Our past few updates have been relatively minor releases. They’ve focused on fixing bugs and stability issues, and aside from a few minor features, haven’t introduced anything new. Fixing these issues is extremely important, but for those users who hadn’t experienced any problems, these updates weren’t the most exciting.

But now we’re getting back up to speed after some good time off post-Steam release. Alpha 17 will be the first major release since Alpha 16 at the end of August, and we’re excited to begin showing off some of the bigger projects we’ve been working on.

At this time we can’t say for sure which features will make it into Alpha 17. Some will be implemented only in their early stages, and others will likely have to wait until later updates. These disclaimers aside, here are a few of the things which you can look forward to in Alpha 17 and beyond:

1. Rewritten Stellar Evolution & Classification

Previously there were 5 star types in Universe Sandbox ². Now, with the rewrite, there will be 16. The improved stellar evolution model is now primarily a function of metallicity, and will work for types outside of main-sequence stars.

The result will be more dynamic and accurate properties for stars, as well as smoother transitions from type to type. The model also will now account for mass loss from solar winds. It may take a bit of time to fully incorporate all of the changes, but now that Jenn has added in these new, robust evolution models, many new possibilities await.

2. More Planetary Details

Random planets in Universe Sandbox ² are going to be visually more detailed and responsive to interactions, all part a project which we are internally calling “automata.”

In the beginning, this will work alongside our climate component to increase the spatial resolution. That is, instead of having one point of data for an object’s property, like temperature, there will now be a 2D grid of data. In the example of temperature, this means that collisions can impact values locally, so heat spreads from the impact site rather than just raising the overall temperature. In turn, this will make for much more dynamic visuals.

This higher resolution of data will also apply to elevation, influencing water levels, pressure, and material states. Further down the line this could open up doors for better surface deformation and shaping, and even set up the groundwork for basic life evolution. It’s a very exciting project, but also highly experimental: it’ll be a work-in-progress for some time to come, even when it first shows up in an update, and we can’t say for sure what it’ll eventually be able to do.

3. Better Star Glows & Rendering

This one mostly speaks for itself. Star glows and rendering are going to look a whole lot better, with smoother fading and fewer clipping issues. Georg hopes to eventually add a little coronal animation, too.

4. Back-End Changes to the User Interface

Chris is busy porting over the current custom user interface to use Unity’s user interface system. At first this may fall into the category of “Not Too Exciting For Most Users,” as it won’t involve any design changes, but this rewrite of the user interface is going to make possible a handful of things for Universe Sandbox ² further down the line. Essentially, it’s future-proofing.

The biggest advantage of this is the support for multiple character sets and a scalable interface. This translates into support for languages using non-Roman characters, and an interface that works on non-standard resolutions, such as 4k or mobile. And while a mobile version of Universe Sandbox ² is not coming any time soon, should we eventually decide to take that path, this change will make it all the more feasible. Feel free to also use this as evidence that we are not planning on wrapping up development in the near future.

5. Native Physics Code

Alpha 15 introduced Thomas’s rewrite of the physics component in Universe Sandbox ², which made everything run a whole lot faster. That was only the first part. This second part is implemented as native code, versus the previously implemented managed code. Without getting too technical, this essentially removes a step from the process, making it run a bit faster. There will be more performance improvements to come after native implementation, but this one is a big step.

After all of this is firmly in place, then it’s time for VR… But that’s a blog post for another day.

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Steam Early Access Release

After nearly 4 years of development, Universe Sandbox ² is now on Early Access and available for purchase directly through the Steam Store.

Buy Universe Sandbox ² on Steam.

Today also marks the release of another big update, Alpha 16. If you already own Universe Sandbox ², just run Steam to download the latest version.

What’s New in Alpha 16

What’s new in Alpha 16? We’ve re-enabled and improved saving and loading and completely rewrote the rendering backend to implement logarithmic z-buffering, which addresses graphical issues and paves the way for some big visual changes.

We also made further improvements to the interface and fixed a bunch of bugs and stability issues.

Let us know what you think of Alpha 16 using the in-game feedback or our forums, Facebook, or Twitter.

Or if you’ll be at PAX Prime later this week in Seattle, Washington, stop by the Indie MEGABOOTH to say hello. The whole team will be there showing off the latest and best Universe Sandbox ² and celebrating our release on Steam. We look forward to all that is still to come.

The Z-Fighting Problem

Z-fighting is a graphical issue which occurs when a game tries to draw two layers at the same depth.

The results vary — sometimes one layer can appear to poke through another or they will flicker back and forth as they “fight” over which one should be drawn in front and which one in back.

Z-fighting demonstration from Wikipedia article

From the Teapot to the Milky Way

If you’re a gamer, you’ve probably seen z-fighting before. But this issue mostly affects games which are working with very large camera distances. For example, open-world games may try to draw mountains and clouds in the distance, but because they both are designated as “very far away,” they fight over which is drawn in front.

Universe Sandbox ² handles camera distances on a scale even larger than this. The camera may be a few meters away from a teapot, and lightyears away from a galaxy. And somewhere in between there may be a whole bunch of planets. The issue here would be distinguishing which planet should be drawn in front when, relatively, they’re much closer to each other than they are to either the teapot or the galaxy.

Log-Z

This is where logarithmic z-buffering comes in. In non-technical terms, log-z is a programming technique which opens up more “options” at which layers can be drawn. For example, instead of all planets being grouped together at depth 5, they can be drawn at 5 as well as 5.1 and 5.2 and so on. And with their own personal space, they no longer fight!

Here’s a great interactive example of logarithmic versus standard z-buffering: http://threejs.org/examples/webgl_camera_logarithmicdepthbuffer.html

Using this technique in Universe Sandbox ² has been a long time coming — its implementation had been held up by a bug in Unity (the engine we use for development), which has now been fixed.

It won’t be an obvious change for users, but now that Georg has added it in, we’re ready to move forward with a whole bunch of other visual improvements as well, not to mention the small performance increase we expect.

Thanks, Georg! Now there’ll be no more of this:

You can buy Universe Sandbox ² now for instant access to the alpha via our website: universesandbox.com/2 

Universe Sandbox ² will be on Steam Early Access later this summer.