Update UniGLTF. Add sparse accessor experiment to VRMExporter

Scripts/Format/VRMExporter.cs

@@ -16,7 +16,13 @@ namespace VRM
         {
             var gltf = new glTF_VRM();
             gltf.asset.generator = string.Format("UniVRM-{0}.{1}", VRMVersion.MAJOR, VRMVersion.MINOR);
-            using (var exporter = new VRMExporter(gltf))
+            using (var exporter = new VRMExporter(gltf)
+            {
+#if VRM_EXPORTER_USE_SPARSE
+                // experimental
+                UseSparseAccessorForBlendShape=true
+#endif
+            })
             {
                 _Export(gltf, exporter, go);
 

Scripts/Format/VRMImporter.cs

@@ -78,8 +78,8 @@ namespace VRM
 
         public static CreateMaterialFunc GetMaterialFunc(List<glTF_VRM_Material> materials)
         {
-            var CreateDefault = gltfImporter.CreateMaterialFuncFromShader(Shader.Find("VRM/UnlitTexture"));
-            var CreateZWrite = gltfImporter.CreateMaterialFuncFromShader(Shader.Find("VRM/UnlitTransparentZWrite"));
+            var CreateDefault = gltfImporter.CreateMaterialFuncFromShader(new ShaderStore("VRM/UnlitTexture"));
+            var CreateZWrite = gltfImporter.CreateMaterialFuncFromShader(new ShaderStore("VRM/UnlitTransparentZWrite"));
             CreateMaterialFunc fallback = (ctx, i) =>
             {
                 var vrm = ctx.GLTF as glTF_VRM;