Fix model asset thumbnail if mesh is not centered around origin

Source/Editor/Content/Proxy/ModelProxy.cs

@@ -72,7 +72,10 @@ namespace FlaxEditor.Content
         {
             if (_preview == null)
             {
-                _preview = new ModelPreview(false);
+                _preview = new ModelPreview(false)
+                {
+                    ScaleToFit = false,
+                };
                 InitAssetPreview(_preview);
             }
 
@@ -91,6 +94,7 @@ namespace FlaxEditor.Content
             _preview.Model = (Model)request.Asset;
             _preview.Parent = guiRoot;
             _preview.SyncBackbufferSize();
+            _preview.ViewportCamera.SetArcBallView(_preview.Model.GetBox());
 
             _preview.Task.OnDraw();
         }