glTF export: enhancement & fixes:

* implement KHR_materials_unlit export
* Fix primitive restart values
* Fix jpg uri/mime type
* Fix bug when image has no color channels
* Check animation has actions
* Ignore meshes without primitives
* Fix materials when not selected in export settings
* Improve error message for invalid animation target type
* Animation with errors are ignored, but export continues
* Export of BaseColorFactor

1 files changed, 17 insertions, 6 deletions

diff --git a/io_scene_gltf2/blender/exp/gltf2_blender_gather_image.py b/io_scene_gltf2/blender/exp/gltf2_blender_gather_image.py
index a694cac3..6b969668 100755
--- a/io_scene_gltf2/blender/exp/gltf2_blender_gather_image.py
+++ b/io_scene_gltf2/blender/exp/gltf2_blender_gather_image.py
@@ -11,6 +11,7 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+import re
 
 import bpy
 import typing
@@ -30,13 +31,17 @@ def gather_image(
         export_settings):
     if not __filter_image(blender_shader_sockets_or_texture_slots, export_settings):
         return None
+
+    uri = __gather_uri(blender_shader_sockets_or_texture_slots, export_settings)
+    mime_type = __gather_mime_type(uri.filepath if uri is not None else "")
+
     image = gltf2_io.Image(
         buffer_view=__gather_buffer_view(blender_shader_sockets_or_texture_slots, export_settings),
         extensions=__gather_extensions(blender_shader_sockets_or_texture_slots, export_settings),
         extras=__gather_extras(blender_shader_sockets_or_texture_slots, export_settings),
-        mime_type=__gather_mime_type(blender_shader_sockets_or_texture_slots, export_settings),
+        mime_type=mime_type,
         name=__gather_name(blender_shader_sockets_or_texture_slots, export_settings),
-        uri=__gather_uri(blender_shader_sockets_or_texture_slots, export_settings)
+        uri=uri
     )
     return image
 
@@ -51,7 +56,7 @@ def __gather_buffer_view(sockets_or_slots, export_settings):
     if export_settings[gltf2_blender_export_keys.FORMAT] != 'GLTF_SEPARATE':
         image = __get_image_data(sockets_or_slots, export_settings)
         return gltf2_io_binary_data.BinaryData(
-            data=image.to_image_data(__gather_mime_type(sockets_or_slots, export_settings)))
+            data=image.to_image_data(__gather_mime_type()))
     return None
 
 
@@ -63,9 +68,13 @@ def __gather_extras(sockets_or_slots, export_settings):
     return None
 
 
-def __gather_mime_type(sockets_or_slots, export_settings):
-    return 'image/png'
-    # return 'image/jpeg'
+def __gather_mime_type(filepath=""):
+    extension_types = {'.png': 'image/png', '.jpg': 'image/jpeg', '.jpeg': 'image/jpeg'}
+    default_extension = extension_types['.png']
+
+    matches = re.findall(r'\.\w+$', filepath)
+    extension = matches[0] if len(matches) > 0 else default_extension
+    return extension_types[extension] if extension.lower() in extension_types.keys() else default_extension
 
 
 def __gather_name(sockets_or_slots, export_settings):
@@ -98,6 +107,8 @@ def __get_image_data(sockets_or_slots, export_settings):
     # in a helper class. During generation of the glTF in the exporter these will then be combined to actual binary
     # ressources.
     def split_pixels_by_channels(image: bpy.types.Image, export_settings) -> typing.List[typing.List[float]]:
+        assert image.channels > 0, "Image '{}' has no color channels and cannot be exported.".format(image.name)
+
         channelcache = export_settings['gltf_channelcache']
         if image.name in channelcache:
             return channelcache[image.name]