Cesium for Omniverse v0.29.0

Cesium for Unity Samples v1.25.0

CesiumJS 1.144

Architecture, Engineering, and Construction (AEC)

As Cesium and Bentley Systems have come together to build the comprehensive open platform for the built and natural environment, we’re pairing Bentley’s deep AEC experience with interoperability to serve the community. To bring CAD-style visualization concepts to CesiumJS, our team has built a set of AEC workflow extensions to glTF, the open standard foundational to the new 3D Tiles 2.0. 

CAD users expect specific—yet common and well-established—visualization requirements, including crisp hard edges and silhouettes, lines drawn with precise widths and dash patterns, points sized to convey semantics, textures that hold a consistent on-screen scale at any zoom, and planar fills with well-defined depth and masking behavior. These are standard features in tools like Bentley’s MicroStation and other engineering design environments, and now they are coming to CesiumJS and Cesium for Unreal. Many have already shipped and others are landing soon. 

Infrastructure engineers often want non-photorealistic visualizations of their designs. In CAD-oriented workflows, visualization of the edges of a surface can be as important as visualization of the surface itself. CesiumJS now supports loading and rendering CAD-style edges. 

To accomplish this, we devised new glTF specifications EXT_mesh_primitive_restart and EXT_mesh_primitive_edge_visibility which extend the 3D Tiles format such that edge geometry can be properly embedded inside design model tilesets. 

Powered by these extensions, CesiumJS can now render surfaces with edges superimposed alongside the surfaces and just the edges (no surfaces). 

Experiment with edge display in this Sandcastle. 

Visible edges rendering in CesiumJS alongside surfaces.

A CAD model rendered in CesiumJS with visible edges drawn without any surfaces (wireframe style).

The edge visibility extension encodes one edge type per triangle edge: 

silhouette is drawn only when one adjacent triangle faces the camera and the other faces away. 

hard is always drawn and represents a real sharp edge or boundary. 

repeated hard marks shared hard edges without duplicating them. 

Edge classifications encoded by the extension: hidden edges are never drawn, hard edges are always drawn, and silhouette edges are drawn only when one adjacent triangle faces the camera and the other faces away.

The edge visibility extension also supports edge-level materials and connected edge strings: 

materials defines edge materials separate from triangle surfaces or primitives, so edge appearance can be controlled independently. 

lineStrings defines connected edge segments using primitive restart (EXT_mesh_primitive_restart) for continuous outlines or edges needing different materials. 

CesiumJS introduces a dedicated edge rendering pass that decodes this visibility data, reconstructs the edges as quad-based geometry (to guarantee stable screen space widths across browsers and GPUs), and integrates them with the main surface pass using feature ID and depth comparisons to avoid z-fighting. 

For more information, check out these PRs: 

Add support for GLTF extension: EXT_mesh_primitive_edge_visibility. 

Add EdgeDisplayMode enum for controlling edge rendering. 

CAD workflows often rely on line and point appearance to convey semantics. Line thickness and dash patterns are commonly used to differentiate boundaries, annotations, or feature classes. Point color and size can be used to highlight survey markers, control points, or other features. To accomplish this, we introduced new glTF extensions BENTLEY_materials_line_style and BENTLEY_materials_point_style, which extend the 3D Tiles format such that glTF-embedded lines and points can be styled for design model tilesets, both of which are now supported in CesiumJS. 

CesiumJS rendering edges with width and dash pattern and colorized points with a variety of diameters.

Line styling naturally works well with EXT_mesh_primitive_edge_visibility. Edge visibility determines which edges are drawn, while line styling determines how those edges appear. Used together, edges can achieve unique styling. 

The line styling extension adds two properties to a glTF material, which apply to any line primitive or visible edge that references the material: 

width defines the thickness of the line in screen pixels, ensuring visual consistency regardless of camera distance or world scale. 

pattern defines a repeating on/off dash pattern encoded as a 16-bit unsigned integer, where each bit corresponds to one screen pixel along the line. This is compact, GPU friendly, and expressive enough to cover common CAD line styles, such as solid, dashed, and dotted lines. 

