Cesium for Omniverse v0.25.0

Cesium for Unity Samples v1.20.0

CesiumJS 1.136

User Stories

CesiumJS forms the foundation of Virtual City Systems’ open, scalable urban planning tools. Virtual City Systems (VCS) has built its modular software suite around CesiumJS to help cities across Europe visualize, analyze, and manage urban spaces in 3D.

Potential future development in Berlin, Germany, shown as architectural data surrounded by a 3D mesh of existing buildings. Courtesy Virtual City Systems.

VCS, a Cesium Certified Developer, is committed to advancing open tech ecosystems for municipal planning and administration. They were one of the first companies to help promote 3D Tiles as an OGC community standard, and they released VC Map as open source in 2021. This move accelerated adoption and empowered cities to customize and extend the platform freely.

3D visualization of a weather sensor in Memmingen, Germany, along with its real-time temperature and humidity data. Courtesy Virtual City Systems.

A web-based urban twin viewer powered by CesiumJS, VC Map is at the heart of VCS's platform. Cesium allows VC Map to render their users’ large-scale geospatial datasets—terrain, CityGML models, mesh data, and point clouds—efficiently into the browser, enabling smooth, interactive city models for strategic planning and public engagement. VC Map offers both high performance and long-term digital sovereignty for governments.

“With Cesium, we can visualize massive, complex urban datasets responsively and intuitively—and build custom tools on top of a robust, well-supported platform. As a Cesium Certified Developer, we’re proud to promote Cesium as a foundation for transparent, standards-based 3D solutions in the public sector.”

 – Claus Nagel, Managing Director & CTO, Virtual City Systems

3D visualization of environmental effects of planned buildings in Rosenheim, Germany, showing nighttime wind speeds (left) and summer heat stress (right). Courtesy Virtual City Systems.

VC Map can be extended with a number of modular software solutions. One of the most compelling is VC Solar, a 3D solar potential analysis tool. Built on CesiumJS, VC Solar allows both professionals and citizens to explore rooftop solar viability in 3D.

Measuring solar potential in Lüdenscheid, Germany. This visualization uses color on CityGML buildings to visualization annual global radiation. Users can select a single surface to view a graph showing monthly irradiation. Courtesy Virtual City Systems.

Users can assess energy yield, CO₂ savings, and financial feasibility using VCS’s custom sun model and ray-tracing algorithms. These calculations can be run citywide in the backend or interactively in the browser thanks to Cesium’s efficient rendering and extensibility.

Analyzing solar potential in the municipality of Vaterstetten, Germany, with the VC Solar App. Courtesy Virtual City Systems.

VC Solar, developed by Virtual City Systems and built on CesiumJS, allows both professionals and citizens to explore rooftop solar viability in 3D

VC Solar

Virtual City Systems is able to deliver high-performance 3D visualization and extensibility because of Cesium’s commitment to openness. Whatever your industry, CesiumJS gives you the foundation to create scalable, transparent, and customizable solutions. Explore bringing 3D visualizations in the browser to your users with open source CesiumJS, and learn more about our open standards work.

Virtual City Systems Advocates Open Source for Urban Digital Twins

To modernize defense planning and rehearsal, VRAI used Cesium for Unreal to build the Virtual All-Domain Environment (VADE), enabling users to deeply examine areas of interest before arriving. 

VADE uses Cesium to mirror operational reality. Courtesy VRAI. 

Virtual All-Domain Environment (VADE) uses Cesium to mirror operational reality. Courtesy VRAI.

This Is VADE

An immersive XR platform in the works since 2021, VADE began as a proof of concept between simulation data company VRAI and the Royal Air Force for comprehensive situational awareness and could scale across Defence. VRAI announced VADE’s full release at DSEI in fall 2025. 

Real-world 3D data and live collaboration in VADE enable a common operating picture (COP) for detailed planning and faster decisions. Add XR, and troops familiarize themselves with a location before deploying. VADE can be set for individuals or in multiplayer mode, accessed via desktop app or with headsets.  

The tool’s capabilities span domains: 

For drone intervisibility studies, users can draw routes, mark waypoints at each kilometer, and determine blind spots at specific locations and heights to ensure proper placement anywhere on the globe.  

With a volumetric tool for battlespace management and deconfliction, airspace coordination via VADE is accurate and intuitive.  

High-altitude parachute insertion simulations include trackback lines for descent, giving the distance to the drop zone throughout the line; users can view the line from the aircraft or the ground, with the surroundings they can expect to see.  

Because VADE allows users to customize for NATO standards, slopes turn red if they’re not sufficient for helicopter landing sites (HLS). 

Although VADE is not a targeting tool, users can examine the impacts of explosives. 

Restricted operating zone for UAS overwatch. Courtesy VRAI.

Intervisibility study to ensure proper placement. Courtesy VRAI.

Route planning, with directional arrows and optional kilometer markers. Courtesy VRAI.

Gun target line (GTL) tool. Courtesy VRAI.

GTL and impact of explosives. Courtesy VRAI.

