Fix tutorial for blender_sdf_exporter (#1718)

* Fix tutorial for blender_sdf_exporter Signed-off-by: Andrej Orsula <orsula.andrej@gmail.com> * Remove unused import Signed-off-by: Andrej Orsula <orsula.andrej@gmail.com> * Use path submodule where possible Signed-off-by: Andrej Orsula <orsula.andrej@gmail.com> * Use f strings Signed-off-by: Andrej Orsula <orsula.andrej@gmail.com> * Format Python with black Signed-off-by: Andrej Orsula <orsula.andrej@gmail.com> Signed-off-by: Andrej Orsula <orsula.andrej@gmail.com>
gazebosim · Oct 10, 2022 · 6f912e3 · 6f912e3
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diff --git a/examples/scripts/blender/sdf_exporter.py b/examples/scripts/blender/sdf_exporter.py
@@ -1,67 +1,82 @@
-import bpy
-import os.path
-from bpy_extras.io_utils import ImportHelper
-from bpy.props import StringProperty, BoolProperty
-from bpy.types import Operator
-
 import xml.etree.ElementTree as ET
+from os import path
 from xml.dom import minidom
 
-# Target blender version: 2.82
+import bpy
+from bpy.props import StringProperty
+from bpy.types import Operator
+from bpy_extras.io_utils import ImportHelper
+
+# Tested Blender version: 2.82/3.2
 
 ########################################################################################################################
 ### Exports model.dae of the scene with textures, its corresponding model.sdf file, and a default model.config file ####
 ########################################################################################################################
 def export_sdf(prefix_path):
 
-    dae_filename = 'model.dae'
-    sdf_filename = 'model.sdf'
-    model_config_filename = 'model.config'
-    lightmap_filename = 'LightmapBaked.png'
-    model_name = 'my_model'
-    meshes_folder_prefix = 'meshes/'
-    
+    dae_filename = "model.dae"
+    sdf_filename = "model.sdf"
+    model_config_filename = "model.config"
+    lightmap_filename = "LightmapBaked.png"
+    model_name = "my_model"
+    meshes_folder_prefix = "meshes/"
+
     # Exports the dae file and its associated textures
-    bpy.ops.wm.collada_export(filepath=prefix_path+meshes_folder_prefix+dae_filename, check_existing=False, filter_blender=False, filter_image=False, filter_movie=False, filter_python=False, filter_font=False, filter_sound=False, filter_text=False, filter_btx=False, filter_collada=True, filter_folder=True, filemode=8)
+    bpy.ops.wm.collada_export(
+        filepath=path.join(prefix_path, meshes_folder_prefix, dae_filename),
+        check_existing=False,
+        filter_blender=False,
+        filter_image=False,
+        filter_movie=False,
+        filter_python=False,
+        filter_font=False,
+        filter_sound=False,
+        filter_text=False,
+        filter_btx=False,
+        filter_collada=True,
+        filter_folder=True,
+        filemode=8,
+    )
 
     # objects = bpy.context.selected_objects
     objects = bpy.context.selectable_objects
-    mesh_objects = [ o for o in objects if o.type == 'MESH' ]
-    light_objects = [ o for o in objects if o.type == 'LIGHT' ]
+    mesh_objects = [o for o in objects if o.type == "MESH"]
+    light_objects = [o for o in objects if o.type == "LIGHT"]
 
     #############################################
     #### export sdf xml based off the scene #####
     #############################################
-    sdf = ET.Element('sdf', attrib={'version':'1.8'})
+    sdf = ET.Element("sdf", attrib={"version": "1.8"})
 
