Universe Sandbox News

Drastically increased collision fragments and framerates, overhauled planetary water distribution, plus dozens of improvements come together in Update 26.3.

[h3]Oceans Filling Like a Bathtub[/h3]
Water fills a tub from its lowest point - why not on a planet? Oceans now start at the lowest elevations and fill valleys like you would a bathtub, creating more realistic-looking continents and oceans. (Previously liquid water would “precipitate” evenly across the surface.)

[h3]Buttery Smooth Collisions & Particles Aplenty[/h3]
Major performance improvements have resulted in epic collisions with double the particles. Fragment generation is substantially more consistent across various simulation speeds. Collisions now perform much more smoothly: in many cases we’re seeing as much as triple framerate increases.

[h3]More Highlights[/h3]

• Fixed the “annoying bug” that darkened customized planet surfaces
  
• Ice & Snow, which are simulated separately, now have color options
  
• Avast, Matey! Change an object’s Sea Level in the properties panel
  
• Cleaned up the object property panel and added new action buttons
  

Please report any issues on our Steam forum, on Discord, or in-game via Home > Send Feedback.


[h2]Simulation[/h2]
[h3]New [/h3]

• “Stabilize Temperature” and “Stabilize Phase” are two new surface simulation functions in an object’s Property panel. Instantly set the temperature of the surface or the phase of the water (gas, liquid, or solid ice) to their steady state. This is useful to see how a planet will settle over time, rather than needing to speed up time.
  
• Added an editable “Sea Level” property to an object’s Surface tab. Use this to raise or lower the water level on an object’s surface by “filling up” the oceans from the bottom up. This is a much more intuitive and engaging way to add water to an object’s surface than was previously possible. Previously, water was added as a uniform sheet across the entire surface.
  
• Added a toggleable “Fusion Power” to the Simulation Settings
  

[h3]Improvements [/h3]

• Major performance and optimization improvements to surface simulation, collision heating, n-body calculations, and fragmentation. Collisions in particular perform much more smoothly than before.
  
• Improved the consistency of fragment generation during collisions at a variety of simulation speeds.
  
• Light energy is now correctly conserved when scattering off the surface of objects, resulting in more realistic, less shiny surfaces.
  
• Improved the simulation of light absorption in water, yielding darker deep water and greener shallow water
  
• Revised default water color to be a more saturated blue, reflecting how satellite photos of Earth are often represented
  
• Improved the water generation on random rocky planets, resulting in more planets with defined continents and oceans
  
• Added relativistic kinetic energy to collision calculations. Only relevant at speeds near the speed of light
  
• Revised the initial size of Earth’s ice caps
  

[h3]Fixes[/h3]

• Fixed an issue where many fragments created during a collision would immediately re-collide with the colliding object. This now results in much higher particle count in the aftermath of collisions.
  
• Fixed an issue that was causing a error in momentum transfer during collisions
  
• Fixed in issue where newly created objects could adopt surface elevation information from other objects
  
• Laser previously affected an area slightly larger than the intended size. Now the laser affects the correct area size, as designated by the visual laser tool reticle.
  
• Venus will no longer produce volatiles after opening "Planets Between Earth & Moon" sim
  
• Fixed an issue where objects could be heated prior to being added to the simulation
  
• Fixed an issue where objects could still lose mass to fragmentation with “Create Fragments” turned off
  
• Fixed an issue where the heated area on an object’s surface after a collision would jump to a different size
  
• Fixed an issue that was causing exoplanets to generate with too much water
  
• Fragments that were spawning slightly oversized are now corrected
  

[h2]User Experience[/h2]
[h3]New[/h3]

• New styling of many action buttons in an object’s Property panel
  

[h3]Improvements[/h3]

• Major improvements to saving. This should reduce the occurrence of corrupted save data, and overall improve the stability of saving and loading simulations.
  
• Zooming on surface data maps now zooms at the cursor’s position
  
• Snow is now correctly visually represented on top of ice
  
• The distance at which Surface Lock enables when moving close to an object has been revised
  
• Improved object selection logic, preventing the selection of mostly-invisible gas clouds when they are too close to the camera
  
• Improved the colorization of objects when using non-realistic Color modes
  
• Improved the visibility of the Laser tool reticle, and added a missing reticle on gas giants
  
• Improved color rendering of heated gas giants
  
• Revised styling of expanders in the Property panel
  
• Revised styling of the scrollbar on surface data views
  
• Reorganization of the Property panel Overview and Surface tab
  
• Reorganization of tabs in the Open panel, notably moving My Sims to the front
  
• Habitable zone visibility can now be toggled by the hotkey H, which is editable in the keybinds.
  
