glTF exporter: fix export when texture is used only for alpha

1 files changed, 9 insertions, 5 deletions

diff --git a/io_scene_gltf2/blender/exp/gltf2_blender_gather_materials_pbr_metallic_roughness.py b/io_scene_gltf2/blender/exp/gltf2_blender_gather_materials_pbr_metallic_roughness.py
index a6a28fc4..5b3c1bc6 100755
--- a/io_scene_gltf2/blender/exp/gltf2_blender_gather_materials_pbr_metallic_roughness.py
+++ b/io_scene_gltf2/blender/exp/gltf2_blender_gather_materials_pbr_metallic_roughness.py
@@ -81,12 +81,16 @@ def __gather_base_color_texture(blender_material, export_settings):
         base_color_socket = gltf2_blender_get.get_socket_old(blender_material, "BaseColor")
 
     alpha_socket = gltf2_blender_get.get_socket(blender_material, "Alpha")
-    if alpha_socket is not None and alpha_socket.is_linked:
-        inputs = (base_color_socket, alpha_socket, )
-    else:
-        inputs = (base_color_socket,)
 
-    return gltf2_blender_gather_texture_info.gather_texture_info(base_color_socket, inputs, export_settings)
+    # keep sockets that have some texture : color and/or alpha
+    inputs = tuple(
+        socket for socket in [base_color_socket, alpha_socket]
+        if socket is not None and __has_image_node_from_socket(socket)
+    )
+    if not inputs:
+        return None
+
+    return gltf2_blender_gather_texture_info.gather_texture_info(inputs[0], inputs, export_settings)
 
 
 def __gather_extensions(blender_material, export_settings):