VADE employs Cesium World Terrain and Bing Maps Aerial imagery with Cesium for Unreal to enable users to navigate to places that matter for their missions, manipulating the time of day and simulating weather conditions, with high-fidelity rendering. When users are online, they can pull in Google Photorealistic 3D Tiles for exercises in urban areas, and Vexcel data is a boon when VADE is used as part of an airgapped solution via Cesium ion Self-Hosted.  

The VADE library includes data via Cesium ion; 3D models of aircraft, tanks, and other vehicles; NATO map marking symbols for friendly forces and enemy capabilities; and user-specific sources, like their own imagery, photogrammetry, or GitHub repos. VADE connects to users’ private Cesium ion accounts for hosting, tiling, and streaming efficiently. Using geospecific data via Cesium saves VRAI engineers and their users days of work per location and obviates the need for hand modeling or geotypical data, improving situational awareness and decision speed and reducing the cognitive burden on those tasked with complex planning and rehearsal. 

“It’s a transformative way of planning for defense. We operate in multiple dimensions—why wouldn’t we plan in multiple dimensions?” said Ant Casson, former Squadron Commander in the Royal Air Force and VRAI’s business development lead for the UK and Europe. “The possibilities are endless for VADE, enabled by the powerful tools provided by Cesium for Unreal.”

The VADE library includes 3D models of aircraft, tanks, and other vehicles. Courtesy VRAI.

VADE is dual use: in addition to its defense value, the app’s live 3D COP enables better decisions with real data for emergency services, disaster relief, critical national infrastructure planning, large event planning, and agricultural monitoring.  

Learn to integrate 3D geospatial data when clarity, confidence, and speed matter most. 

VRAI Delivers Virtual All-Domain Environment with Cesium for Unreal 

When a court case following a serious automobile accident could benefit from a visualization of the incident, attorneys turn to Forensic Rock, a Philadelphia company that creates visualizations of accident scenes using tire marks, LiDAR scans, and other physical evidence. With Google Photorealistic 3D Tiles and Cesium for Unreal, Forensic Rock delivers immersive, accurate reconstructions with speed and precision.

Forensic Rock recreates accident scenes for court cases using Photorealistic 3D Tiles and Cesium for Unreal. Courtesy Forensic Rock.

Visualizing car accidents using Cesium for Unreal

Forensic Rock

In one urgent case, Forensic Rock animators were given only two weeks to reconstruct an accident. They completed their animation on time thanks to Cesium for Unreal.

Forensic Rock’s typical process is to complete a LiDAR scan of the site, then build the scene and add an animation of the circumstances of the accident. By using Cesium for Unreal, they were able to forgo the labor intensive scanning and modeling stage. Through Cesium ion, animators had instant access to curated global datasets, including Photorealistic 3D Tiles, which gave them the real-world terrain and building data from the exact crash location needed for the scene.

With Photorealistic 3D Tiles, Forensic Rock can focus on visualizations without losing time to scanning and modeling the environment. Courtesy Forensic Rock.

Using Photorealistic 3D Tiles from the exact location of the accident, as well as police report data about the vehicle’s speed and position, they plotted a point-to-point crash trajectory that clearly demonstrated the path of the accident. The result was a compelling, data-driven animation that attorneys could use in court.

“While the forensics business often presents stressful deadlines, the integration of Cesium into our pipeline ensures we are always prepared.” 

Because Cesium is built around open standards, animators have access to high-quality datasets like Photorealistic 3D Tiles to bridge the gap between raw data and visual storytelling—making their work not just technically impressive but also impactful in legal contexts. Sign up for a Cesium ion account to bring real-world datasets into your application.

Forensic Rock Accelerates Accident Reconstruction with Google Photorealistic 3D Tiles

ガーナとトリニダード・トバゴにおけるAI都市再構成とCesiumによる3D可視化

2025年、国連宇宙部（UNOOSA）と英連邦事務局が共同で推進する「Commonwealth Digital Twin Project」において、Cesiumが重要な役割を果たしました。本プロジェクトは、気候変動の影響を受けやすい英連邦諸国を対象に、AIと衛星データによる3D都市モデルと洪水・高潮シミュレーションを構築し、住民の防災力を高める国際的な試みです。

洪水リスクが高い2カ国を対象に

初期対象として選ばれたのは、西アフリカのガーナとカリブ海のトリニダード・トバゴ。いずれも近年洪水被害のリスクが高まっており、かつ現地政府や関連機関が協力的であったことから選定されました。今後は、同様の課題を抱える他の英連邦諸国にも水平展開が想定されています。

AIで生成された都市モデル × 国連防災シミュレーション

このプロジェクトでは、日本のスタートアップ企業SpaceData社が、Vantor社（旧Maxar社）の高解像度衛星画像（30cm級）を用い、AIによる自動処理によってLOD1〜LOD3レベルの都市モデルを生成しました。これにより、空港や港など主要なインフラのデジタルツインが構築され、洪水や高潮による災害シミュレーションも実装されました。一方、洪水・高潮の影響評価には、国連宇宙部の国連防災緊急対応衛星情報プラットフォーム（UN-SPIDER : the United Nations Platform for Space-based Information for Disaster Management and Emergency Response）の技術監督のもと、災害シミュレーションとガーナ及びトリニダード・トバゴのステークホルダーへの展開が実施されました。今後はこれらのデジタルツインを活用し、浸水シナリオに応じた避難ルートの最適化や避難建物の指定など両国の避難計画の立案や更新に寄与することが期待されます。

