Roblox Forum

Quick Summary

• Custom Terrain Materials left Early Access on October 22, 2026, and are now fully supported for publishing
• You can define up to 62 paintable terrain materials in a single place, each with its own color tint or MaterialVariant texture
• Enabling Expanded Terrain in Workspace properties swaps the terrain backend, so the place has to reopen before the change applies
• The first terrain optimizations cut CPU memory overhead by 90 percent and meshing latency by 45 percent in Roblox's own benchmark
• Thin terrain below 16 voxels, MaterialVariant physical properties, and Team Create editing still carry known issues

What changed on October 22, 2026

Roblox announced that Custom Terrain Materials and the first terrain performance improvements have exited Early Access. That is the meaningful part for most builders: you no longer need to sign up for a testing program, and you can publish a place that uses these features and anyone on Roblox can play it.

Before this, the only way to get custom terrain materials was to join the Terrain Early Access Program, which opened in June 2026. Early access came with a warning the announcement repeated more than once: places you saved while in the program were unplayable for anyone not in the program, and Team Create collaborators who were not in the program could not open the place at all. That restriction is what made it a bad idea to test on a live game. Now that the feature is fully supported, that caution no longer applies.

If you edited a place while you were in Early Access, Roblox says the custom materials might show up as grass unless you re-enable everything through the Workspace properties. The fix is the same one you use for a fresh place.

How to enable Expanded Terrain

Expanded Terrain is off by default and it is set per place, not per account. Enabling it swaps the terrain backend, so the place has to reopen for the change to take effect.

1. Update Studio and restart it. The setting does not appear until you do.
2. Open the place where you want the feature.
3. Select Workspace in the Explorer.
4. In the Properties panel, change Expanded Terrain from Default to Enabled.
5. Save the place, close it, and reopen it.

For a brand new place, Studio saves and closes the place for you when you enable the feature, but you still have to reopen it yourself before the new material slots are usable. For a Team Create place, the restart prompt is not enough. Roblox says to exit the place and wait about 15 seconds before reopening it, otherwise the changes do not apply.

Creating custom terrain materials

You build the materials from the Terrain Editor's material picker, not from a separate tool.

1. Open the Terrain Editor and pick a brush such as Paint, Draw, Fill, or Sculpt.
2. Open the material picker next to Source Material.
3. Click the plus icon to create a new terrain material.
4. Choose a name and a base material. You can attach a MaterialVariant for custom textures, or adjust the Color to tint it.
5. Paint, draw, fill, or sculpt with the material you just created.

The Replace tool accepts custom terrain materials too, which lets you swap one material for another across a whole region without touching the rest of the terrain. That is the fastest way to restyle an existing map.

Custom terrain materials also support multiple color variations of the same base. Before this system, a MaterialVariant used as an override replaced one base material globally across the entire place. Now you can paint five different shades of grass in one map instead of being stuck with one.

Material overrides versus custom terrain materials

This is the part that trips people up, because both features solve a similar problem and they behave very differently.

• A material override maps one custom material onto every instance of a base material in the place, terrain included. It is global and it is all or nothing.
• Custom terrain materials let you paint several distinct materials and shades onto terrain within one place. That is the feature you want for biome variety.
• MaterialVariant and SurfaceAppearance both use PBR textures. MaterialVariant is for reusable tileable material and carries physical properties. SurfaceAppearance is for a specific mesh with UV mapping and has no physical properties.
• Custom physical properties on a MaterialVariant are not respected by the custom terrain material slots yet, according to the official documentation.

If you need different terrain colors in different areas of one map, custom terrain materials are the answer. If you want one material to replace every instance of Grass everywhere, the override is the simpler tool.

The performance numbers worth knowing

The optimization work matters as much as the materials for anyone building a large map. Terrain used to be stored directly in the place file, and it was the classic way to blow past the 100 MB publishing limit. Roblox moved terrain onto its asset platform so it no longer counts against your place file the way it used to.

From the Early Access announcement, the before and after figures:

• Total place file size: 23 MB before, 430 KB after ejection
• Deserialization time: 9.3 seconds before, 7.3 seconds after
• Meshing end to end latency: 30.62 ms before, 16.57 ms after
• CPU memory overhead: 352 MB before, 35 MB after

The full launch announcement rounds those results up differently, describing a 90 percent reduction in CPU memory overhead and a 45 percent reduction in meshing latency in one benchmark. Both sets of numbers come from Roblox, and the second is the one tied to the October 22 launch. The Early Access post also quoted a 40 to 60 percent reduction in client memory use, twice as fast terrain loading, and terrain stored on the asset platform so it does not bloat the place file.

