I tried to get a single Unity project to build for multiple platforms over the weekend. The code I’m writing is probably best suited to a flat screen with mouse and keyboard quite honestly. That said, I’m interested in working with VR systems and thus intend it to run on the platforms that I have available. This gives me:

• Flat screen with keyboard and mouse.
• Google Daydream VR with Daydream controller.
• HTC Vive with two Vive controllers
• Possible Google cardboard with no controller (perhaps a game controller as a stretch?).

Multiple Platforms from One Project

Sam had run across a couple of projects that claimed to work across platforms last week and sent me a link. Over the weekend I pulled the projects down and ran them on the Daydream without problems. They were a bit awkward to use as neither of them used the daydream controller effectively (one seemed to be built as a cardboard app, using the sight axis for selection).

I took the project that had been targeted on the Daydream and re-targeted it to the PC with a Vive headset attached. I got errors (don’t have the exact form) that suggested that I needed to load the Steam VR SDK in order to make things work. In the end I loaded the SDK from the asset store. This did allow the Vive headset to connect but did not display the information panels that the project was designed to show. At that point I shelved the project…I’ll probably return at some point to look deeper into the implementation, but for now I’ve had enough.

Switching Platforms in a Project (the hard way)

Later in the weekend I tried simply creating a project with a few simple assets and adding in the two SDKs. I was able to get the Daydream up and running (tried that first) by making the usual additions to the scene for that SDK and setting up the platform. To get the Vive running I had to delete all of the Daydream items from the scene and add in the usual Vive content. That too worked as expected.

The surprise came when I switched back to Daydream again. I continued to get errors indicating that the Vive input mapper json file was missing. It appears that something Vive related was still attached to the project and looking for Vive specific assets. This is another area where I may dig deeper at some point. For the moment I’m moving on.

Modular and Layered

I did dig through a good bit of content over the weekend (both video and online blogs/documentation) that suggested Unity supports external code assemblies linked in. This leads me down the road to a more modular approach.

• Provide multiple .NET core assemblies that aren’t Unity specific code to implement the ‘business logic’ of the game. This keeps the complex code (game rules, world generation and storage) and other such items in a place where they can be unit tested and managed as pure code assemblies.
• Manage all Unity assets that aren’t target specific in free-standing packages that get bolted into a target specific frame at the last moment.
• Build the SDK specific parts of the game as thin wrappers over these other assets. These will be asset packages and projects that contain only target specific items and user facing elements.

I’m going to head down this road next and try structuring a new version of my Cluster game to support this approach. I started coding up the game generation part on Sunday and will likely try bolting a version of that into a VR frame as soon as it is complete enough to be usable.

A quick perusal of the documentation suggests that I’m going to need a better grasp of the unity event system to get my handling of VR controller raycasting working as I’d like.

My stars (and anything else that wants to be responsive) will need to handle input events and thus detect when a ray touches the construct (and stops touching it). This should allow me to do the sort of ‘hover text’ I want. I’ll likely try to work this up tonight and get my inflating stars code working with the DayDream (and perhaps the Vive as well).

I’m still wishing for a decent solution to modularity that would let me keep the common assets between the three platforms I’m interested in separate enough to make sharing them easy.

I’m currently maintaining three divergent versions of the code and assets with each configured for a different system. As the game rules implementation develops, this is going to become hard to support.

I just pushed an update to github that detects mouse over of stars in the game screen and temporarily bumps the size of the star up by a factor of eight (to show you pointed at it). I’ve also got some other minor bits working such as finding a script on an object given the GameObject .

I need to add code to read in the star names file. I also want to make the DayDream pointer do this same thing to stars you point at. In the longer run, I expect to add a UI panel that displays additional information about the star when you point at it and may very well magnify the size of the star and any associated information at the same time.

Now on to seeing what I can see with DayDream…

Now I’m stitching in some game logic and properties related to game play. Still need to get the systems loaded from the static stuff I’ve added and start building some game play but it feels like things are moving at a decent clip.

I’m also going to be looking at keeping some of the game logic in external, non-game assemblies. Being able to pull in external code that can be unit tested and perhaps even deployed in other areas is useful.

Hoping to get the basics wired in and then get back to interface work. I need to get the VR controls started. A user should be able to switch perspectives between several fixed camera spots with the controller. They need to be able to get a basic view of the state of the board from a distance and be able to view full details of a given star by pointing their controller at it.

• View basic star information available to a given player from a distance.
• Assemble a fleet (if fleet markers are available) from ships present at a star.
• Task an existing fleet with going to another system.
• Allocate this turn’s production to construction or research.
• Side effect of the above, move population from a planet surface to colony transports.
• Check transit time from one star system to another.
• See beacon area of effect for your existing beacons.