「使える3D」への橋渡し：東京大学・渡邊英徳研究室 Watanave Labの役割

この都市モデルや防災シナリオを、誰でもブラウザ上で閲覧・操作できる形で可視化したのがCesiumです。実際の可視化と3D Tiles変換を担ったのは、東京大学大学院 情報学環 渡邊英徳教授の研究室　Watanave Labです。

LOD付きの都市モデルを受け取った研究室では、BlenderやUnityなどの中間ツールも活用しつつ、Cesium ionによる3D Tilesへの変換を実施。その後、Cesium Stories上に成果物をまとめることで、住民・行政・研究者が“視て理解できる”デジタルツインが完成しました。

ガーナ・ジェームスタウン漁港の海面上昇による影響シミュレーション(Cesium Stories)

トリニダード・トバゴ空港における海面上昇による影響シミュレーション（Cesium Stories）

ガーナ・ジェームスタウン漁港およびトリニダード・トバゴ空港における海面上昇の様子（Cesium Stories）

SpaceData社との役割分担：処理の高度さと可視化の手軽さ

このプロジェクトの先進性は、SpaceData社の高度なAI処理能力と東京大学 Watanave LabによるCesiumを活用した手軽かつ強力な可視化機能の連携にあります。

SpaceData社の処理：光学衛星画像からAIで自動抽出、構造化されたLOD付き建物データを生成。これは属性情報付きのメタデータ構造を持ち、将来的な災害分析にも活用可能。



東京大学 Watanave Labでの処理：SpaceData社によって生成された3DデータをCesium ionで軽量な3D Tiles形式に変換・高速配信し、ブラウザだけで閲覧可能な状態に展開。さらに時間軸・シナリオ・地形・属性情報との連動も可能。



とくにCesium Storiesの機能は、技術知識がなくても地元行政や教育関係者が操作・説明できるUIを備えており、今回のような国際防災協力のビジュアル表現に最適です。

ArcGISとの役割分担と今後の展望

なお、この成果はArcGIS Onlineとのハイブリッド運用も想定されています。ArcGISは属性分析・専門的な防災解析に活用され、Cesiumはその可視化・共有・住民説明・多国間連携に最適なプラットフォームとして位置付けられています。

国連宇宙部担当者は、「今後、英連邦諸国の他地域への展開においても、このCesium + SpaceData + 東大モデルをひとつの標準構成として検討したい」と述べており、本事例はグローバル展開の第一歩となる可能性を秘めています。

この取り組みは、単なる技術実証にとどまらず、洪水など災害のリスクが高い地域に、AI・衛星・3D技術を届けるという社会的意義を持っています。

Cesiumは、今後も国際社会における現実に根ざした3D活用を支援し続けていきます。

あなたのプロジェクトにも、Cesiumを。3D都市表示、リスクの可視化、共有がすぐに始められます。是非　Cesium ionアカウントに登録してみてください。

Harnessing 3D with Cesium for Disaster Resilience: International Collaboration among the United Nations, the University of Tokyo, and SpaceData


 AI-driven urban reconstruction and 3D visualization in Ghana and Trinidad and Tobago

In 2025, Cesium played a vital role in the Commonwealth Digital Twin Project, a joint initiative led by the United Nations Office for Outer Space Affairs (UNOOSA) and the Commonwealth Secretariat. The project aims to build 3D urban models and simulate flood and sea level rise using AI and satellite data in Commonwealth countries (former British dependencies) that are especially vulnerable to climate change, helping to strengthen community-level disaster resilience.

The first countries selected for the pilot phase were Ghana in West Africa and Trinidad and Tobago in the Caribbean—both facing increasing flood risks and demonstrating strong cooperation from local governments and stakeholders. The project is expected to scale to other Commonwealth countries facing similar challenges.

AI-generated urban models + UN-based flood simulation

In this project, the Japanese startup SpaceData used Vantor (formerly Maxar Intelligence)’s high-resolution satellite imagery (approximately 30 cm) and AI-based automated processing to generate city models with levels of detail (LOD). This enabled the construction of digital twins of key infrastructure such as airports and ports, as well as the implementation of disaster simulations for flooding and storm surges.

For flood and sea level rise risk assessment, simulation was conducted by integrating the urban models with Digital Elevation Models (DEM), following methods recommended by the the United Nations Platform for Space-based Information for Disaster Management and Emergency Response (UN-SPIDER). This made it possible to identify vulnerable zones and visualize their potential impact.

From data to usable 3D: The University of Tokyo’s Watanave Lab

Cesium was used to visualize the 3D urban models and disaster scenarios in a browser-accessible, interactive format. This transformation was led by Professor Hidenori Watanave’s research lab at the University of Tokyo’s Interfaculty Initiative in Information Studies.

