Merge pull request #2242 from KhronosGroup/RGB2BW_socket

Fix #2176 - convert RGB 2 BW for float socket when possible

addons/io_scene_gltf2/blender/exp/material/extensions/gltf2_blender_image.py

@@ -25,6 +25,7 @@ class Channel(enum.IntEnum):
     G = 1
     B = 2
     A = 3
+    RGB2BW = 4
 
 # These describe how an ExportImage's channels should be filled.
 
@@ -41,6 +42,17 @@ def __init__(self, image: bpy.types.Image, tile, src_chan: Channel):
         self.tile = tile
         self.src_chan = src_chan
 
+class FillImageRGB2BWTile:
+    """Fills a channel from a Blender UDIM image, RGB 2 BW"""
+    def __init__(self, image: bpy.types.Image, tile):
+        self.image = image
+        self.tile = tile
+
+class FillImageRGB2BW:
+    """Fills a channel from a Blender image, RGB 2 BW"""
+    def __init__(self, image: bpy.types.Image):
+        self.image = image
+
 class FillWhite:
     """Fills a channel with all ones (1.0)."""
     pass
@@ -124,6 +136,12 @@ def fill_image(self, image: bpy.types.Image, dst_chan: Channel, src_chan: Channe
     def fill_image_tile(self, image: bpy.types.Image, tile, dst_chan: Channel, src_chan: Channel):
         self.fills[dst_chan] = FillImageTile(image, tile, src_chan)
 
+    def fill_image_bw(self, image: bpy.types.Image, dst_chan: Channel):
+        self.fills[dst_chan] = FillImageRGB2BW(image)
+
+    def fill_image_bw_tile(self, image: bpy.types.Image, tile, dst_chan: Channel):
+        self.fills[dst_chan] = FillImageRGB2BWTile(image, tile)
+
     def store_data(self, identifier, data, type='Image'):
         if type == "Image": # This is an image
             self.stored[identifier] = StoreImage(data)
@@ -213,7 +231,7 @@ def __encode_happy_tile(self, export_settings) -> bytes:
         return self.__encode_from_image_tile(self.fills[list(self.fills.keys())[0]].image, export_settings['current_udim_info']['tile'], export_settings)
 
     def __unhappy_is_udim(self):
-        return any(isinstance(fill, FillImageTile) for fill in self.fills.values())
+        return any(isinstance(fill, FillImageTile) or isinstance(fill, FillImageRGB2BWTile) for fill in self.fills.values())
 
 
     def __encode_unhappy_udim(self, export_settings) -> bytes:
@@ -222,7 +240,7 @@ def __encode_unhappy_udim(self, export_settings) -> bytes:
 
         images = []
         for fill in self.fills.values():
-            if isinstance(fill, FillImageTile):
+            if isinstance(fill, FillImageTile) or isinstance(fill, FillImageRGB2BWTile):
                 if fill.image not in images:
                     images.append((fill.image, fill.tile))
                     export_settings['exported_images'][fill.image.name] = 2 # 2 = partially used
@@ -273,6 +291,8 @@ def __encode_unhappy_udim(self, export_settings) -> bytes:
                     out_buf[int(dst_chan)::4] = tmp_buf[int(fill.src_chan)::4]
                 elif isinstance(fill, FillWith):
                     out_buf[int(dst_chan)::4] = fill.value
+                elif isinstance(fill, FillImageRGB2BWTile) and fill.image == image:
+                    out_buf[int(dst_chan)::4] = tmp_buf[0::4] * 0.2989 + tmp_buf[1::4] * 0.5870 + tmp_buf[2::4] * 0.1140
 
         tmp_buf = None  # GC this
 
@@ -288,7 +308,7 @@ def __encode_unhappy(self, export_settings) -> bytes:
         # Find all Blender images used
         images = []
         for fill in self.fills.values():
-            if isinstance(fill, FillImage):
+            if isinstance(fill, FillImage) or isinstance(fill, FillImageRGB2BW):
                 if fill.image not in images:
                     images.append(fill.image)
                     export_settings['exported_images'][fill.image.name] = 2 # 2 = partially used
@@ -321,6 +341,8 @@ def __encode_unhappy(self, export_settings) -> bytes:
                     out_buf[int(dst_chan)::4] = tmp_buf[int(fill.src_chan)::4]
                 elif isinstance(fill, FillWith):
                     out_buf[int(dst_chan)::4] = fill.value
+                elif isinstance(fill, FillImageRGB2BW) and fill.image == image:
+                    out_buf[int(dst_chan)::4] = tmp_buf[0::4] * 0.2989 + tmp_buf[1::4] * 0.5870 + tmp_buf[2::4] * 0.1140
 