Treat these as Roblox's own benchmarks rather than a guarantee for your place. Your results will depend on map size, how much of the map is terrain, and how many of the 62 material slots you actually fill.

What changed since Early Access

Roblox shipped a batch of fixes based on tester feedback:

• Added sorting to the quick context menu
• Synced material selection between the Terrain Materials Manager and the Terrain Editor brush
• Fixed the color picker to close correctly when you click away to another screen
• Updated windows to resize properly to your device's screen
• Moved the Terrain Materials Manager out of the Studio ribbon and into the Window, then 3D menu. You can still open it by right-clicking a material in the Terrain Editor material picker.

The manager move is the one you will notice first if you used the beta. The ribbon button is gone. The route now is Window, then 3D, then Terrain Material Manager.

Known issues and limitations

Roblox published the list it is still working on, plus what the documentation marks as unsupported:

• Custom physical properties on a MaterialVariant are not respected by the custom terrain material slots yet.
• Editing terrain in Team Create might introduce meshing or visual bugs.
• Heightmap and colormap import might produce different results than before. Import with a colormap is more sensitive to the colors of your materials.
• If you enable the feature in a place you have never saved to Roblox, it will not reopen automatically. Select the place from the start screen.
• Terrain thinner than 16 voxels can disappear on the client or in play mode when the streaming radius is small and streaming is enabled. Adding thickness fixes it. Roblox explicitly does not recommend thinning terrain as a memory optimization under Expanded Terrain, because it saves little or no memory.

The thin terrain issue is the one most likely to cost you time. If you build a low wall, a thin path, or a surface shell and it vanishes on some devices, the terrain is probably under 16 voxels thick. Bulk it up rather than chasing a streaming setting.

A note on the 62 versus 64 number

The original Early Access announcement in June 2026 said the program expanded the number of terrain materials you can paint from 23 to 64. The full launch announcement in October 2026 says you can define up to 62 materials. The current Creator Hub documentation, updated the same day as the launch, also says 62.

Both numbers are real and they are not a contradiction. The program description covered the expanded material slots in the backend. The shipped feature defines 62 paintable materials. If you plan a map around a material count, plan for 62, because that is the number the live documentation states today.

Should you turn this on

For a new place, yes. The material variety is the point, and the file size and memory improvements are a real gain over storing terrain in the place file.

For a live place, test in a copy first. Enabling Expanded Terrain swaps the terrain backend, and the heightmap and colormap import behavior changed. If your map relies on imported heightmaps, reimport and compare before you publish over the live version.

FAQ

How many custom terrain materials can I use?
The current documentation says up to 62 paintable materials per place. The June 2026 Early Access announcement used the number 64 when describing the expanded slots.

Do I still need to sign up for a program to use them?
No. Custom Terrain Materials left Early Access on October 22, 2026, and you can publish places that use them. Players do not need any special access to play.

Why does my terrain show as grass after I enable Expanded Terrain?
You probably edited the place while in the Terrain Early Access Program. Set Expanded Terrain to Enabled in Workspace properties, then save, close, and reopen the place.

Why did the Terrain Materials Manager move?
It was moved out of the Studio ribbon into Window, then 3D. You can also right-click a material in the Terrain Editor material picker and choose Open in Terrain Material Manager.

Can I change a material's color and have it update everywhere?
Yes. When you change a material's settings, such as its color, the update applies immediately to all terrain using that material. If you delete a material the terrain still uses, the affected terrain turns bright purple so you can find and replace it.

Why did my thin terrain disappear?
Terrain thinner than 16 voxels can vanish on the client or in play mode when the streaming radius is small and streaming is enabled. Add thickness to the terrain. Roblox does not recommend thinning terrain as a memory optimization.

Can I script the terrain materials?
Yes. The Terrain class exposes SetMaterialSlot, GetMaterialSlot, ResetMaterialSlot, and WriteVoxelChannels for configuring material slots and writing voxel data. The official announcement includes a Lua example for creating slots and writing a region.

Sources

• Roblox DevForum: Full launch of Custom Terrain Materials and performance improvements (October 22, 2026)
• Roblox DevForum: Early Access program announcement with terrain optimization benchmarks
• Roblox Creator Hub: Custom terrain materials documentation
• Roblox Creator Hub: Materials, MaterialVariant, and material overrides documentation