The lab received the LOD-structured city models, used intermediate tools such as Blender and Unity, and converted the data into 3D Tiles with Cesium ion. This conversion step was conducted entirely within Cesium ion, ensuring that the resulting tiles were optimized for web-based streaming and visualization.The results were then presented using Cesium Stories, providing a digital twin accessible to residents, government officials, and researchers.

Jamestown Fishing Harbour, Ghana, in Cesium Stories.

Airport in Trinidad and Tobago in Cesium Stories.

Visual simulations of sea level rise impact at James Town Fishing Harbour in Ghana and the airport in Trinidad and Tobago (source: UNOOSA—Cesium Stories).

SpaceData × Cesium: combining advanced processing and seamless visualization

A hallmark of this project was the seamless integration of SpaceData’s AI-powered processing and Cesium’s powerful and accessible visualization capabilities.

SpaceData: Used AI to automatically extract and generate structured building data with LOD and rich metadata from optical imagery—enabling future disaster analysis and simulation use.

Cesium: Transformed the resulting 3D data into lightweight, streamable 3D Tiles for fast web-based visualization. This includes integration with time-based scenarios, terrain models, and attribute data.

Cesium Stories were especially effective for non-technical users, enabling local governments and educators to easily interact with and explain the 3D content—ideal for use in international disaster resilience communication.

Coordination with ArcGIS and future outlook

The outcomes of this project were also designed for hybrid operation with ArcGIS Online. While ArcGIS was leveraged for attribute and technical analysis, Cesium served as the platform for public-facing visualization, sharing, civic engagement, and international collaboration.

“As we expand this initiative to other Commonwealth nations, we are considering this model—Cesium + SpaceData + University of Tokyo—as a reference configuration.”

This project may serve as a blueprint for wider global deployment.

This initiative goes beyond a mere technical demonstration—it is a socially meaningful effort to deliver satellite imagery, AI, and 3D technologies to regions facing high disaster risk.

Cesium continues to support the practical use of 3D geospatial technology to address real-world global challenges.

Just like in this project, Cesium users tackle global issues—for AI-enhanced city modeling, disaster risk visualization, or public communication.

Get started with Cesium ion to immediately build and share 3D urban visualizations, simulate disaster impacts, and collaborate across teams—all in a web browser.

Cesiumが拓く、3D可視化による防災の未来：国連・東京大学・SpaceDataの国際連携

Joey Sipos, founder of 5D Realities, develops highly immersive flight experiences for virtual reality. His flagship title Glider Sim, which is available on Steam and Meta Quest, leverages Cesium for Unity and Google Photorealistic 3D Tiles to bring the real world to life for users preparing for airborne adventures.

Flying a paramotor trike over the San Francisco Bay in Glider Sim. Courtesy 5D Realities.

In each simulation, users can choose from a variety of light aircraft, including hang gliders, paragliders, and ultralights. They can customize the time of day and wind conditions, adjust both airspeed and direction, and turn on visual cues to reveal wind patterns and thermal updrafts—a critical element in the art of gliding.

A paraglider ridge soaring on the Island of O’ahu, Hawaii. Wind particles with trails show wind currents in real time, with green indicating lift and red indicating sink. These optional visual cues are a valuable tool for learning gliding and how wind interacts with terrain. Courtesy 5D Realities.

In VR, players can use hand controllers to physically interact with the aircraft’s control surfaces—for example, grabbing and pulling the brake toggles in a paraglider. Some enthusiasts have taken the experience even further, building custom flight rigs for an ultra-realistic simulation.

Alek Jadkowski from Paraglide New England flight school using a simple hanging simulator rig for use with Glider Sim VR. Courtesy 5D Realities.

Originally, Joey manually built custom maps for iconic locations like the Tetons in Wyoming and Walenstadt, Switzerland, using elevation data and satellite imagery. After that labor-intensive process, he was thrilled to discover Cesium for Unity, which made it possible to bring the entire Earth into the simulator. Within just a couple of weeks, Joey integrated Cesium for Unity, allowing players to explore anywhere in the world.

Hang gliders ridge soaring cliffs near Marseille, France. In multiplayer mode, all user locations and weather conditions are synchronized across the entire globe. Players can navigate Earth, spot friends in real time, and instantly jump to their location. Courtesy 5D Realities.

Built on open standards and APIs, Cesium for Unity gives simulation designers access to an accurate, full-scale globe. With a Cesium ion account, Joey combines that geospatial foundation with Photorealistic 3D Tiles, which use the Open Geospatial Consortium (OGC) community standard 3D Tiles created by Cesium to efficiently stream massive amounts of 3D data.

Photorealistic 3D Tiles make Glider Sim a beautiful, accurate way to explore Earth for the casual player as well as the experienced pilot. Courtesy Joey Sipos.

GliderSim is a flight simulator with paragliders and hang gliders offering global views with Google Photorealistic 3D Tiles, developed in Cesium for Unity.