     # 1 model and 1 link
-    model = ET.SubElement(sdf, "model", attrib={"name":"test"})
+    model = ET.SubElement(sdf, "model", attrib={"name": "test"})
     static = ET.SubElement(sdf, "static")
     static.text = "true"
-    link = ET.SubElement(model, "link", attrib={"name":"testlink"})
+    link = ET.SubElement(model, "link", attrib={"name": "testlink"})
     # for each geometry in geometry library add a <visual> tag
     for o in mesh_objects:
-        visual = ET.SubElement(link, "visual", attrib={"name":o.name})
+        visual = ET.SubElement(link, "visual", attrib={"name": o.name})
 
         geometry = ET.SubElement(visual, "geometry")
         mesh = ET.SubElement(geometry, "mesh")
         uri = ET.SubElement(mesh, "uri")
-        uri.text = dae_filename
+        uri.text = path.join(meshes_folder_prefix, dae_filename)
         submesh = ET.SubElement(mesh, "submesh")
         submesh_name = ET.SubElement(submesh, "name")
         submesh_name.text = o.name
-        
+
         # grab diffuse/albedo map
-        diffuse_map = ""    
-        nodes = o.active_material.node_tree.nodes
-        principled = next(n for n in nodes if n.type == 'BSDF_PRINCIPLED')
-        if principled is not None:
-            base_color = principled.inputs['Base Color'] #Or principled.inputs[0]
-            value = base_color.default_value
-            if len(base_color.links):
-                link_node = base_color.links[0].from_node
-                diffuse_map = link_node.image.name
-
+        diffuse_map = ""
+        if o.active_material is not None:
+            nodes = o.active_material.node_tree.nodes
+            principled = next(n for n in nodes if n.type == "BSDF_PRINCIPLED")
+            if principled is not None:
+                base_color = principled.inputs["Base Color"]  # Or principled.inputs[0]
+                value = base_color.default_value
+                if len(base_color.links):
+                    link_node = base_color.links[0].from_node
+                    diffuse_map = link_node.image.name
+
         # setup diffuse/specular color
         material = ET.SubElement(visual, "material")
         diffuse = ET.SubElement(material, "diffuse")
@@ -72,16 +87,16 @@ def export_sdf(prefix_path):
         metal = ET.SubElement(pbr, "metal")
         if diffuse_map != "":
             albedo_map = ET.SubElement(metal, "albedo_map")
-            albedo_map.text = meshes_folder_prefix + diffuse_map
-        
+            albedo_map.text = path.join(meshes_folder_prefix, diffuse_map)
+
         # for lightmapping, add the UV and turn off casting of shadows
-        if os.path.isfile(lightmap_filename):
-            light_map = ET.SubElement(metal, "light_map", attrib={"uv_set":"1"})
-            light_map.text = meshes_folder_prefix + lightmap_filename
-            
+        if path.isfile(lightmap_filename):
+            light_map = ET.SubElement(metal, "light_map", attrib={"uv_set": "1"})
+            light_map.text = path.join(meshes_folder_prefix, lightmap_filename)
+
             cast_shadows = ET.SubElement(visual, "cast_shadows")
             cast_shadows.text = "0"
-        
+
     def add_attenuation_tags(light_tag, blender_light):
         attenuation = ET.SubElement(light, "attenuation")
         range = ET.SubElement(attenuation, "range")
@@ -92,116 +107,128 @@ def add_attenuation_tags(light_tag, blender_light):
         quad_attenuation.text = str(blender_pointlight.quadratic_coefficient)
         const_attenuation = ET.SubElement(attenuation, "constant")
         const_attenuation.text = str(blender_pointlight.constant_coefficient)
-    
+
     # export lights
     for l in light_objects:
         blender_light = l.data
-        
+
         if blender_light.type == "POINT":
-            light = ET.SubElement(link, "light", attrib={"name":l.name, "type":"point"})
+            light = ET.SubElement(
+                link, "light", attrib={"name": l.name, "type": "point"}
+            )
             diffuse = ET.SubElement(light, "diffuse")
-            diffuse.text = str(blender_light.color.r) + " " + str(blender_light.color.g) + " " + str(blender_light.color.b) + " 1.0"
+            diffuse.text = f"{blender_light.color.r} {blender_light.color.g} {blender_light.color.b} 1.0"
             blender_pointlight = bpy.types.PointLight(blender_light)
-            
+
             add_attenuation_tags(light, blender_pointlight)
-            
+
         if blender_light.type == "SPOT":
-            light = ET.SubElement(link, "light", attrib={"name":l.name, "type":"spot"})
+            light = ET.SubElement(
+                link, "light", attrib={"name": l.name, "type": "spot"}
+            )
             diffuse = ET.SubElement(light, "diffuse")
-            diffuse.text = str(blender_light.color.r) + " " + str(blender_light.color.g) + " " + str(blender_light.color.b) + " 1.0"
+            diffuse.text = f"{blender_light.color.r} {blender_light.color.g} {blender_light.color.b} 1.0"
             blender_spotlight = bpy.types.SpotLight(blender_light)
-            
+
             add_attenuation_tags(light, blender_spotlight)
             # note: unsupported <spot> tags in blender
-            
+
         if blender_light.type == "SUN":
-            light = ET.SubElement(link, "light", attrib={"name":l.name, "type":"directional"})
+            light = ET.SubElement(
+                link, "light", attrib={"name": l.name, "type": "directional"}
+            )
             diffuse = ET.SubElement(light, "diffuse")
-            diffuse.text = str(blender_light.color.r) + " " + str(blender_light.color.g) + " " + str(blender_light.color.b) + " 1.0"
+            diffuse.text = f"{blender_light.color.r} {blender_light.color.g} {blender_light.color.b} 1.0"
             blender_pointlight = bpy.types.SunLight(blender_light)
-            
+
         if blender_light.type == "SUN" or blender_light.type == "SPOT":
             direction = ET.SubElement(light, "direction")
-            direction.text = str(l.matrix_world[0][2]) + " " + str(l.matrix_world[1][2]) + " " + str(l.matrix_world[2][2])
-
+            direction.text = (
+                f"{l.matrix_world[0][2]} {l.matrix_world[1][2]} {l.matrix_world[2][2]}"
+            )
+
         # unsupported: AREA lights
 
