# CesiumJS 1.146: Tab freezes/crashes when rendering ~25 buildings as voxel-style grids (per-floor coloring and picking)

**URL:** <https://community.cesium.com/t/cesiumjs-1-146-tab-freezes-crashes-when-rendering-25-buildings-as-voxel-style-grids-per-floor-coloring-and-picking/47567>\
**Category:** CesiumJS\
**Created:** [October 14, 2026, 6:24am UTC](https://community.cesium.com/t/cesiumjs-1-146-tab-freezes-crashes-when-rendering-25-buildings-as-voxel-style-grids-per-floor-coloring-and-picking/47567 "2026-10-14T06:24:37Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![Masum\_Billah](https://sea2.discourse-cdn.com/cesium/user_avatar/community.cesium.com/masum_billah/32/10449_2.png) [@Masum\_Billah](https://community.cesium.com/u/Masum_Billah)\
**Post date:** [October 14, 2026, 6:24am UTC](https://community.cesium.com/t/cesiumjs-1-146-tab-freezes-crashes-when-rendering-25-buildings-as-voxel-style-grids-per-floor-coloring-and-picking/47567/1 "2026-10-14T06:24:37Z")

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Hello Everyone,

I am building a CesiumJS application that visualizes building floors as voxel-style grids, and the viewer crashes when I draw around 25 buildings at the same time. I would appreciate your advice on the best way to structure this.

ENVIRONMENT

- CesiumJS version: 1.146
- Browser / OS: Chrome 130 / Windows 11
- GPU: Asus Ryzen 7
- Framework: plain JS

WHAT I AM DOING  
For each building, I take its footprint polygon (lon/lat), convert it to a local ENU frame, and sample a regular grid of cells (voxelSize = 2 m) inside the polygon. For every cell on every floor I create a Cesium.GeometryInstance using a shared BoxGeometry (voxelSize \* 0.98 by 0.98 by floorHeight \* 0.98) and a per-instance modelMatrix. All instances for a building go into a single Cesium.Primitive with:

- PerInstanceColorAppearance({ translucent: true, closed: true })
- asynchronous: false
- per-instance color with alpha 0.25
- a unique id object per instance ({ floor, x, y })

I color each floor by hue and recolor an entire floor when the user clicks it, using per-floor bookkeeping of the instance ids.

THE PROBLEM  
With a small number of buildings, it works, but at ~25 the tab freezes, and the viewer crashes [frozen tab]

MY QUESTIONS

1. What is the recommended approach for rendering many building floors with per-floor coloring and picking at this scale?
2. Is VoxelPrimitive appropriate for this use case, and what practical limits (dimensions, number of primitives, metadata channels) should I stay within for around 25 simultaneous volumes?
3. If I keep the geometry-based approach, what is the best way to reduce cost with many translucent boxes (merging, batching, or alternative appearances)?
4. Are there best practices for creating and destroying many primitives to avoid GPU memory growth or WebGL context loss?
5. Is there a better pattern, such as 3D Tiles or instanced models, for large numbers of repeated box-like cells?

I would appreciate your help.