GliderSim

The app has over 5,000 users. Both new and experienced pilots can practice their technique anywhere in the world, including at real launch sites fetched from the Paragliding Earth API, allowing them to get familiar with the terrain and practice real-world scenarios such as takeoffs and landings.

Flying a hang glider in an XC (cross-country) challenge based on a real-world hang gliding competition that takes place in Mobelo, Italy. Scores are saved online and displayed in an in-game leaderboard. Courtesy 5D Realities.

Integrating Cesium has attracted a wide range of users to Glider Sim, from dedicated pilots to casual explorers. It also has allowed Joey to focus on enhancing other areas of the simulator, such as delivering a smoother multiplayer experience and introducing new features like saving and sharing favorite launch sites.

Flying an ultralight trike over the Golden Gate Bridge, California, in multiplayer mode. Courtesy 5D Realities.

With Cesium, Glider Sim is a more powerful training and practice tool, exploration platform, and global flight simulator. To bring real-world data to your simulation, check out Cesium for Unity.

Glider Sim Players Fly the World with Cesium

About 25% of the global seafloor has been mapped in high resolution, according to NOAA, leaving a lot of work to be done. It’s not always practical or safe for humans to be involved, and that’s where Terradepth comes in: its autonomous underwater vehicles collect vast amounts of 3D seabed data hosted on Cesium ion Self-Hosted and streamed to its CesiumJS-powered app, Absolute Ocean. 

Terradepth cuts the seafloor-to-browser process from weeks to days. Courtesy Terradepth.

Terradepth Absolute Ocean Platform featuring Cesium Tilers

Traditionally, sending out a crew, collecting data, manually processing it, and making it available to users took several weeks. Using machines for dangerous, repeatable work, processing and sharing data where it’s captured, and employing people for analysis cuts the seafloor-to-browser process to days. 

Terradepth has been using Cesium since Absolute Ocean’s development and release in 2022. Absolute Ocean users collect and manage their data securely so they can recognize geographic physical features, identify human-made objects like sunken wrecks or unexploded ordnance, and observe change over time beneath the waves in immersive 3D. Hydrographers in academia, infrastructure, and national security rely on this growing collection of undersea geospatial data for better, faster decisions, with nearly immediate access to interactive data instead of a static slide or hard drive transfers. 

Skellig Michael, Ireland, in Absolute Ocean. Courtesy Terradepth.

Detail in ocean data varies: 500 m resolution from satellite altimetry, 50-100 m resolution from a ship, and 5 cm resolution from a robot near the seafloor, where human safety is questionable or even impossible. Terradepth’s AUVs use multibeam sonar, magnetometers, and more to collect terabytes of data. More detail means more data, and Terradepth uses Cesium to get it to users efficiently and securely.  

With Cesium ion Self-Hosted, Terradepth stores massive point clouds, GeoTIFFs, and other data types; tiles the point clouds into 3D Tiles; and streams them to Absolute Ocean, which is built on CesiumJS, for sharing with a broad research community or smaller set of decision-makers. Cesium ion Self-Hosted enables Absolute Ocean’s processing and sharing at the edge and supports data residency requirements. In addition to its detailed seabed data, Terradepth accesses Cesium World Terrain and Bing Maps Aerial imagery for accurate geospatial context above sea level. 

“Terradepth collects terabytes of data from the ocean. The sheer size meant customers used to wait weeks or months for their data. But with Absolute Ocean using Cesium Tilers at the edge we can let them see it comparatively instantly—with an intuitive, immersive, and three-dimensional user interface,” said Andrew Lunstad, Terradepth CTO.  

Watch Andrew Lunstad's 2025 Cesium Developer Conference talk to learn more about why Terradepth deploys Cesium ion Self-Hosted.

Developers and the Open Geospatial Ecosystem

Comprehensive, collaborative seafloor data becomes insight into one of the least explored parts of our planet. 

Learn more about hosting, tiling, and streaming massive datasets in your own environment to process at the edge and meet strict security requirements.  

Terradepth Processes Seafloor Data at the Edge with Cesium ion Self-Hosted 

Large scale projects require massive coordinated efforts from many people across many businesses, whether that’s grading hundreds of acres for new suburbs, laying thousands of miles of pipelines, or hauling tens of thousands of cubic yards of dirt from quarries. Even minor errors can be costly, and sharing a common ground between the many teams involved is critical.  

Propeller supports users working at large scale sites: quarries, mines, earthworks, waste management, etc. Courtesy Propeller.

For users like these, Propeller provides the tools to perform frequent accurate drone surveys, process that data, and visualize the site. When this isn’t frequent enough, DirtMate brings near-real-time data into the mix. Propeller’s platform gives users an intuitive 3D model that’s recent, realistic, and accurate, so they can spot safety hazards, track earthworks progress, and measure reality against design plans to make calculated operational decisions around material, labor, and equipment needs. 

Propeller’s users perform drone scans of their sites and then visualize those scans in 3D with CesiumJS. Now, with support for IFC files as 3D Tiles, they’re able to compare designs against reality. Courtesy Propeller.

