[1.0] TextureTransformBind の Scale/Offset 変換

Assets/UniGLTF/Runtime/UniGLTF/IO/MaterialIO/MaterialExporter.cs

@@ -206,7 +206,7 @@ static void Export_TextureTransform(Material m, glTFTextureInfo textureInfo, str
             {
                 var offset = m.GetTextureOffset(propertyName);
                 var scale = m.GetTextureScale(propertyName);
-                offset.y = 1.0f - offset.y - scale.y;
+                (scale, offset) = TextureTransform.VerticalFlipScaleOffset(scale, offset);
 
                 glTF_KHR_texture_transform.Serialize(textureInfo, (offset.x, offset.y), (scale.x, scale.y));
             }

Assets/UniGLTF/Runtime/UniGLTF/IO/MaterialIO/TextureTransform.cs

@@ -0,0 +1,22 @@
+
+
+using UnityEngine;
+
+namespace UniGLTF
+{
+    public static class TextureTransform
+    {
+        /// <summary>
+        // UV Coordinate Conversion: glTF(top-left origin) to Unity(bottom-left origin)
+        /// https://github.com/vrm-c/UniVRM/issues/930
+        /// offset.y = 1.0f - offset.y - scale.y;
+        /// </summary>
+        /// <param name="s"></param>
+        /// <param name="o"></param>
+        /// <returns></returns>
+        public static (Vector2, Vector2) VerticalFlipScaleOffset(Vector2 s, Vector2 o)
+        {
+            return (new Vector2(s.x, s.y), new Vector2(o.x, 1.0f - o.y - s.y));
+        }
+    }
+}

Assets/UniGLTF/Runtime/UniGLTF/IO/TextureIO/GltfTextureImporter.cs

@@ -118,9 +118,7 @@ public static (Vector2, Vector2) GetTextureOffsetAndScale(glTF_KHR_texture_trans
                     scale = new Vector2(textureTransform.scale[0], textureTransform.scale[1]);
                 }
 
-                // UV Coordinate Conversion: glTF(top-left origin) to Unity(bottom-left origin)
-                // Formula: https://github.com/vrm-c/UniVRM/issues/930
-                offset.y = 1.0f - offset.y - scale.y;
+                (scale, offset) = TextureTransform.VerticalFlipScaleOffset(scale, offset);
             }
 
             return (offset, scale);

Assets/UniGLTF/Samples/ScreenSpace/ScaleOffset.cs

@@ -0,0 +1,51 @@
+using UnityEngine;
+
+namespace UniGLTF.Samples
+{
+    /// <summary>
+    /// ScaleOffset の検証
+    /// </summary>
+    public class ScaleOffset : MonoBehaviour
+    {
+        [SerializeField]
+        public Vector2 Scale = Vector2.one;
+
+        [SerializeField]
+        public Vector2 Offset = Vector2.zero;
+
+        [SerializeField]
+        Material Unity;
+
+        [SerializeField]
+        Material Gltf;
+
+        void OnValidate()
+        {
+            Execute();
+        }
+
+        // Update is called once per frame
+        void Update()
+        {
+            Execute();
+        }
+
+        const string PROP_NAME = "_MainTex";
+
+        void Execute()
+        {
+            if (Unity == null || Gltf == null)
+            {
+                return;
+            }
+
+            Unity.SetTextureScale(PROP_NAME, Scale);
+            Unity.SetTextureOffset(PROP_NAME, Offset);
+
+            var (s, o) = TextureTransform.VerticalFlipScaleOffset(Scale, Offset);
+
+            Gltf.SetTextureScale(PROP_NAME, s);
+            Gltf.SetTextureOffset(PROP_NAME, o);
+        }
+    }
+}