In the case of points, a single styling property is specified (color can be inferred from the material itself): 

diameter is the diameter of each point in CSS pixels. 

Constant level of detail (LOD) textures 

In many engineering and geospatial workflows, textures are used to convey representative surface detail. This can include patterns on terrain, hatching on facades, or material finishes on infrastructure. With standard UV-based texture mapping, however, those patterns don’t remain consistent across different viewing scales. Textures visually shrink as the camera zooms out and grow as it zooms in, making fine detail disappear at distance and appear unnaturally coarse up close. 

We have introduced the glTF extension EXT_textureInfo_constant_lod to support texture consistency. Using this extension, CesiumJS provides a constant LOD texture coordinate generation technique. Rather than relying on baked-in UVs, texture coordinates are computed dynamically each frame to maintain a roughly constant texel-to-pixel ratio on screen as the camera moves. Adjacent scale levels are smoothly blended so transitions between LODs do not appear sudden. 

With EXT_textureInfo_constant_lod support in CesiumJS, the texture maintains a roughly constant on-screen scale as the camera zooms, with adjacent LOD levels smoothly blended.

For the effect to look correct, glTF files need to be authored with the extension in mind. Textures should be designed to tile seamlessly, since they will repeat across surfaces at varying scales. The values baked into the extension must be chosen to match the real-world scale of the model and the expected viewing distances. This includes how often the texture repeats per meter, its offset, and the distance over which the LOD blending applies. 

Planar polygons with filled interiors are fundamental elements in many CAD workflows, where the appearance of a polygon’s interior fill can convey meaning beyond just a flat color. A filled region may need to mask out geometry behind it, sit behind a coplanar hatch pattern or text annotation, or be toggled on and off in a wireframe view. For example, a designer may superimpose some lettering as a label on a wall, expecting that the label always appears on top of the wall and be readable without any interference from the underlying wall geometry. The team created the BENTLEY_materials_planar_fill extension to support these sorts of behaviors as material-level properties within glTF. 

With BENTLEY_materials_planar_fill support in CesiumJS, the textured text (non-lines) and planar polygons exhibit no Z-fighting even though they are coplanar with the red surface (first image).

The extension is applied to a glTF material and signals two things to CesiumJS. First, it indicates that any primitive using the material is planar, so the engine can apply appropriate depth sorting. This ensures associated edges are in front of fills and planar primitives are in front of overlapping nonplanar ones. Second, it exposes a small set of properties that customize how the fill is drawn: 

wireframeFill controls if the fill is shown in a wireframe view (never, always, or only when the user has toggled fill display on). 

backgroundFill causes the fill to be drawn using the view’s background color, which is useful for creating an “invisible” polygon that masks out geometry behind it. 

behind causes the fill to be drawn behind other coplanar geometry that belongs to the same logical object, mitigating z-fighting in cases like hatch patterns over a filled polygon, text inside a filled rectangle, or line work overlaying a solid surface. 

Together, these properties give CAD applications a compact, material-driven way to describe the desired fill behaviors in CesiumJS. 

Support for BENTLEY_materials_planar_fill is upcoming in CesiumJS. 

By bringing these AEC extensions to glTF as part of 3D Tiles 2.0 and into CesiumJS, Cesium and Bentley want to empower the community with open, interoperable, best-in-class technology, benefiting the entire 3D geospatial ecosystem.   

Your input and use cases are what guide our work. Try the Sandcastle and share your feedback on the forum.  

Introducing CAD-Style Workflow Extensions for glTF and 3D Tiles 2.0 

At the 2026 Cesium Developer Conference, Cesium announced a Technology Preview introducing two key advancements: broader, streamlined support for BIM/CAD formats in Cesium ion and new API endpoints for querying model metadata. These improvements make it easier to access and use design models in digital twins, reducing the required time, effort, and specialized expertise required.

The completed element inspection app built using the Cesium ion Asset Elements API tutorial.  This screenshot shows a BIM/CAD building model with the CesiumJS view filtered and styled to display the results of a query for doors and windows. 3D model provided by Autodesk and tiled from the Revit source with Cesium ion.