The heart of Propeller’s visualization is CesiumJS. Propeller was an early adopter of Cesium: for years they’ve been using Cesium’s open source software to visualize drone-captured surveys of earthworks, quarries, mines, and waste management sites. Propeller’s commitment to accuracy—reliably achieving geospatial accuracy within 3 cm—has made their platform trusted by professional surveyors. The sophisticated tooling they’ve brought into their platform, which they put into a simple form factor, makes advanced analysis accessible to anyone involved in the project, regardless of technical background.

Propeller users can see their project in accurate 3D. For pipelines, electric utilities, railways, and other long linear assets, the geospatial coordinate system in CesiumJS renders designs aligned with real-world curvature. Courtesy Propeller.

Propeller recently got an upgrade when its team incorporated Cesium’s Design Tiler into the platform. The Design Tiler takes complex BIM data, like the Industry Foundation Classes (IFC) open standard, and tiles it into 3D Tiles for efficient streaming. These improvements allow users to look at much more granular data, on a much larger scale, faster than ever.

"Integrating the Cesium Design Tiler into our platform has revolutionized our support for BIM for all our customers.” 

—Harry Morris, software engineer, Propeller

3D Tiles has made IFC files from one of the most cumbersome to one of the most performant file types on Propeller’s platform. This video shows first the original solution of an IFC model loaded in Propeller’s platform and then the same model tiled as 3D Tiles. Courtesy Propeller.

A visual of IFC files loaded in Propeller's platform before 3D Tiles and after tiling.

IFC files in Propeller before and after 3D Tiles

The tiling pipeline transformed IFC files—once cumbersome and limited to 300 MB—into one of the most performant file types on Propeller’s platform, which now supports IFC files up to 2 GB. This 6–7x increase in file size capacity came with dramatic performance gains. 

“For our customers with the most demanding projects, framerates are up anywhere from 20% to 170%, and memory usage has been drastically reduced, with our most demanding models seeing a 60x reduction in memory usage and similar reductions in data transfer," said Harry Morris, Propeller software engineer.

When streamed as 3D Tiles, IFC files retain all metadata: an inspector can click on an individual bolt in a bridge and see its size, manufacturer, the contractor responsible for installing it—whatever the users have uploaded. Courtesy Propeller.

Bringing Cesium’s Design Tiler into the platform took the Propeller team less than two months to roll out to full production deployment. When they released the new feature, the team also retroactively tiled all previously uploaded IFC files, delivering immediate value to their users without requiring re-uploads or workflow changes:

"Integrating the Cesium Design Tiler into our platform has revolutionized our support for BIM for all our customers. Cesium's expertise in the 3D Tiles open standard has delivered us a solution with greatly improved performance, accuracy, and feature richness—we've delivered highly requested features and given our construction customers confidence in an easy-to-use pipeline, revolutionizing their workflows," Morris said.

For Propeller’s users, streaming IFC files as 3D Tiles means a faster, higher quality experience. They can analyze large files, like viewing cross sections of this IFC model. Courtesy Propeller.

Explore how you can use 3D Tiles to make your datasets more accessible with Cesium’s 3D tiling pipelines.  

Propeller Streaming Complex IFC Files for Construction with 3D Tiles 

"The most brilliant engineering designs, no matter how well crafted, remain unrealized until their vision can be clearly communicated and understood by all stakeholders," said Wayne Sullivan, visualization lead at infrastructure engineering and consulting firm Parametrix. This philosophy drives Parametrix’s Advanced Visualization team: a group of software engineers and 3D artists using Cesium for Unreal, Cesium ion, and Google Photorealistic 3D Tiles to enhance public outreach and help win project bids by making complex designs easier to understand.

High-fidelity, photorealistic renderings of a proposed design helped the City of Las Vegas secure a $25 million grant for the Stewart Avenue Complete Streets project. Courtesy Parametrix.

Founded in Sumner, Washington, in 1969, Parametrix has expanded its services and geographic footprint across the United States. Today, the company provides multidisciplinary services in transportation, water resources, environmental planning, and community building, consistently ranking among top design firms in the regions they serve. In 2020, Parametrix acquired Civil FX, a startup that Sullivan helped build, specializing in interactive visualizations of transportation projects. 

Sullivan's Advanced Visualization team has become an integral part of Parametrix. The team's work supports projects across the company, dedicating 75% of their time to visualizing designs for community engagement and 25% to supporting grant and RFP proposals to win new business. Their workflow involves directly importing 3D models, created in applications such as Civil 3D, MicroStation, OpenBridge Modeler, or Revit, into Unreal Engine. The team uses Cesium for Unreal to precisely place these 3D models onto a WGS84 globe. With Cesium ion, they stream Photorealistic 3D Tiles into Unreal Engine to provide rich geospatial context and boost project realism, so stakeholders get a clear picture of changes coming to the communities they care about.

Built on open standards and APIs, Cesium for Unreal combines the 3D geospatial capability of Cesium with the high-fidelity rendering power of Unreal Engine, making smooth rendering and simulation available across industries. Photorealistic 3D Tiles are built on 3D Tiles, the Open Geospatial Consortium (OGC) community standard created by Cesium, to efficiently stream massive amounts of 3D data.  

