Blender addons for exporting material

blender_mtl_exporter.py

'''
# blender-mtl-exporter
This addons can export all custom properties of all materials in the *.blend file

# Usage
Just open the "File > Export > Material (.mtl)"

'''

import bpy
from bpy_extras.io_utils import ExportHelper

bl_info = {
  "name": "My Material Exporter",
  "category": "Import-Export",
  "location": "File > Export",
  "author": "Ghorte",
  "description": "Export all materials in this .blend file."
}

class ExportMtl(bpy.types.Operator, ExportHelper):
  bl_idname = "export.mtl"
  bl_label = "Export Material"

  filename_ext = ".mtl"

  def invoke(self, context, event):
    return ExportHelper.invoke(self, context, event)

  @classmethod
  def poll(cls, context):
    return context.active_object is not None

  def execute(self, context):
    if not self.properties.filepath:
      raise Exception("filename not set")

    write_out = \
"""\
# Blender Material Custom Properties '%s'
# Material Count: %d

""" % (bpy.data.filepath, len(bpy.data.materials))

    for mat in bpy.data.materials:
      write_out = write_out + "newmtl %s\n" % mat.name

      for k in mat.keys():
        if (k.startswith("_")):
          continue
        write_out = write_out + "%s %s\n" % (k, str(mat.get(k)))

      write_out = write_out + "\n"

    with open(self.filepath, mode="w") as stream:
      stream.write(write_out)

    return {"FINISHED"}

def menu_func_export(self, context):
  default_path = bpy.data.filepath.replace(".blend", ".mtl")
  text = "Material (.mtl)"
  operator = self.layout.operator(ExportMtl.bl_idname, text=text)
  operator.filepath = default_path

def register():
  bpy.utils.register_module(__name__)
  bpy.types.INFO_MT_file_export.append(menu_func_export)

def unregister():
  bpy.utils.unregister_module(__name__)
  bpy.types.INFO_MT_file_export.remove(menu_func_export)

if __name__ == "__main__":
  register()