• Removed the English-only abbreviations from non-English languages that could sometimes cause awkward translations. Cleaned up the abbreviations used in English.
  

[h3]Fixes[/h3]

• Fixed the behavior of “Auto” selection in dropdown menus with auto-selecting options. “Auto” can now be correctly toggled on and off.
  
• Fixed an issue where atmospheres and clouds would be incorrectly tinted darker when customizing the underlying surface colors
  
• Fixed the sorting behavior for simulations in the Open panel
  
• Toggle buttons added to the hotbar will no longer incorrectly switch state when loading a new simulation
  
• Particles now move smoothly when exiting Chart mode
  
• Fixed an issue where an unplaced object hologram could be selectable
  
• Atlas Resolution now correctly resets to default when all settings are reset
  
• Fixed an issue where an empty sim would report having 1 object in the Stats panel
  
• Fixed an issue where Slowest Body wouldn’t be reported correctly in Simulation Settings
  
• Fixed an issue where it would be possible for the mouse wheel to zoom in Universe Sandbox while using the mouse in a different application
  
• Fixed an issue preventing Surface Lock from working during a guide
  
• Fixed an issue where the strongest attractor in a simulation could be given an orbit parent (26.3.1)
  

[h2]Content[/h2]
[h3]New[/h3]

• The color of ice and snow can now be customized in an object’s Appearance tab
  

[h3]Improvements[/h3]

• Revision to Collision simulations to ensure the impact collision consistency across various simulation speeds
  

Craters from impacts, lasting surface damage, and voluminous explosions all come together in Update 26.2 to close out the year!

[h3]Surface Damage & Craters[/h3]
Molten and heated areas on an object’s surface will appear scorched after cooling, with visible craters in the aftermath of collisions.

[h3]Explosions[/h3]
Rocky objects more accurately vaporize into hot, dense gas clouds when exploded. The simulation of gas particles, which slowly expand over time, is more realistic, and results in dramatic debris clouds after impacts. We’ve also added a Detonation Delay setting to the Explode tool.

[h3]Two-Handed Gestures in VR[/h3]
Move, scale, and rotate the universe using intuitive gestures with both hands and the grip buttons.


Please report any issues on our forum, on Discord, or in-game via Home > Send Feedback.

Check out our full list of Update 26.2 changes.

Brown Dwarf Transitions
We’ve made significant improvements to the simulated transitions of gas giants into brown dwarfs and stars, driven by a newly simulated Fusion Power energy property. Learn more about fusion power and brown dwarfs in our new guide: Guides > Science > Are Gas Giants Failed Stars?

More Color Customization
The color of water on all planets, and the color of vegetation on Earth, are now customizable via Properties > Appearance.

Laser Improvements
Laser presets have been reorganized, and we’ve added a new Push Water setting in the Laser panel. While not entirely realistic, this is a fun way to play with the water simulation on an object’s surface. Try out the “Wave Maker” laser preset to create massive waves in a planet’s oceans.

Please report any issues on our forum, on Discord, or in-game via Home > Send Feedback.

Check out our full list of Update 26.1 changes.

Update 26 brings the full Universe Sandbox desktop experience to virtual reality (VR). We redesigned the bottom bar and made visual improvements to collision fragments, rocky planets, and liquid water.

Full Desktop Experience in VR
Universe Sandbox VR now matches the desktop experience and will maintain feature parity moving forward. You can now use virtual hands to manipulate planets, edit properties, or use separate tools in each hand.

Reimagined User Interface
Featuring a customizable bottom bar, our improved user interface makes Universe Sandbox easier to use, more discoverable, and improves support for extra small screens.

Improved Visuals
Collision fragments have new, high-definition graphics and lighting. Elevation maps for rocky planets have more detail. Water graphics now show waves and better light reflection. Asteroids and collision fragments have new highly-detailed dynamic models with better lighting.