Sullivan and his team began using Cesium in 2023 after learning about it on Reddit and LinkedIn. Today, Sullivan estimates that Cesium for Unreal and Photorealistic 3D Tiles cut about 30% of their team’s project time. “We use that extra time to build better experiences,” said Sullivan. 

Parametrix played a crucial role in helping the City of Las Vegas secure a $25 million federal grant to transform a 4.5-mile section of Stewart Avenue. This corridor is a vital route, with more than 35% of all users being pedestrians and cyclists. The City of Las Vegas identified that fragmented sidewalks and a critical lack of shade contribute to an unsafe and uninviting environment for pedestrians and other roadway users, as detailed in their Stewart Avenue Complete Streets Project Fact Sheet. 

“This is such an important project to the city and to the community in general,” Nicole Melton, the city engineering project manager, told KLAS news. “And when we do these public works projects that revitalize areas, we can spur economic development.” 

VR headsets were used to immerse the public in proposed designs during outreach efforts for the Stewart Avenue Complete Streets project. Courtesy Parametrix.

"Our visualization work was instrumental in communicating the project's vision to help secure its funding, and now we are excited to be involved with its implementation," explained Sullivan. The project is currently in its early design and planning phases, with construction anticipated to begin in 2027. Parametrix continues to leverage Cesium for Unreal and Photorealistic 3D Tiles in their work to gather public feedback. At a recent public meeting, Parametrix streamed the project concept to VR headsets, so attendees could immerse themselves in the proposed design.  

Parametrix’s visualization team extended Cesium’s open-source platform to showcase various aesthetic treatments for the Keystone Bridge project in Reno, Nevada. Courtesy Parametrix.

Parametrix: Keystone Bridge Material Switcher

Parametrix also used Cesium for Unreal and Photorealistic 3D Tiles on the Keystone Bridge project in Reno, Nevada, for the Regional Transportation Commission of Washoe. The project required showcasing aesthetic treatments for the bridge. Instead of creating static images to show treatment options, Parametrix developed a dynamic tool on top of Cesium for Unreal, leveraging its open-source foundation. This tool enables instant swapping of different colors of concrete as well as girder and rail colors and types, allowing project stakeholders to examine numerous aesthetic combinations. This interactive approach improves the efficiency of the stakeholder decision-making process, with the detailed model integrating with Photorealistic 3D Tiles for real-world context. 

“In the past, we’d have to render so many different aesthetic combinations on a project like this,” Sullivan said. “This tool saves us a lot of rendering time.” 

Parametrix’s Advanced Visualization team is committed to pushing the boundaries of project visualization. Their sights are set on leveraging Cesium ion for Gaussian splats production, a feature introduced at the 2025 Cesium Developer Conference. “Post-processing and cleaning up traditional photogrammetry can be time consuming,” explained 3D designer Justin Gould. “I’m looking forward to experimenting with Gaussian splats in Cesium to speed that up and using that data to inform custom geometries,” added Gould. 

Get started with a free Cesium ion account to pair your 3D models with accurate geospatial context. 

Parametrix Engages Communities and Wins Bids with Cesium

Editor's note: Cesium is committed to open source, open standards, and rapid innovation. We power training, planning, operations, and analysis across the US Department of Defense and Intelligence Community. We're proud to have collaborated with NUWC Division Newport and NSWC Carderock Division on this article about the impact of OTAs. Read the PDF here.

In March 2025, Defense Secretary Pete Hegseth issued the memo “Directing Modern Software Acquisition to Maximize Lethality,” mandating the use of the Software Acquisition Pathway for all Department of Defense (DOD) software development procurements. This memo also instructs DOD components to prioritize Other Transaction Authority agreements (OTAs) and Commercial Solutions Openings (CSOs) as the preferred methods for acquiring software capabilities. 

OTAs were created in 1958 to give DOD flexibility to incorporate business practices that reflect commercial industry standards and best practices into how it awards contracts. DOD historically employed OTAs in conducting research and development; in 2016, the National Defense Authorization Act expanded the use of OTAs to include prototype and production. This expansion provided the warfare centers with another alternative to a Federal Acquisition Regulation (FAR)-based procurement contract. 

NAVSEA’s warfare centers have been doing business this way for years. 

In 2016, the Undersea Technology Innovation Consortium (UTIC) was stood up as a non-profit research organization comprised of small and large technology companies, academia, and nonprofits who are developing undersea technologies and addressing defense and security challenges.  

By 2018, UTIC, represented by management firm Advanced Technology International, and NUWC Newport Division signed a three-year OTA contract (renewable for up to 10 years) to explore Undersea Technology Innovation in a broad range of undersea and maritime prototyping activities. NUWC Newport Division’s contracting professionals began exploring how to use OTA to deliver prototypes to the submarine Fleet faster and soon released its first Call for Topics under the OTA—the first warfare center to pursue this option.

Their success led to collaboration with other warfare centers including the Naval Surface Warfare Center (NSWC) Carderock Division via Dave Sracic, Distinguished Software Engineer for Fleet Signatures Systems.  