We’ve added a new Cesium ion tiler for the most common BIM/CAD formats:

This tiler and the API endpoints described below are powered by proven Bentley software including iTwin Platform and iModels, now exposed through Cesium ion’s API and user interface.

While Cesium ion’s existing support for tiling IFC and RVT is still in place, the new BIM/CAD tiler offers more convenience—no plugin required for all source file types. It also maintains more model metadata in a backend database that powers our new API endpoints. This unlocks file-based workflows to import design data created with the tools you already use every day. 

We’ve also made it easier to properly locate your model in the real world by choosing the right Coordinate Reference System (CRS) when you upload your model—the first of many planned improvements to eliminate the friction that challenges BIM/CAD workflows.

The Coordinate Reference System (CRS) selector makes it easier to correctly locate your BIM/CAD models when uploading them to Cesium ion.

crs-selector

Many users already share BIM/CAD models with stakeholders using Cesium ion. Our Early Access participants tell us that these changes make it easier and faster: simply upload and tile the source in Cesium ion, add it to a no-code Cesium Story to put it in geospatial context, and share a link with stakeholders. 

Developers of custom applications can leverage Cesium ion’s API as a pipeline to bring BIM/CAD models to their solutions in the open 3D Tiles format, whether they are building with a Cesium client like CesiumJS or Cesium for Unreal, or with other open-source or commercial choices. 

Leverage the richness of BIM/CAD models with new APIs

Design models aren’t just geometry; they’re hierarchical, interconnected, metadata-rich datasets. Models uploaded to Cesium ion frequently embed hundreds or even thousands of per-element properties. Models can contain millions of elements, each with hundreds of properties, resulting in the tileset metadata becoming larger than the geometry when streamed. Embedding all properties would negatively impact streaming performance—with most properties never being used downstream.

To avoid wasted runtime memory usage, Cesium ion takes a different approach. The BIM/CAD tiler creates an optimized 3D tileset containing the geometry with key element properties and enables the full element properties to be searched and queried with the new Cesium ion Asset Elements API. The API provides straightforward methods to request metadata about a model’s elements by type. For example, in the building model application shown above, the developer queried for information about the model elements with types window and door.

As we expand metadata support with the new BIM/CAD Tiler, we’re actively seeking feedback from early adopters on whether they also need options to embed custom, user-selected metadata or export it for use in applications that can’t access ion’s API. 

Using Cesium ion’s REST API, developers can access the metadata properties for elements in a 3D model, returned as JSON as shown here for visualization and interactions.  See the Cesium BIM/CAD Data Guide to learn more.

With CesiumJS and other runtime engines, developers can use the API to build applications for model stakeholders, engineering teams, and other infrastructure professionals to visualize and interact with model metadata in high-precision, element-specific workflows.

The Utah Department of Transportation (UDOT) is a leader in digital delivery workflows for massive, multi-phase projects like this overpass. The 3D model provided as Bentley OpenRoads Designer (DGN) files and tiled with Cesium ion. Data courtesy of UDOT.

For example, U.S. state Departments of Transportation are creating purpose-built digital delivery applications like a Project Corridor Viewer, transforming transportation projects into immersive, interactive 3D experiences. These viewers bring engineering data into a Cesium-enabled geospatial context and empower teams to query and search to visualize and analyze the information they need throughout the entire infrastructure lifecycle, from planning and design to construction and operations.

"UDOT has been the pioneer for digital delivery for the DOTs. Now the question isn’t what’s possible...it’s what’s next? As we continue to push beyond models into connected data and digital twins, we’re looking for the next breakthrough that moves our industry forward."

— Nicole Williams, Vice President Kimley-Horn

At the 2026 Cesium Developer Conference, Nicole Williams of Kimley-Horn explained how she wrote the playbook for state DOT digital delivery—from the first 3D model used as a legal construction document to more than 15 paperless projects. She demonstrated that the design-to-operations data gap is a pipeline problem solved by bringing geospatial and engineering together on one platform.