         cast_shadows = ET.SubElement(light, "cast_shadows")
         cast_shadows.text = "true"
-        
+
         # todo : bpy.types.light script api lacks an intensity value, possible candidate is energy/power(Watts)?
         intensity = ET.SubElement(light, "intensity")
         intensity.text = "1.0"
-    
+
     ## sdf collision tags
-    collision = ET.SubElement(link, "collision", attrib={"name":"collision"})
+    collision = ET.SubElement(link, "collision", attrib={"name": "collision"})
 
     geometry = ET.SubElement(collision, "geometry")
     mesh = ET.SubElement(geometry, "mesh")
     uri = ET.SubElement(mesh, "uri")
-    uri.text = dae_filename
+    uri.text = path.join(meshes_folder_prefix, dae_filename)
 
     surface = ET.SubElement(collision, "surface")
     contact = ET.SubElement(collision, "contact")
     collide_bitmask = ET.SubElement(collision, "collide_bitmask")
     collide_bitmask.text = "0x01"
 
     ## sdf write to file
-    xml_string = ET.tostring(sdf, encoding='unicode')
+    xml_string = ET.tostring(sdf, encoding="unicode")
     reparsed = minidom.parseString(xml_string)
 
-    sdf_file = open(prefix_path+sdf_filename, "w")
+    sdf_file = open(path.join(prefix_path, sdf_filename), "w")
     sdf_file.write(reparsed.toprettyxml(indent="  "))
     sdf_file.close()
 
     ##############################
     ### generate model.config ####
     ##############################
-    model = ET.Element('model')
-    name = ET.SubElement(model, 'name')
+    model = ET.Element("model")
+    name = ET.SubElement(model, "name")
     name.text = model_name
-    version = ET.SubElement(model, 'version')
+    version = ET.SubElement(model, "version")
     version.text = "1.0"
-    sdf_tag = ET.SubElement(model, "sdf", attrib={"sdf":"1.8"})
+    sdf_tag = ET.SubElement(model, "sdf", attrib={"sdf": "1.8"})
     sdf_tag.text = sdf_filename
 