Sracic needed a solution that would let him approve software development without micromanaging it. In 2019, Sracic awarded two agreements utilizing NUWC Newport Division’s UTIC OTA, one of which went to Analytical Graphics Inc., whose subcontractor was Cesium.  

Cesium specializes in 3D geospatial technology, particularly for visualization and analysis. The company is considered a “non-traditional” government partner, which was a major aspect of the success of the collaboration. 

As part of the OTA prototype agreement, Cesium provided a platform for building 3D geospatial applications, including CesiumJS, an open-source library for 3D visualization in web browsers designed for robust interoperability and scaling for massive datasets. Cesium works to advance the geospatial ecosystem and open source, open standards, data sharing, and interoperability.  

In May 2024, NSWC Carderock awarded $2.2 million to Cesium through the OTA.  

Stills from Cesium’s bathymetry data set.

“UTIC had already proven to be effective for my team and our small initial toe-in-the-water approach had been highly successful. Given the choice between working with NUWC Newport to put together a new Request for Prototyping versus pursuing a traditional FAR-based path, it wasn’t much of a choice at all—I’ll take six weeks over 18 months any day,” said Sracic. 

Trent Tinker, director of Cesium’s federal business development, said, “From Cesium’s perspective, the OTA streamlined administrative processes and allowed for a direct line of communication with Navy customers. The OTA got us a step closer to the end users, and ensuring their data supports better, faster decisions is something that we’re really excited about.” 

According to Sracic, “Open source software is a building block of nearly every DOD system, and at some level, virtually all of the world’s most complex software systems. Our key challenge in building Navy combat systems is in using open-source software without finding ourselves trapped when it evolves faster than we do. Our thought was we’re using this open source CesiumJS and it does 80 percent of what we want, so let’s pay the experts who built it to make it do more.” 

As Sracic explained, “We got those changes back into CesiumJS, upstream, open source version, which means we do not have to keep a Navy fork of that software. The open source community maintains those specific changes. We care deeply about those features and use them heavily. Now that they’re part of the master branch, with test cases, we have reasonable confidence they won’t die, and we don’t pay some kind of sustainment fee. This is what the DOD policy aspires to—the government contributing back to open source.” 

“The OTA also enables Cesium to work with warfare centers on the open source position of their challenges,” said Tinker. “While some of the development stays with the government, other roadmap-aligned services go to the open source baseline and benefit everyone.” 

“Public-private partnerships between the Navy and UTIC members enable the Navy to create new paths to acquire and improve technological capabilities aboard its fleet, focusing on critical missions rather than the building blocks of visualization. Dave Sracic was proactive and flexible, and our terms were Firm Fixed Price, pairing our risk tolerance and desire to do meaningful work as a technology growth company,” said Patrick Cozzi, Cesium founder and Bentley Systems chief platform officer. 

“This is quantifiable value and return on investment, and sufficient to justify follow-on efforts to integrate capability into a combat system, which is a win for Navy in that it’s already risk-reduced and well understood,” explained Sracic. “And it’s a win for industry, which can do that work through non-competitive follow-on to the OTA.”

When it comes to infrastructure investments, visualization transforms public engagement from abstract discussions to concrete decision-making. HNTB’s Immersive Media Solutions team uses Cesium ion, Cesium for Unreal, Cesium for Unity, and Google Photorealistic 3D Tiles to help community stakeholders better understand proposed infrastructure projects and engage meaningfully in the approval process. 

A flythrough of a proposed design to replace the Bourne Bridge was used in public outreach efforts as part of the Cape Cod Bridges Program. Courtesy HNTB. 

HNTB: Bourne Bridge

Founded in Kansas City, Missouri, in 1914, HNTB initially focused on designing railroad bridges. Today, the company offers comprehensive services in engineering, architecture, planning, and construction management, primarily focusing on transportation infrastructure. Their architectural services extend to designing and managing projects for public assembly facilities, including numerous prominent sports stadiums and arenas.  

“When presenting an infrastructure project proposal for public engagement, it’s crucial that local stakeholders and property owners understand where their property, building, or favorite park is located in relation to the proposal, and that the surrounding context is recognizable,” HNTB immersive media solutions manager Dave Willard said. 

Willard and his team create real-time interactive media to visualize and assess infrastructure project designs, from single highway interchanges to 30-mile road and rail corridors. They load a diverse range of 3D engineering and design models of roads, bridges, or rail networks—created in applications like OpenRoads, Revit, MicroStation, Civil3D, or SketchUp—directly into Unreal Engine or Unity. The team uses the Cesium for Unreal or Cesium for Unity plugins, depending on the project, and accesses Photorealistic 3D Tiles via Cesium ion to add real-world context, enriching project visualizations for public review and community engagement initiatives.  

Designed to deliver highly detailed and realistic data for immersive environments, Google Maps Platform's Photorealistic 3D Tiles enable immersive experiences that scale from individual buildings to entire cities. Photorealistic 3D Tiles leverage the Open Geospatial Consortium (OGC) community standard 3D Tiles format, created by Cesium, which performantly streams massive amounts of 3D geospatial data. 