Editing live on the device has never been easier, for fast iteration time and the ultimate in “what you see is what you get”.  For more info check out this video, the forum thread or just read some of the other entries on this blog!

This means it doesn’t use the built-in Unity inspectors or any custom inspectors you may have created, so when you click on, say, a Camera object you see the public and serialised fields of the Camera type rather than what Unity’s built-in CameraEditor inspector would have shown.

I would like to fix this and use the built-in inspectors and I have actually prototyped it extensively but it turns out there are several problems. To use the built-in inspectors we require a proxy GameObject that represents the selected object on the server. The idea is that whenever we receive a message from the server, we create a new proxy GameObject, dynamically add all components to it, and for each component, create an Editor instance with Editor.CreateEditor(component). When drawing the UI for the components, we just call Editor.OnInspectorGUI for each one and use BeginChangeCheck/EndChangeCheck to determine if anything changed. If fields have changed we send a message to the server to update it.

There are a couple of problems with this approach. The built-in inspectors cause undo events to be added to the system, but those undo events are undesirable; the GameObject is a temporary proxy object for which we don’t want to track undo events. In fact the object is not visible in the scene, so the undo events seem spurious to the user. It’s not a good user experience to generate all these undo events that go nowhere.

Another problem is that EndChangeCheck doesn’t detect that changes have happened when certain fields are changed. One such field that I found was the camera mask property. It seems to be something to do with the EditorGUI.PropertyField, which doesn’t seem to set GUI.changed to true.

The last major problem is with the proxy GameObject. We create a new proxy every time we receive a message from the server, but destroying the previous one seems to cause the Editor objects that we created to throw NullReferenceExceptions when you hit play or when Unity reloads assemblies, when it tries to reinitialise its serializedObject field. I think I need to find a way to clear the reference on the Editor when destroying the GameObject, but it wasn’t possible when I last investigated. I can’t just leave the proxy object; that’s a memory leak!

I have a Trello roadmap board with some features I’d like to add. Some are wishlist features which may not really be possible without digging into the Unity source (e.g. hotswapping prefabs, or the aforementioned built-in inspectors). One feature I would like to add is an extensible console system, where you can hook in your own commands to control the game remotely. That way you can add debug features to the game that you can then control from Unity.

Get in touch if you have any questions or feature requests for Hdg Remote Debug!

That’s the theory, anyway. A lot of people have complaints about the Unity Remote, saying that it doesn’t work very well or at all.

I’ve always felt that Unity should have a live debug view of the game running on the device that shows you all the GameObjects and their components and serialised fields. I imagined it would look like the regular built-in hierarchy and inspector windows, except it would be pulling the data via a network connection from the live build. A lot of AAA engines have a live update feature like this but Unity has nothing.

In 2014 I started work on a tool to do just this. I built an initial prototype with plans to sell it on the asset store. But then contracting jobs got in the way, and I put the project on hold. Late last year my contract work dried up, and I decided it was time to get back to it and finish it off, so I’ve spent the last four months working on it. It’s now working pretty well:

You can sit in Unity, bring up the Remote Debug window, connect to your device, and see what’s happening on it, just as though you were looking at a build running in the editor. It’s really easy to iterate on things on the device, and I’ve found it especially useful for tweaking touch controls.

Currently it requires Unity 5.3.2f1 or better because I’m using the new Scene.GetRootGameObjects API that was added. I can make it work in previous versions of Unity but with some unfortunate side effects depending on what API I use. If I use Object.FindObjectsOfType I can’t get inactive objects. There is also Resources.FindObjectsOfType but it returns all objects including resources that were manually loaded from the Resources directory. I think I can filter these out, but it just means the server is a bit more costly in terms of memory and CPU. This is something I want to do though because it would be great to provide versions of the tool for Unity 5.x across the board.

I’ve made a thread on the Unity forums about Hdg Remote Debug. If you want more information feel free to post there or email us here at Horse Drawn HQ. The tool should be going live on the asset store in the next couple of weeks.