A century-old building deserves more than a collection of photographs or a set of 2D drawings. For historic districts such as Yanqingli, buildings are densely distributed along narrow streets, interconnected courtyards, and complex indoor-outdoor spaces. At the same time, the site remains part of an active urban environment, with residents and visitors moving through the area.

This creates a practical challenge:

How can historic buildings be documented quickly and comprehensively while minimizing disruption to the site?

For the Yanqingli Historic District digital documentation project, Tianbaonet developed an integrated workflow centered on the L2Pro handheld SLAM scanner, combining 3D scanning, point cloud processing, 3D Gaussian Splatting, and 3D visualization.

The solution reduced the acquisition time for a single building to approximately 1–2 hours, generating high-density true-color point clouds and photorealistic 3D Gaussian Splatting models. The resulting digital assets were then integrated into a 3D visualization platform, extending the value of the survey beyond data collection to measurement, visualization, digital archiving, and long-term reuse.

01. The Challenge: Digitizing a Complex Historic District

Digitizing a historic district involves much more than surveying individual buildings. Buildings, streets, courtyards, and interior spaces form a continuous and highly complex environment.

At Yanqingli, narrow streets and densely arranged buildings made conventional surveying workflows difficult to organize. The survey also had to account for residents and visitors using the site during the project.

The team needed to capture architectural elements such as walls, doors, windows, beams, columns, and decorative details while minimizing interference with normal site activities.

• Traditional surveying methods typically require a combination of measuring tapes, total stations, close-range photography, and other equipment. Depending on the building, fieldwork may take 1–3 days per building.
• Station-based equipment can also require frequent repositioning when working in narrow streets or across interconnected indoor and outdoor spaces, increasing operational complexity.
• UAV photogrammetry provides valuable aerial perspectives, but its effectiveness can be limited by vegetation, building interiors, narrow streets, and other areas with restricted visibility.

The challenge, therefore, was not simply to achieve higher measurement accuracy. The project required a workflow that could capture complex spaces faster, record them more completely, and preserve the data for downstream digital applications.

Based on years of experience in historic building surveying and digital preservation, Tianbaonet developed a non-contact, efficient, and reusable digital documentation workflow centered on the L2Pro handheld 3D laser scanner.

02. The Solution: From Field Capture to Digital Application

The solution is not a single device, but an integrated digital production workflow:

L2Pro Handheld SLAM Scanning → Point Cloud Processing → 3D Gaussian Splatting → 3D Visualization

1. Rapid field data acquisition

During fieldwork, surveyors carried the L2Pro through the interior and surrounding areas of the buildings, capturing spatial data while moving.

By integrating LiDAR, visual imagery, IMU-based inertial positioning, and RTK positioning, the system can map complex environments while simultaneously collecting spatial and color information.

The workflow is particularly suited to narrow streets, enclosed spaces, low-light environments, and other areas where conventional surveying can be difficult to deploy.

The resulting data includes georeferenced, high-density true-color point clouds, providing a detailed digital representation of the surveyed environment.

Because the system is handheld and non-contact, it eliminates the need for extensive equipment setup and helps minimize physical interference with historic structures.

2. Automated point cloud processing

After field acquisition, the collected data can be processed in LixelStudio, where noise filtering and point cloud reconstruction are completed efficiently.

The processed point cloud then serves as the geometric foundation for subsequent 3D reconstruction.

3. 3D Gaussian Splatting reconstruction

The point cloud and imagery are further processed using Lixel CyberColor to generate high-fidelity LCC 3D Gaussian Splatting models.

The point cloud provides geometric constraints, while the captured imagery contributes rich visual information, producing a photorealistic digital representation of the historic environment.

4. 3D visualization and application

The resulting digital assets are ultimately published through Headsolution, Tianbaonet's 3D visualization and micro-application platform.

This creates a continuous workflow from:

Field Capture → Data Processing → 3D Reconstruction → Visualization → Application

Instead of combining disconnected tools and services from multiple vendors, the project establishes an integrated workflow for historic-building digitization.

03. One Survey, Multiple Digital Deliverables

The value of the project does not end with field data acquisition.

The same field dataset generated two core digital deliverables:

High-density true-color point clouds + 3D Gaussian Splatting models

Rather than duplicating the same function, the two datasets serve different purposes.

