source/material_node_search.py

@@ -0,0 +1,114 @@
+# SPDX-FileCopyrightText: 2011-2024 Blender Foundation
+#
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+import logging
+_logger = logging.getLogger("export_x3d.material_node_search")
+
+"""
+functions implementing searching the node tree for Blender materials in search
+of particular nodes enabling export of material properties into other formats
+"""
+
+
+# node based material identifiers
+#BSDF_PRINCIPLED = 'BSDF_PRINCIPLED'
+
+# IMAGE           = 'image'
+
+# values of bl_idname for shader nodes to be located
+# reference Python API list of subclasses of ShaderNode
+# at https://docs.blender.org/api/current/bpy.types.ShaderNode.html#bpy.types.ShaderNode
+class _ShaderNodeTypes:
+    MATERIAL_OUTPUT=  "ShaderNodeOutputMaterial"
+    BSDF_PRINCIPLED = "ShaderNodeBsdfPrincipled"
+    IMAGE_TEXTURE   = "ShaderNodeTexImage"
+
+# supported values of Image Texture Node extension property
+# REPEAT="REPEAT"
+# CLIP  ="CLIP"
+
+def _find_node_by_idname(nodes, idname):
+    """
+    nodes a sequence of Nodes, idname a string
+    Each node assumed to ne an instance of Node(bpy_struct)
+    https://docs.blender.org/api/current/bpy.types.Node.html
+
+    The idname is searched for in the Node instance member bl_idname
+    https://docs.blender.org/api/current/bpy.types.Node.html#bpy.types.Node.bl_idname
+    and is generally some string version of the name of the subclass
+
+    See https://docs.blender.org/api/current/bpy.types.ShaderNode.html for list of
+    ShaderNode subclasses
+
+    if 0 targets are found, returns None
+    if 1 target is found returns that Node
+    if more than 1 targets are found prints warning string and returns first found
+    """
+    _logger.debug("enter _find_node_by_idname search for %s in %r" % (idname, nodes))
+    nodelist = [nd for nd in nodes if nd.bl_idname == idname]
+    _logger.debug("result _find_node_by_idname found %i" % len(nodelist))
+    if len(nodelist) == 0:
+        return None
+    if len(nodelist) > 1:
+        _logger.warn("_find_node_by_idname : multiple (%i) nodes of type %s found" % (len(nodelist), idname))
+    return nodelist[0]
+
+def imageTexture_in_material(material):
+    """
+    argument material an instance of Material(ID)
+    https://docs.blender.org/api/current/bpy.types.Material.html
+
+    returns instance of ShaderNodeTexImage
+    https://docs.blender.org/api/current/bpy.types.ShaderNodeTexImage.html
+    """
+    _logger.debug("evaluating image in material %s" % material.name)
+
+    material_output = _find_node_by_idname( material.node_tree.nodes, _ShaderNodeTypes.MATERIAL_OUTPUT)
+    if material_output is None:
+        _logger.warn("%s not found in material %s" % (_ShaderNodeTypes.MATERIAL_OUTPUT, material.name))
+        return None
+
+    SURFACE_ATTRIBUTE= "Surface"
+    bsdf_principled =  _find_node_by_idname(
+        [ndlink.from_node for ndlink in  material_output.inputs.get(SURFACE_ATTRIBUTE).links],
+        _ShaderNodeTypes.BSDF_PRINCIPLED)
+    if bsdf_principled is None : return None
+
+    BASE_COLOR_ATTRIBUTE      = 'Base Color'
+    image_texture = _find_node_by_idname(
+        [ndlink.from_node for ndlink in  bsdf_principled.inputs.get(BASE_COLOR_ATTRIBUTE).links],
+        _ShaderNodeTypes.IMAGE_TEXTURE )
+    if image_texture is None: return None
+    _logger.debug("located image texture node %r" % image_texture)
+    return image_texture
+
+##    x3d_supported_file_extension = {"PNG" : ".png","JPEG" : ".jpg"}
+##    if image_texture.image.file_format not in x3d_supported_file_extension:
+##        logger.warn("images of format %s not supported" % image_texture.image.file_format)
+##        return None
+##
+##    retVal = self.ImageExportRecord()
+##    retVal.image = image_texture.image
+##
+##    # ref https://docs.blender.org/api/current/bpy.types.ShaderNodeTexImage.html#bpy.types.ShaderNodeTexImage.extension
+##    x3d_supported_extension = [CLIP, REPEAT]
+##    if image_texture.extension in x3d_supported_extension:
+##        retVal.extension = image_texture.extension
+##    else:
+##        logger.warn("image_texture.extension value %s unsupported in X3D" % image_texture.extension)
+##        retVal.extension=REPEAT
+##
+##    packed_file = image_texture.image.packed_file
+##    if packed_file is not None and packed_file.size > 0:
+##        from os.path import splitext, basename
+##        name_base = splitext( basename(image_texture.image.name))[0]
+##        url_ext = x3d_supported_file_extension[image_texture.image.file_format]
+##        retVal.url =   name_base +url_ext
+##
+##    logger.info("ImageExportRecord : %s packed: %r url: %s : extension: %r" % \
+##                    (retVal.image.name, retVal.is_packed,
+##                     retVal.url , retVal.extension))
+##
+##    return retVal
+