glTF importer/exporter: Manage some official Khronos Extensions about Materials

    KHR_materials_ior
    KHR_materials_sheen
    KHR_materials_specular
    KHR_materials_transmission
    KHR_materials_variants
    KHR_materials_emissive_strength
    KHR_materials_volume

Documentation update is still in progress

1 files changed, 81 insertions, 0 deletions

diff --git a/io_scene_gltf2/blender/exp/gltf2_blender_gather_materials_clearcoat.py b/io_scene_gltf2/blender/exp/gltf2_blender_gather_materials_clearcoat.py
new file mode 100644
index 00000000..65c164b4
--- /dev/null
+++ b/io_scene_gltf2/blender/exp/gltf2_blender_gather_materials_clearcoat.py
@@ -0,0 +1,81 @@
+# SPDX-License-Identifier: Apache-2.0
+# Copyright 2018-2022 The glTF-Blender-IO authors.
+
+import bpy
+from io_scene_gltf2.io.com.gltf2_io_extensions import Extension
+from io_scene_gltf2.blender.exp import gltf2_blender_get
+from io_scene_gltf2.blender.exp import gltf2_blender_gather_texture_info
+
+def export_clearcoat(blender_material, export_settings):
+    clearcoat_enabled = False
+    has_clearcoat_texture = False
+    has_clearcoat_roughness_texture = False
+
+    clearcoat_extension = {}
+    clearcoat_roughness_slots = ()
+
+    clearcoat_socket = gltf2_blender_get.get_socket(blender_material, 'Clearcoat')
+    clearcoat_roughness_socket = gltf2_blender_get.get_socket(blender_material, 'Clearcoat Roughness')
+    clearcoat_normal_socket = gltf2_blender_get.get_socket(blender_material, 'Clearcoat Normal')
+
+    if isinstance(clearcoat_socket, bpy.types.NodeSocket) and not clearcoat_socket.is_linked:
+        clearcoat_extension['clearcoatFactor'] = clearcoat_socket.default_value
+        clearcoat_enabled = clearcoat_extension['clearcoatFactor'] > 0
+    elif gltf2_blender_get.has_image_node_from_socket(clearcoat_socket):
+        fac = gltf2_blender_get.get_factor_from_socket(clearcoat_socket, kind='VALUE')
+        # default value in glTF is 0.0, but if there is a texture without factor, use 1
+        clearcoat_extension['clearcoatFactor'] = fac if fac != None else 1.0
+        has_clearcoat_texture = True
+        clearcoat_enabled = True
+
+    if not clearcoat_enabled:
+        return None, None
+
+    if isinstance(clearcoat_roughness_socket, bpy.types.NodeSocket) and not clearcoat_roughness_socket.is_linked:
+        clearcoat_extension['clearcoatRoughnessFactor'] = clearcoat_roughness_socket.default_value
+    elif gltf2_blender_get.has_image_node_from_socket(clearcoat_roughness_socket):
+        fac = gltf2_blender_get.get_factor_from_socket(clearcoat_roughness_socket, kind='VALUE')
+        # default value in glTF is 0.0, but if there is a texture without factor, use 1
+        clearcoat_extension['clearcoatRoughnessFactor'] = fac if fac != None else 1.0
+        has_clearcoat_roughness_texture = True
+
+    # Pack clearcoat (R) and clearcoatRoughness (G) channels.
+    if has_clearcoat_texture and has_clearcoat_roughness_texture:
+        clearcoat_roughness_slots = (clearcoat_socket, clearcoat_roughness_socket,)
+    elif has_clearcoat_texture:
+        clearcoat_roughness_slots = (clearcoat_socket,)
+    elif has_clearcoat_roughness_texture:
+        clearcoat_roughness_slots = (clearcoat_roughness_socket,)
+
+    use_actives_uvmaps = []
+
+    if len(clearcoat_roughness_slots) > 0:
+        if has_clearcoat_texture:
+            clearcoat_texture, clearcoat_texture_use_active_uvmap, _ = gltf2_blender_gather_texture_info.gather_texture_info(
+                clearcoat_socket,
+                clearcoat_roughness_slots,
+                export_settings,
+            )
+            clearcoat_extension['clearcoatTexture'] = clearcoat_texture
+            if clearcoat_texture_use_active_uvmap:
+                use_actives_uvmaps.append("clearcoatTexture")
+        if has_clearcoat_roughness_texture:
+            clearcoat_roughness_texture, clearcoat_roughness_texture_use_active_uvmap, _ = gltf2_blender_gather_texture_info.gather_texture_info(
+                clearcoat_roughness_socket,
+                clearcoat_roughness_slots,
+                export_settings,
+            )
+            clearcoat_extension['clearcoatRoughnessTexture'] = clearcoat_roughness_texture
+            if clearcoat_roughness_texture_use_active_uvmap:
+                use_actives_uvmaps.append("clearcoatRoughnessTexture")
+    if gltf2_blender_get.has_image_node_from_socket(clearcoat_normal_socket):
+        clearcoat_normal_texture, clearcoat_normal_texture_use_active_uvmap, _ = gltf2_blender_gather_texture_info.gather_material_normal_texture_info_class(
+            clearcoat_normal_socket,
+            (clearcoat_normal_socket,),
+            export_settings
+        )
+        clearcoat_extension['clearcoatNormalTexture'] = clearcoat_normal_texture
+        if clearcoat_normal_texture_use_active_uvmap:
+            use_actives_uvmaps.append("clearcoatNormalTexture")
+
+    return Extension('KHR_materials_clearcoat', clearcoat_extension, False), use_actives_uvmaps
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