What’s coming next: build richer applications, more easily

We can’t wait to see what users build with these features, but we’re just as excited about what’s coming next.

Throughout this summer and fall, look for:

Ongoing improvements to the tiling pipeline speed and quality for BIM/CAD models. 

The ability to update BIM/CAD models in Cesium ion while maintaining access to past versions.

Change detection APIs to query for the differences between model versions. Visualize what changed over time to power workflows for revision review, optioneering, and communicating changes across distributed teams.

More georeferencing improvements to accurately locate models in the real-world faster, more intuitively, and with fewer extra steps.

Clipping tools in Cesium ion (server-side) and in CesiumJS and Cesium for Unreal (client-side). We are working to eliminate the painstaking steps often required to capture precise model footprints that enable clean visualization of a model placed in real world context.

Precise mouse snapping to model geometry to enable more accurate interactivity, such as picking elements, selection, calculations and visualization of points of measurements on design models streamed from Cesium ion. These enhancements are essential to the design review that is part of digital delivery workflows.

API-enabled filtering for easier and tighter control of what data is displayed in your applications.

After attending the 2026 Cesium Developer Conference keynote on Cesium’s new BIM/CAD capabilities, Dakota Mohan, Digital Delivery Lead at infrastructure design and engineering firm JMT, rapidly built a prototype of design models from Bentley Digital Cities Infrastructure Cloud streamed into CesiumJS. The app enables interactive exploration of a roadway corridor and IFC bridge model with advanced visibility controls, element queries, and attribute-based filtering of construction details like rebar. Dakota presented his work on the very next day at the conference! Video courtesy of Dakota Mohan and JMT. Read more on LinkedIn.

dakota-mohan-jmt-devcon26

We’re grateful for the feedback we’ve already received from Early Access users of the BIM/CAD tiler and our new API endpoints. We’d love to hear from you too; let us know what works for you (or what doesn’t!). Which of the coming features are most important to you? What will you build as we continue to lower the barrier to entry?

Join the conversation on the Cesium Community and help shape the future of BIM/CAD workflows on the open 3D geospatial platform.

At the 2026 Cesium Developer Conference, Dakota Mohan of JMT discusses his rapid experimentation with Cesium’s new BIM/CAD support with Shehzan Mohammed, Head of Product Management for Platform at Cesium, a Bentley company.

Unlock Design Intelligence: Expanded BIM/CAD Support and Metadata Queries in Cesium

For industries managing vast linear infrastructure like railways and power lines, safety and reliability are paramount—and ensuring that safety requires constant monitoring and analysis of immense volumes of data. The Cross Product, a software development company specializing in LiDAR data processing, addressed this challenge by creating TCP Studio, a 3D visualization platform built with Cesium.

TCP Studio V9

From raw data to a custom visualization platform

The Cross Product recognized a critical gap in their users’ workflows: while TCP could process massive point clouds to extract meaningful information, users often lacked the specialized tools to visualize and interact with these rich datasets. This was a barrier to turning processed data into timely, actionable insights for infrastructure management.

To bridge this gap, The Cross Product developed TCP Studio, a SaaS solution built from the ground up using CesiumJS. The Cross Product also converts LAS point clouds into 3D Tiles via Cesium ion’s tiling pipeline. “Previously, we assumed clients had their own visualization tools, which was only partially true,” explained Elise Vi Nhu Ba, R&D engineer at The Cross Product. “A dedicated interface is now a significant advantage, allowing us to showcase our solutions’ capabilities through a custom-built environment with full control over the UX.”

This control is crucial. TCP Studio provides an intuitive web-based interface where clients can explore their infrastructure in a high-fidelity 3D environment, interact with processed data, identify issues, and make informed decisions—all without needing to install or maintain their own complex software.

As part of the Bentley Activate program, a startup accelerator designed to support companies building innovative solutions on digital twin platforms, The Cross Product was able to maximize the work of a small team and accelerate their work with the Cesium platform.

The TCP Studio Project Explorer provides a high-level overview of infrastructure assets, overlaid on Sentinel-2 imagery via Cesium ion. Courtesy The Cross Product. 