This update includes 20+ additions and 50+ fixes and improvements.

Please report any issues on our forum, on Discord, or in-game via Home > Send Feedback.

Check out our full list of Update 26 changes

[h3]New and Improved Tidal Heating
[/h3]

Our first ScienceLog explained how the flow of energy into and out of an object is responsible for heating or cooling the object. If you look at the sources of energy in a simulation, listed in the Energy Flow section of the object’s Surface tab, you’ll see Tidal Power listed. Unlike some of the other heat sources, like stars or impacts, tidal heating originates inside the object itself.

Tidal heating has been a part of Universe Sandbox for some time, but after the release of our new Surface Grids feature in Update 24, we noticed that tidal heating wasn’t changing the temperature of planets the way we expected. We traced this unusual behavior back to some errors in our tidal heating calculations, and then we fixed those bugs while we prepared the energy flow tools for Update 25.

Now that we’re more confident in our tidal heating simulation, we thought that for this ScienceLog, we’d dive a little deeper into tidal heating, where it comes from, and how it works in Universe Sandbox. It may not be as flashy as other heating sources, like supernovas or lasers, but tidal heating can create some unexpected and interesting effects, and even determine the habitability of a planet or moon!


[h3]What is Tidal Heating?
[/h3]

As usual, it all comes back to gravity. The force of gravity depends on the distance between objects. For example, the strength of Earth’s gravitational pull on the Moon is stronger on the side of the Moon that’s facing the Earth than on the far side of the Moon. This difference, called the tidal force, can stretch the Moon out of its normally spherical shape. If the tidal forces are strong enough, they can even rip an object apart through a process called Roche fragmentation.

Caption: Jupiter’s moon Io orbiting the gas giant in a simulation with just Jupiter and its moons. Io’s eccentric orbit creates tidal friction inside the moon, and the graph of Tidal Power on the left shows how the incoming rate of tidal energy changed over time. In real life, astronomers believe this tidal heating is the source of energy for Io’s many volcanoes.

Smaller tidal forces will leave the object intact, and the “squishing” of the object’s spherical shape is usually too small to see. But if the tidal forces change over time— say, because the object is spinning, or its orbit is non-circular (elliptical)— all this squishing and un-squishing will create friction inside the object, which will add heat energy.


[h3]How Does Tidal Heating Work in Universe Sandbox?
[/h3]

As the simulation runs, Universe Sandbox is constantly calculating the gravitational forces pulling on every object. We use these calculations to determine where each object will move next, and how fast, but we can also use them to calculate the strength of the tidal forces inside the object. If these forces are strong enough, the simulation produces fragments to simulate Roche fragmentation tearing the object apart. It also calculates how much heating is produced by tidal friction, and sends that information into the energy flow calculations that control the object’s temperature.

With the improvements in Update 25, we’re now much more confident in our tidal heating model. We even made a new simulation to show it off: A Tidally Heated Habitable Moon. This sim demonstrates a scenario predicted by some astronomers: a moon orbiting a gas giant outside of its star’s habitable zone. Normally this distance would make the moon’s surface too cold to support liquid water, but tidal forces from the gas giant heat the moon’s surface to a balmy, habitable 14.9°C.


Caption: A tidally heated habitable moon located outside of the habitable zone. The warmer surface temperature, due to tidal heating, allows liquid water to flow on this moon.

Try creating your own tidal heating simulations, and experiment with the masses and orbits of objects (especially the orbital eccentricity) to see how these properties affect the amount of tidal power added to an object. Can you make a habitable moon or planet outside the habitable zone?

Note: You may have noticed the odd looking spike in the “Jupiter’s moon Io orbiting the gas giant” graph. One of the challenges that comes with simulating complex features like tidal heating in Universe Sandbox is that when you increase the speed of the simulation, accuracy in the calculations can decrease. These abnormalities occur because there are less points of data to reference. The graph could be smoothed out by estimating data points in between, but that would introduce inaccurate data, and we’re all about accuracy here.


This blog post is part of our ongoing series of ScienceLog articles, intended to share the science behind some of Universe Sandbox’s most interesting features. If you would love to learn about the real-life science powering our simulator, please stay tuned and let us know what you would like to read about next.

To join our community discussions, please join us on our Steam Forum and our official Discord community.