add shader.name check

Assets/VRM/UniGLTF/Scripts/IO/MaterialExporter.cs

@@ -1,8 +1,5 @@
-using System;
+using UniGLTF.UniUnlit;
-using System.Collections.Generic;
-using UniGLTF.UniUnlit;
 using UnityEngine;
-using UnityEngine.Rendering;
 
 
 namespace UniGLTF
@@ -185,7 +182,7 @@ namespace UniGLTF
 
         static void Export_TextureTransform(Material m, glTFTextureInfo textureInfo, string propertyName)
         {
-            if( textureInfo != null && m.HasProperty(propertyName))
+            if (textureInfo != null && m.HasProperty(propertyName))
             {
                 var offset = m.GetTextureOffset(propertyName);
                 var scale = m.GetTextureScale(propertyName);
@@ -202,6 +199,21 @@ namespace UniGLTF
             }
         }
 
+        public static bool UseUnlit(string shaderName)
+        {
+            switch (shaderName)
+            {
+                case "Unlit/Color":
+                case "Unlit/Texture":
+                case "Unlit/Transparent":
+                case "Unlit/Transparent Cutout":
+                case "UniGLTF/UniUnlit":
+                    return true;
+            }
+            return false;
+
+        }
+
         protected virtual glTFMaterial CreateMaterial(Material m)
         {
             switch (m.shader.name)

Assets/VRM/UniVRM/Scripts/Format/VRMExportSettings.cs

@@ -112,10 +112,35 @@ namespace VRM
                 yield return Validation.Error("ReduceBlendshapeSize is need VRMBlendShapeProxy, you need to convert to VRM once.");
             }
 
-            if (Source.GetComponentsInChildren<Renderer>().All(x => !x.gameObject.activeInHierarchy))
+            var renderers = Source.GetComponentsInChildren<Renderer>();
+            if (renderers.All(x => !x.gameObject.activeInHierarchy))
             {
                 yield return Validation.Error("No active mesh");
             }
+
+            var materials = renderers.SelectMany(x => x.sharedMaterials).Distinct();
+            foreach (var material in materials)
+            {
+                if (material.shader.name == "Standard")
+                {
+                    // standard
+                    continue;
+                }
+
+                if (MaterialExporter.UseUnlit(material.shader.name))
+                {
+                    // unlit
+                    continue;
+                }
+
+                if (VRMMaterialExporter.VRMExtensionShaders.Contains(material.shader.name))
+                {
+                    // VRM supported
+                    continue;
+                }
+
+                yield return Validation.Warning(string.Format("unknown material '{0}' is used. this will export as `Standard` fallback", material.shader.name));
+            }
         }
 
         public void InitializeFrom(GameObject go)

Assets/VRM/UniVRM/Scripts/Format/VRMMaterialExporter.cs

@@ -101,7 +101,7 @@ namespace VRM
         }
 
         #region CreateFromMaterial
-        private static readonly string[] VRMExtensionShaders = new string[]
+        public static readonly string[] VRMExtensionShaders = new string[]
         {
             "VRM/UnlitTransparentZWrite",
             "VRM/MToon"