Speed and automation: accelerating time to value

One of the most significant advantages The Cross Product gained from building with Cesium was development speed. Following an agile approach, the team delivered the first demonstration version of TCP Studio in just three months. This rapid prototyping validated their approach and enabled them to present a working solution to their users early in the development cycle.

This speed translates directly to client value. By using Cesium ion to tile massive LAS point clouds into 3D Tiles streamed to CesiumJS, TCP Studio delivers reliable performance, even with complex scenes. The platform also features solutions for automated measurements and issue detection. For example, users can automatically detect and flag areas where the track gauge on a railway is outside of the specified tolerance. This automation saves significant time and allows engineers to focus on critical maintenance tasks.

The Cross Product points to Cesium for a 10% growth in revenue in Q1 2026 by enabling new deals and creating a recurrent revenue stream through subscriptions.

TCP Studio features automatic detection of potential issues in large infrastructure projects. Courtesy The Cross Product.

A scalable foundation for high-performance geospatial visualization and analysis

The ability to quickly build and deliver a high-performance, scalable 3D visualization and analysis solution for massive geospatial datasets was crucial for The Cross Product.

Leveraging CesiumJS for visualization and Cesium ion for data tiling and hosting, The Cross Product was able to focus on its core expertise: developing advanced LiDAR processing algorithms and creating a tailored user experience.

“Cesium enabled us to transform massive LiDAR datasets into actionable insights and empower clients to remotely manage and explore their infrastructure within a high-performance, large-scale 3D platform.”

Elise Vi Nhu Ba, R&D Engineer, The Cross Product

Users can dive into detailed 3D views of their infrastructure, create and manage issues, and analyze measurements within TCP Studio. Courtesy The Cross Product.

For large infrastructure projects, CesiumJS provides a foundation for scalable and customizable solutions for end users. For more information about this project, contact Andrés Serna, CEO, The Cross Product. Explore how open source CesiumJS can help bring 3D visualizations in browser to your users. 

The Cross Product Transforms Raw LiDAR Data into Actionable Infrastructure Insights with Cesium

The most costly risk to major infrastructure projects isn't bad weather or poor funding: it's the risk that slips past the constructability review. If not caught soon enough, a single contradiction—like major utility conflicts or an unworkable traffic management plan—triggers millions in wasted taxpayer funds and guarantees years of delay.  

A critical conflict revealed during constructability review: a proposed highway support column lands directly on existing railway tracks. Courtesy WSB.

Although the constructability review is the critical gatekeeper, the process is often trapped in 2D static documents. Engineering design and consulting firm WSB is using Cesium-powered geospatial capabilities in Bentley Infrastructure Cloud Connect to ensure design flaws are caught early.  

Connect provides a secure, open, and scalable environment for engineering services firms, construction firms, and owner-operators to store, manage, and share infrastructure files and data. Cesium’s integration with Connect offers a unified web experience to visualize infrastructure data in full geospatial context.  

“Civil engineering isn’t just about technical analysis—it’s also about solving geospatial challenges,” said Andy Kaiyala, vice president of digital construction management at WSB. An early adopter of Connect, Kaiyala adds “Cesium’s capabilities allow us to incorporate critical spatial information early in the process, helping us make smarter decisions about fitting infrastructure into available space while minimizing disruption.” 

Demonstration showing Cesium’s integration with Bentley Infrastructure Cloud Connect.

Demonstration showing Cesium’s integration with Bentley Infrastructure Cloud Connect.

Cesium + Bentley Infrastructure Cloud Connect

CesiumJS serves as Connect’s visualization front end, rendering massive infrastructure datasets on an interactive map that scales from a global portfolio view—covering multiple projects across regions—down to detailed, project-level insights. Engineering-grade data (such as BIM models, point clouds, and reality meshes) is efficiently streamed as 3D Tiles, the Open Geospatial Consortium (OGC) community standard created by Cesium.  Connect also integrates Google Photorealistic 3D Tiles, leveraging the 3D Tiles standard to provide high-resolution 3D representations of major cities and terrain. 