01. High-Density True-Color Point Clouds

Making Historic Buildings Measurable and Analyzable

The point cloud data is georeferenced and provides centimeter-level geometric detail, allowing users to extract plans, elevations, sections, and detailed architectural measurements directly from the digital dataset.

Arbitrary sections can be generated as required, allowing architects, conservation teams, researchers, and surveyors to access the information they need without repeatedly returning to the physical site.

The point cloud therefore serves as the geometric data foundation for subsequent surveying, documentation, analysis, and restoration work.

02. 3D Gaussian Splatting Models

Making Historic Buildings Immersive and Accessible

The 3D Gaussian Splatting model provides a highly realistic representation of the historic environment.

Details such as brick walls, masonry textures, doors and windows, decorative elements, and architectural features can be viewed in an immersive 3D environment.

The model supports applications such as real-time navigation, sectioning, measurement, and annotation, transforming a traditional architectural record into an interactive digital space.

Instead of simply documenting dimensions, the digital model allows users to virtually enter, explore, present, and share the historic environment.

04. From Digital Documentation to Long-Term Reuse

For historic-building digitization, completing a scan is only the beginning.

The real value lies in whether the resulting data can continue to support different applications after the initial survey has been completed.

For Yanqingli, Tianbaonet integrated the collected, processed, and reconstructed digital assets into the Headsolution 3D visualization and micro-application platform.

A single field survey can therefore support multiple use cases:

Surveying and Restoration Design

Point cloud data can be used directly for measurement, drawing production, and subsequent restoration and design workflows.

Digital Archiving

The complete spatial information of century-old buildings can be preserved digitally for long-term storage and future reference.

Remote Collaboration and Project Presentation

Project stakeholders can remotely explore the historic district in 3D without being physically present, making the digital model a practical tool for communication and project presentations.

Cultural Heritage Communication

Photorealistic 3D scenes can be used for online exhibitions and digital cultural heritage experiences, helping historic districts reach a wider audience.

Digital Twin Foundation

For future district-scale digital twin development, existing point cloud and 3D Gaussian Splatting datasets can serve as the spatial foundation, reducing the need for repeated field acquisition.

The workflow therefore transforms a one-time survey into a reusable digital asset.

05. Improving Efficiency, Completeness, and Digital Reusability

Compared with conventional surveying workflows, the technology system implemented at Yanqingli provides a more integrated approach to historic-building documentation.

• Field Efficiency:A single building can be captured in approximately 1–2 hours, significantly reducing the time required for on-site data acquisition.
• Spatial Completeness:The handheld SLAM workflow supports continuous capture across indoor and outdoor environments, helping document interconnected spaces that can be difficult to survey using conventional station-based methods.
• Non-Contact Documentation:The scanning process minimizes physical interaction with historic structures and reduces the need for extensive equipment setup.
• Dual Digital Deliverables:The same field dataset can generate both accurate point clouds for measurement and photorealistic 3D Gaussian Splatting models for visualization.
• Long-Term Data Value:By integrating the results into a 3D visualization platform, survey data can continue to support conservation, research, presentation, collaboration, and future digital-twin development.

From Survey Data to a Sustainable Digital Asset

The Yanqingli project demonstrates that the value of handheld SLAM scanning is not limited to faster field acquisition.

The project establishes a complete digital workflow in which one field survey provides the foundation for surveying, documentation, visualization, and future applications.

The combination of point clouds and 3D Gaussian Splatting also gives different types of digital data a clear role: point clouds provide the geometric foundation for accurate measurement, while 3D Gaussian Splatting provides a photorealistic environment for visualization and immersive exploration.

Most importantly, integrating these deliverables into a 3D visualization platform allows the data to remain useful long after the initial survey has been completed.

Historic districts inevitably change over time. Once their spatial information has been digitally documented, that data can become a lasting record for future restoration, research, exhibition, and public engagement.

Starting with projects such as Yanqingli, Tianbaonet continues to integrate handheld SLAM scanning, point cloud processing, 3D Gaussian Splatting, and 3D visualization to build a more complete approach to digital cultural heritage preservation.

From faster capture, to more realistic reconstruction, to long-term digital reuse, every field survey can become a reusable digital asset for the future.