glTF export: Fix T78754: export alpha scalar value (not coming from texture)

3 files changed, 9 insertions, 9 deletions

diff --git a/io_scene_gltf2/__init__.py b/io_scene_gltf2/__init__.py
index 2e19cbeb..211839f8 100755
--- a/io_scene_gltf2/__init__.py
+++ b/io_scene_gltf2/__init__.py
@@ -15,7 +15,7 @@
 bl_info = {
     'name': 'glTF 2.0 format',
     'author': 'Julien Duroure, Norbert Nopper, Urs Hanselmann, Moritz Becher, Benjamin Schmithüsen, Jim Eckerlein, and many external contributors',
-    "version": (1, 3, 29),
+    "version": (1, 3, 30),
     'blender': (2, 90, 0),
     'location': 'File > Import-Export',
     'description': 'Import-Export as glTF 2.0',
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 54493799..7913d175 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
@@ -47,6 +47,9 @@ def __filter_pbr_material(blender_material, export_settings):
 
 
 def __gather_base_color_factor(blender_material, export_settings):
+    alpha_socket = gltf2_blender_get.get_socket(blender_material, "Alpha")
+    alpha = alpha_socket.default_value if alpha_socket is not None and not alpha_socket.is_linked else 1.0
+
     base_color_socket = gltf2_blender_get.get_socket(blender_material, "Base Color")
     if base_color_socket is None:
         base_color_socket = gltf2_blender_get.get_socket(blender_material, "BaseColor")
@@ -57,7 +60,7 @@ def __gather_base_color_factor(blender_material, export_settings):
     if not isinstance(base_color_socket, bpy.types.NodeSocket):
         return None
     if not base_color_socket.is_linked:
-        return list(base_color_socket.default_value)
+        return list(base_color_socket.default_value)[:3] + [alpha]
 
     texture_node = __get_tex_from_socket(base_color_socket)
     if texture_node is None:
@@ -85,7 +88,7 @@ def __gather_base_color_factor(blender_material, export_settings):
                       .format(multiply_node.name))
         return None
 
-    return list(factor_socket.default_value)
+    return list(factor_socket.default_value)[:3] + [alpha]
 
 
 def __gather_base_color_texture(blender_material, export_settings):
diff --git a/io_scene_gltf2/blender/imp/gltf2_blender_pbrMetallicRoughness.py b/io_scene_gltf2/blender/imp/gltf2_blender_pbrMetallicRoughness.py
index 00bd08d2..deb9e301 100755
--- a/io_scene_gltf2/blender/imp/gltf2_blender_pbrMetallicRoughness.py
+++ b/io_scene_gltf2/blender/imp/gltf2_blender_pbrMetallicRoughness.py
@@ -233,7 +233,7 @@ def base_color(
         base_color_factor = [1, 1, 1, 1]
 
     if base_color_texture is None and not mh.vertex_color:
-        color_socket.default_value = base_color_factor
+        color_socket.default_value = base_color_factor[:3] + [1]
         if alpha_socket is not None:
             alpha_socket.default_value = base_color_factor[3]
         return
@@ -242,10 +242,7 @@ def base_color(
     needs_color_factor = base_color_factor[:3] != [1, 1, 1]
     needs_alpha_factor = base_color_factor[3] != 1.0 and alpha_socket is not None
     if needs_color_factor or needs_alpha_factor:
-        # For now, always create the color factor node because the exporter
-        # reads the alpha value from here. Can get rid of "or needs_alpha_factor"
-        # when it learns to understand the alpha socket.
-        if needs_color_factor or needs_alpha_factor:
+        if needs_color_factor:
             node = mh.node_tree.nodes.new('ShaderNodeMixRGB')
             node.label = 'Color Factor'
             node.location = x - 140, y
@@ -255,7 +252,7 @@ def base_color(
             # Inputs
             node.inputs['Fac'].default_value = 1.0
             color_socket = node.inputs['Color1']
-            node.inputs['Color2'].default_value = base_color_factor
+            node.inputs['Color2'].default_value = base_color_factor[:3] + [1]
 
         if needs_alpha_factor:
             node = mh.node_tree.nodes.new('ShaderNodeMath')