bpy.types.INFO_MT_file_export.append(menu_func_export)


def unregister():
    bpy.utils.unregister_class(ExportSomeData)
    bpy.types.INFO_MT_file_export.remove(menu_func_export)


if __name__ == "__main__":
    register()
    print("in main...")
    # test call
    bpy.ops.export_scene.test_dataexport('INVOKE_DEFAULT')