Release 1.3.9 (26.30.29)

[leaheleo]

Read the previous release notes here

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Summary

Hello and happy preview day 🥳! We are now on Release 1.3.9 (26.30.29), as of Wednesday, May 19th, 2026.

As a reminder of Editor API support:

• Editor Extensions overview article and API reference documentation on learn.microsoft.com
• Starter Kit: Contains the compiler tools and various libraries required to get started making Editor Extensions
• Samples created by our team to jump-start your own Extension creations

Additionally, if you're new to the Editor GitHub this week, we encourage you to join the Bedrock Add-Ons Discord #Editor channel!

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Custom Mesh Tool

• Added the Custom Mesh tool to Editor, allowing creators to import STL mesh files and place them as blocks

custom-mesh.mp4

Custom Dimensions and Biome Data Assignment

• Added Dimensions and Biome Data Assignment tools

new-dimension.mp4

biome-data-assignment.mp4

Full Change Log

• Added a modal dialog to Vibrant Visuals that allows users to map per-biome lighting configurations, letting creators assign specific lighting groups, atmospheric scattering, color grading, water, and cubemap settings to individual biomes

• Updated editor tools to show a load/busy mouse cursor during longer-running operations (shape placement, flood apply, chunk operations).

• Modifying buttons in a button pane now works correctly again

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Thank you for being here! You're the best! ❤️

[ciosciaa]

Biome data assignment is great!