The Spatial Thermometer and XL Islands

This page describes how memory usage is managed in the XL starter islands.

You now have the opportunity to make larger games and experiences, by choosing one of the new XL islands when you start:

  • XL Flatgrid

  • XL Archipelago

  • XL Mountain Ridge

  • XL Mountain Ridge Empty

These islands are much, much bigger than the other [starter islands]. See the image below for a size comparison.

XL Island Compared to Starter Island

Starter island on the right, XL island on the left

Spatial Thermometer

These larger islands use a lot more memory, so they use a different system for handling memory and restricting how many things you can place on the island. You can place a lot more on an XL island, as long as any one area has about the same memory use as a normal-sized island.

Previously, starter islands worked by loading everything into memory and keeping it there all the time. Now all islands, regardless of size, use the Spatial Thermometer system for managing memory. With this system, islands will only use memory to hold things that are seen and used. It removes unused or unseen props and geometry from memory. As players move around the island, the system loads things into memory that the players can see and interact with.

Prop and Device Memory

The Spatial Thermometer breaks an island down into a grid of cells. Each prop you place has a memory cost that affects the area around it, within a specific radius. When you place a prop, its memory cost is added to all the cells around it from which it can be seen.

When you add a device to the island, its memory cost is added to all cells in the island. Devices always need to be loaded in memory to operate and can't be swapped in and out like props. That's because devices affect players no matter where they are on the island, and you don't want them to stop working when players get too far away from them.

When you place a prop or device, the memory usage is shown by a colored circle around the item when you are previewing it before placing it. That colored circle shows how placing that prop or device will affect the memory in that area.

The islands use two methods to let you know how much memory you have used:

  • The Cell Memory Used Bar

  • The Heat Map

Cell Memory Used Bar

When you place a prop, the Cell Memory Used Bar displays memory usage for the cell with the highest memory use within range of the spot where you place the prop. This shows the highest effect that placing the prop will have on memory use nearby. If you do not have a prop in hand, the Cell Memory Used Bar will show values for the cell with the highest memory cost on your island.

The Cell Memory Used Bar

Heat Map

The Heat Map shows you a color-coded representation of the cells on your island. You can see this information in the minimap for cells nearby, or for the whole island by opening the Map screen.

Heat Map Shown on Map Screen

The colors on the cells give you an idea of the amount of memory that each cell is currently using.

  • Blue: 0% memory used

  • Green: 25% memory used

  • Yellow: 50% memory used

  • Orange: 75% memory used

  • Red (with an exclamation point in the cell): 90% memory used. The cell is close to being over budget.

  • Red (with a padlock icon in the cell): 100% memory used. The cell is over budget and needs to have its memory reduced.

A Heat Map Showing Locked Cells

If you have reached the memory use limit in any cell on your island (cells with a padlock icon), you won't be able to place more objects in that cell's area. You need to reduce the memory usage for those locked cells before you can place any more objects in their range. You also won't be able to place devices anywhere on the island until the memory usage is reduced.

Heat Map With Cells Locked and Over Budget Warning

If you have any locked cells, you will not be able to start your game, or publish your island, until you have reduced the overall memory usage enough to unlock the cells.

Tips for reducing memory in cells:

  • You can remove props from the cell itself to reduce its memory use.

  • You can look for densely-packed cells nearby, and delete props from those to reduce the memory cost of the over-budget cell.

  • You can delete some devices, since those contribute memory use to every cell on the island.