Recognize a certain configuration of nodes as inverting Y for normals

Models made for DirectX treat the normal map values as having positive
Y pointing toward the bottom of the image, which is opposite to what my
engine and Blender expect.  This allows fixing that without modifying
the original texture.

diff --git a/blender/io_mspgl/export_material.py b/blender/io_mspgl/export_material.py
index 10be7dcba60057665792b7291ab550122901e3e7..1323737f9b8f3c48c6ac5dfa0a4f188fb63b7adc 100644 (file)
--- a/blender/io_mspgl/export_material.py
+++ b/blender/io_mspgl/export_material.py
@@ -50,7 +50,7 @@ class MaterialExporter:
                                if p.texture:
                                        tex_name = p.texture.image.name+".tex2d"
                                        if tex_name not in resources:
-                                               resources[tex_name] = texture_export.export_texture(p.texture, p.tex_usage)
+                                               resources[tex_name] = texture_export.export_texture(p.texture, p.tex_usage, invert_green=p.invert_green)
 
                                        samp_name = sampler_export.get_sampler_name(p.texture)
                                        if samp_name not in resources:

diff --git a/blender/io_mspgl/export_texture.py b/blender/io_mspgl/export_texture.py
index 6ec13eadc583ff680495451609b25651bc173f1c..8e3872b5c8646f1084c83324b73f15499c9d9e9a 100644 (file)
--- a/blender/io_mspgl/export_texture.py
+++ b/blender/io_mspgl/export_texture.py
@@ -15,6 +15,12 @@ def pixels_to_rgb(pixels):
                yield int(pixels[i+1]*255)
                yield int(pixels[i+2]*255)
 
+def pixels_to_rgb_invert_green(pixels):
+       for i in range(0, len(pixels), 4):
+               yield int(pixels[i]*255)
+               yield 255-int(pixels[i+1]*255)
+               yield int(pixels[i+2]*255)
+
 def pixels_to_gray(pixels):
        for i in range(0, len(pixels), 4):
                yield int((pixels[i]+pixels[i+1]+pixels[i+2])*255/3)
@@ -23,7 +29,7 @@ class TextureExporter:
        def __init__(self):
                self.inline_data = True
 
-       def export_texture(self, tex_node, usage='RGB'):
+       def export_texture(self, tex_node, usage='RGB', *, invert_green=False):
                image = tex_node.image
                from .datafile import Resource, Statement, Token
                tex_res = Resource(image.name+".tex2d", "texture2d")
@@ -37,7 +43,7 @@ class TextureExporter:
 
                from .util import basename
                fn = basename(image.filepath)
-               if not self.inline_data and fn:
+               if not self.inline_data and not invert_green and fn:
                        srgb = "_srgb" if colorspace=='sRGB' else ""
                        tex_res.statements.append(Statement("external_image"+srgb, fn))
                else:
@@ -56,6 +62,8 @@ class TextureExporter:
                                texdata = encode_pixels(pixels_to_rgba(pixels))
                        elif usage=='GRAY':
                                texdata = encode_pixels(pixels_to_gray(pixels))
+                       elif invert_green:
+                               texdata = encode_pixels(pixels_to_rgb_invert_green(pixels))
                        else:
                                texdata = encode_pixels(pixels_to_rgb(pixels))
                        tex_res.statements.append(Statement("raw_data", texdata))

diff --git a/blender/io_mspgl/material.py b/blender/io_mspgl/material.py
index e69cab844e3f2aa7cb4649eca55e2291e3da922f..cadfe75e09b5ef4589da97a5e99c8caec34e3538 100644 (file)
--- a/blender/io_mspgl/material.py
+++ b/blender/io_mspgl/material.py
@@ -8,6 +8,33 @@ def get_linked_node_and_socket(node_tree, socket):
                        return (l.to_node, l.to_socket)
        return (None, None)
 
+def check_group(node_tree, group, func):
+       output = group.node_tree.nodes["Group Output"]
+       from_node, _ = get_linked_node_and_socket(group.node_tree, output.inputs[0])
+       if from_node:
+               from_node, _ = func(group.node_tree, from_node)
+               if from_node and from_node.type=='GROUP_INPUT':
+                       return get_linked_node_and_socket(node_tree, group.inputs[0])
+       return (None, None)
+
+def check_invert_green(node_tree, node):
+       if node.type=='GROUP':
+               return check_group(node_tree, node, check_invert_green)
+       elif node.type!='COMBRGB':
+               return (None, None)
+
+       green, g_sock = get_linked_node_and_socket(node_tree, node.inputs["G"])
+       if not green or green.type!='MATH' or green.operation!='SUBTRACT':
+               return (None, None)
+       green, g_sock = get_linked_node_and_socket(node_tree, green.inputs[1])
+
+       red, r_sock = get_linked_node_and_socket(node_tree, node.inputs["R"])
+       blue, b_sock = get_linked_node_and_socket(node_tree, node.inputs["B"])
+       if not red or red.type!='SEPRGB' or blue!=red or green!=red:
+               return (None, None)
+
+       return get_linked_node_and_socket(node_tree, red.inputs["Image"])
+
 class MaterialProperty:
        def __init__(self, keyword, tex_keyword, value):
                self.keyword = keyword
@@ -15,6 +42,7 @@ class MaterialProperty:
                self.value = value
                self.texture = None
                self.tex_usage = None
+               self.invert_green = False
 
        def set_from_input(self, node_tree, input_socket, alpha_socket=None):
                if self.keyword:
@@ -33,6 +61,10 @@ class MaterialProperty:
                                usage = None
                                if from_node.type=='NORMAL_MAP':
                                        from_node, _ = get_linked_node_and_socket(node_tree, from_node.inputs["Color"])
+                                       invert, _ = check_invert_green(node_tree, from_node)
+                                       if invert:
+                                               from_node = invert
+                                               self.invert_green = True
                                        usage = 'RGB'
                                elif from_node.type=='RGBTOBW':
                                        from_node, _ = get_linked_node_and_socket(node_tree, from_node.inputs["Color"])