Update for 2019.2

Updates to editor version 2019.2.2f1 and ARFoundation version 2.1.3.

STW 2019.1

This release adds AR support. It uses ARFoundation to allow the player to place a game instance in the real world (a tabletop works best) and play it through touch screen controls.

Refer to the readme for instructions on how to compile for AR vs VR.

Some notes on this leg of the project:

• Updating the project from 2018.3.0b3 to 2019.1.0b7 was generally smooth.
• There was a breaking change in LWRP between those versions, which is to be expected since LWRP is still experimental/in preview. I resolved this by removing the LWRP package and reverting the few materials in the project to the standard shader.
• LWRP was removed from this project as ARFoundation is being updated to work with the latest version of its APIs. When that version of the package comes out, LWRP should be stable with ARFoundation into the forseeable future.
• Encapsulating all of the game logic into a prefab was necessary to make it placeable and to enable AR controls. To achieve this end input was converted to an event-driven model. Managers were also converted from singletons to be accessible from GameManager.cs, which remains a static singleton. If multiple games were to be placed in AR then accessing the game manager will need to be done in a different way.
• In order to spawn a prefab with a navmesh on it, it was necessary to use https://github.com/Unity-Technologies/NavMeshComponents
• NavMeshAgents have an enforced minimum radius of 0.05 in the Navigation editor. In order to get the game instance small enough, it became necessary to scale the AR Rig, which is the GameObject containing ARSessionOrigin. This workaround enforces a global scaling, which introduces a "gotcha" into the workflow. I am working with a member of the AR team now to identify the best workflow for this situation, and to see if we can lower the minimum NavMeshAgent radius to accomodate this use case.
• Daydream was showing funky patterns where geometry was meeting. This was fixed by deepening the depth buffer at ProjectSettings->Player->XRSettings->VirtualRealitySDKs->Daydream->DepthFormat.

Room for improvement:

• Originally I had intended to allow multiple instances of the game to be placed, and to enable "focus" to shift between them. I ran out of time for that, so it may be the purview of a future STW.
• You can only place the game once. Enabling re-placement would be cool. It might "just work" or it might require a navmesh reload. Again, I ran out of time.
• There is some nice setup UI in the arfoundation-samples project (https://github.com/Unity-Technologies/arfoundation-samples). It would be nice to integrate that.

STW 2018.3

This release is the produce of a Scenario Test Week for version 2018.3. It targets 2018.3.0b3.

Includes capability to support OpenVR, Oculus Desktop, WindowMR Immersive HMDs, Oculus mobile, and Daydream.