Apart from catching obvious errors, Cesium’s geospatial capabilities in Connect help teams uncover hidden, high-impact risks that traditional reviews miss. On a project in the southern United States, WSB quickly identified and effectively communicated a high-risk design problem:  a proposed railroad bridge and major sewer infrastructure were planned adjacent to a protected historic building, prompting a redesign before the project moved to final design —and potentially saving months in schedule delay and millions in public funds. 

Cesium-powered geospatial capabilities in Connect reveal design conflict between a proposed railroad bridge and a historic building. Courtesy WSB. 

A bottom-up view highlights further design conflict between sewer pipes and the proposed bridge pilings. Courtesy WSB.

“Cesium provides a high-performance, scalable, and geospatially accurate environment that brings full context to infrastructure project designs in Connect,” said Bill McNamara, senior director of iTwin and portal experience at Bentley. “It’s not just empowering our end users. It’s driving value across the ecosystem of infrastructure stakeholders.” 

While testing the Cesium integration with Connect, WSB shared curated views of 72 projects with over 900 external stakeholders representing 86 organizations, including state departments of transportation, rail authorities, utilities, and public agencies. “We can bring more stakeholders to the review process earlier, thanks to the intuitive way Cesium enables us to visualize project designs. It’s become a key differentiator for us,” Kaiyala explained.     

“When we show a design model with a 2D map, stakeholders nod politely,” added WSB director of digital construction management strategy Corey Johnson. “But when we show it on an interactive Cesium-powered map surrounded by Photorealistic 3D Tiles, their eyes light up. They immediately understand the proposed design and any constructability issues.” 

For WSB, visualizing engineering data in true geospatial context has elevated constructability reviews from a static checkpoint to a dynamic driver of smarter, faster, and more transparent project delivery. As more organizations adopt Cesium-powered capabilities in Connect, early detection and clear communication of design risks resolve conflicts before shovels hit the dirt. Kaiyala summed up the approach: “Ultimately, Cesium isn’t about pretty pictures; it’s about putting valuable information in the hands of the people who build the infrastructure we all rely on.”  

Sign up for a free Cesium ion account to pair your 3D models with accurate geospatial context.  

WSB Transforms Constructability Reviews with Cesium and 3D Tiles in Bentley Infrastructure Cloud Connect

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

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. 

Prior to adopting Cesium, providing accurate geospatial context for major projects was a significant time investment, requiring the team to manually model, texture, and detail existing buildings.   

“Now, we bring that data in from Cesium and use it as-is in many cases,” Willard explained. “It removes the headache on our end, allowing us to focus our time on visualizing the proposed project instead of the buildings that are already there.”   

HNTB's visualization team extended Cesium's open-source platform to vertically align long linear infrastructure models with the Earth's curvature. Courtesy HNTB.

This capability proved invaluable to HNTB during its work on a long highway corridor project in the southeastern United States. 

“Manually modeling existing buildings for contextual detail on long linear projects historically required over 1,000 hours of work,” Willard said. “Cesium reduces that time to between 200 and 300 hours." 

The extensibility and open-source foundation of Cesium enabled HNTB's visualization team to build a tool that addressed the challenge they faced in accurately aligning this 26-mile corridor model. Traditional engineering designs don't account for the Earth's curvature, leading to noticeable vertical discrepancies over long distances—in this case, the model floated about 80 feet above the earth at one end and dipped 80 below the other. 

HNTB developed a non-destructive mesh blending tool on top of Cesium that could automatically apply the necessary curvature to large, complex 3D models. This allowed them to continuously update design models in their Unity environment, with the tool automatically correcting for Earth's curvature, ensuring "ground truth accuracy" for their clients.  

“One of the really cool things about having Cesium is the ability to build other tools on top of it,” remarked Adam Liss, HNTB senior immersive media specialist. 

Willard's team, serving as a key consultant for the Massachusetts Department of Transportation on the Cape Cod Bridges Program, was tasked with presenting 10 different interchange configurations for public review. 