         tmp_buf = None  # GC this
 

addons/io_scene_gltf2/blender/exp/material/gltf2_blender_gather_image.py

@@ -22,7 +22,7 @@
 from ....io.com import gltf2_io_debug
 from ....io.exp.gltf2_io_user_extensions import export_user_extensions
 from ..gltf2_blender_gather_cache import cached
-from .extensions.gltf2_blender_image import Channel, ExportImage, FillImage, FillImageTile
+from .extensions.gltf2_blender_image import Channel, ExportImage, FillImage, FillImageTile, FillImageRGB2BW
 from .gltf2_blender_search_node_tree import get_texture_node_from_socket, detect_anisotropy_nodes
 
 @cached
@@ -173,7 +173,7 @@ def __gather_name(export_image, use_tile, export_settings):
 
         imgs = []
         for fill in export_image.fills.values():
-            if isinstance(fill, FillCheck):
+            if isinstance(fill, FillCheck) or isinstance(fill, FillImageRGB2BW):
                 img = fill.image
                 if img not in imgs:
                     imgs.append(img)
@@ -296,7 +296,12 @@ def __get_image_data_mapping(sockets, results, use_tile, export_settings) -> Exp
                 elif socket.socket.name == 'Occlusion':
                     src_chan = Channel.R
                 elif socket.socket.name == 'Alpha':
-                    src_chan = Channel.A
+                    # For alpha, we need to check if we have a texture plugged in a Color socket
+                    # In that case, we will convert RGB to BW
+                    if elem.from_socket.type == "RGBA":
+                        src_chan = Channel.RGB2BW
+                    else:
+                        src_chan = Channel.A
                 elif socket.socket.name == 'Coat Weight':
                     src_chan = Channel.R
                 elif socket.socket.name == 'Coat Roughness':
@@ -338,9 +343,15 @@ def __get_image_data_mapping(sockets, results, use_tile, export_settings) -> Exp
 
             if dst_chan is not None:
                 if use_tile is None:
-                    composed_image.fill_image(result.shader_node.image, dst_chan, src_chan)
+                    if src_chan == Channel.RGB2BW:
+                        composed_image.fill_image_bw(result.shader_node.image, dst_chan)
+                    else:
+                        composed_image.fill_image(result.shader_node.image, dst_chan, src_chan)
                 else:
-                    composed_image.fill_image_tile(result.shader_node.image, export_settings['current_udim_info']['tile'], dst_chan, src_chan)
+                    if src_chan == Channel.RGB2BW:
+                        composed_image.fill_image_bw_tile(result.shader_node.image, export_settings['current_udim_info']['tile'], dst_chan)
+                    else:
+                        composed_image.fill_image_tile(result.shader_node.image, export_settings['current_udim_info']['tile'], dst_chan, src_chan)
 
                 # Since metal/roughness are always used together, make sure
                 # the other channel is filled.
@@ -357,7 +368,7 @@ def __get_image_data_mapping(sockets, results, use_tile, export_settings) -> Exp
 
     # Check that we don't have some empty channels (based on weird images without any size for example)
     keys = list(composed_image.fills.keys()) # do not loop on dict, we may have to delete an element
-    for k in [k for k in keys if isinstance(composed_image.fills[k], FillImage)]:
+    for k in [k for k in keys if isinstance(composed_image.fills[k], FillImage) or isinstance(composed_image.fills[k], FillImageRGB2BW)]:
         if composed_image.fills[k].image.size[0] == 0 or composed_image.fills[k].image.size[1] == 0:
             export_settings['log'].warning("Image '{}' has no size and cannot be exported.".format(
                                              composed_image.fills[k].image))