-    author = ET.SubElement(model, 'author')
-    name = ET.SubElement(author, 'name')
+    author = ET.SubElement(model, "author")
+    name = ET.SubElement(author, "name")
     name.text = "Generated by blender SDF tools"
 
-    xml_string = ET.tostring(model, encoding='unicode')
+    xml_string = ET.tostring(model, encoding="unicode")
     reparsed = minidom.parseString(xml_string)
 
-    config_file = open(prefix_path+model_config_filename, "w")
+    config_file = open(path.join(prefix_path, model_config_filename), "w")
     config_file.write(reparsed.toprettyxml(indent="  "))
     config_file.close()
 
 
 #### UI Handling ####
 class OT_TestOpenFilebrowser(Operator, ImportHelper):
-  bl_idname = "test.open_filebrowser"
-  bl_label = "Save"
-
-  directory : bpy.props.StringProperty(name="Outdir Path")
-
-  def execute(self, context):
-    """Do the export with the selected file."""
-
-    if not os.path.isdir(self.directory):
-        print(self.directory + " is not a directory!")
-    else:
-        print("exporting to directory: " + self.directory)
-        export_sdf(self.directory)
-    return {'FINISHED'}
-
-def register(): 
-    bpy.utils.register_class(OT_TestOpenFilebrowser) 
-def unregister(): 
+    bl_idname = "test.open_filebrowser"
+    bl_label = "Save"
+
+    directory: StringProperty(name="Outdir Path")
+
+    def execute(self, context):
+        """Do the export with the selected file."""
+
+        if not path.isdir(self.directory):
+            print(f"{self.directory} is not a directory!")
+        else:
+            print(f"exporting to directory: {self.directory}")
+            export_sdf(self.directory)
+        return {"FINISHED"}
+
+
+def register():
+    bpy.utils.register_class(OT_TestOpenFilebrowser)
+
+
+def unregister():
     bpy.utils.unregister_class(OT_TestOpenFilebrowser)
-
+
+
 if __name__ == "__main__":
-    register() 
-    bpy.ops.test.open_filebrowser('INVOKE_DEFAULT')
+    register()
+    bpy.ops.test.open_filebrowser("INVOKE_DEFAULT")
 
 # alternatively comment the main code block and do a function call without going through all the ui
 # prefix_path = '/home/ddeng/blender_lightmap/final_office/office/'

diff --git a/tutorials/blender_sdf_exporter.md b/tutorials/blender_sdf_exporter.md
@@ -4,18 +4,18 @@ Blender is a Digital Content Creation (DCC) tool for working with 3d models.
 In some cases you may be using it to bake lighting and environment maps.
 
 The Blender SDF exporter is a blender script in which you can run within Blender to
-export your meshes, their associated textures and lights to a dae file, its 
+export your meshes, their associated textures and lights to a dae file, its
 corresponding SDF file and config file.
 
 Please note that the SDF format does not have 1 to 1 parity of features with Blender's
 mesh/materials/lights feature set. As such feel free to customize the script as needed.
 
 ## Using the Blender SDF Exporter
 
-1. Download the blender script in [sdf_exporter.py](https://github.com/gazebosim/gz-sim/tree/ign-gazebo5/examples/scripts/blender/sdf_exporter.py). 
+1. Download the blender script in [sdf_exporter.py](https://github.com/gazebosim/gz-sim/tree/gz-sim7/examples/scripts/blender/sdf_exporter.py).
 
 2. Open the script under Blender's Scripting tab and run it.
 
-3. You will see a file dialog requesting for a location to save the files to. Hit 'Save' when you are done.
+3. You will see a file dialog requesting a location to save the files to. Hit 'Save' when you are done.
 
 4. The files `meshes/model.dae`, `model.config` and `model.sdf` will be created at the location you specified.