Traditionally, this would have necessitated creating numerous individual videos and renderings for each combination, making it difficult for the public to compare scenarios and provide feedback. Instead, Willard's team applied their Cesium-powered interactive media capabilities, so presenters were able to dynamically display and toggle between these different interchange options, with detailed surroundings the reviewers expected to see, in real time via pixel streams and locally-run applications during public meetings. 

HNTB’s team also built masking tools using Cesium. These tools enable them to overlay potential designs directly onto existing structures, making it easy for viewers to compare the past with the proposed future.

For a bridge proposal to link barrier islands along the Gulf Coast of Texas, HNTB integrated Cesium’s World Bathymetry data into their visualization. This addition helped stakeholders understand how underwater topography and the locations of historic shipwrecks impacted the busy shipping lanes beneath the proposed bridge design. “It’s important to be able to render this 2D-type information in a 3D context,” Liss explained. 

This streamlined process, powered by Cesium, enables quick visualization of design alternatives and facilitates efficient collection of public input to identify preferred designs for their projects. 

Innovation defines HNTB's 111-year legacy in infrastructure, a commitment clearly seen in their Immersive Media Solutions team's work to transform public engagement by making the abstract concrete. When it comes to Cesium, the team feels like they are just scratching the surface. “As we transition away from manual modeling of existing context, technologies like Cesium will continue to make our workflows much faster,” Willard said. 

Looking into the future, Willard’s sights are set on digital twin delivery, bridging the work between owner-operators and engineering firms.  

“The end goal isn't just about interactive real-time visualizations; it's transforming those visualizations into informational environments—digital twins,” Willard said. “Imagine delivering a complete football stadium or road corridor, complete with all its element-level metadata as a digital twin. That, to me, is a truly valuable deliverable for an engineering firm.” 

Bring accurate real-world context, like Photorealistic 3D Tiles, to your infrastructure projects with Cesium ion. 

HNTB Streamlines Infrastructure Project Visualization with Cesium 

When we issued the call for proposals for this first Cesium Developer Conference, we were curious how many talks we would receive and what themes would stand out. Cesium has a history in aerospace and now serves a thriving community of open source geospatial users across many different industries, including architecture, engineering, and construction (AEC).

We were happy to see submissions from longtime advocates of CesiumJS, 3D Tiles, and other complementary technologies and topics from the open community—and some surprises. In fact, we received so many abstracts that we expanded the total number of presentations from approximately 50 to 90! There will be a ton for attendees to explore at the event.

Register for the Cesium Developer Conference

The biggest concentration of talks came from AEC and digital twin implementations. We were able to accept 21 full sessions and five lightning talks for the conference from submitted AEC/digital twins abstracts. The sessions are split into three groups, two of which will have to run concurrently, because of the volume. It’s a great “problem” to have.

The topics for this category range from aggregating multiple project sites in a single geospatial experience to providing XR experiences for inspecting and exploring asset conditions in the context of a dynamically updated digital representation of a system. Some presenters will focus on using the rich information in building information modeling (BIM) data in geospatial context, while others will focus on using a 3D map as a communication vehicle.

There will be digital twin projects presented that focus on rail, roadways, buildings, campuses, and whole cities. We anticipate these presentations will drive conversations at the conference networking events about how to bring open geospatial concepts into even more corners of the AEC industry.

A few of the organizations who will present in the AEC and Digital Twins track: 

Arcadis will share how they are using Cesium for Unreal Engine for architectural visualization. 

Holosim will present an exciting story about using immersive gaming technologies and 3D Tiles to plan theme parks.

Pennoni will demonstrate how their team uses 3D Tiles and Cesium with game engine technologies to visualize future plans. 

EARTHBRAIN will demonstrate how they are digitalizing the construction process, especially around earth moving workflows. 

Mott MacDonald will discuss how they use Cesium for a web-based GIS for AEC. 

CalTa will demonstrate how they create digital twins from reality capture information to help customers manage real-world assets. 

Project Controls Cubed will present on how they are using iTwin and Cesium to modernize water treatment systems.