Using photogrammetry for Scan-to-BIM Workflows

Published in BIM

April 16, 2024

2 min read

Harnessing Photogrammetry for Scan-to-BIM Workflows: A Comprehensive Guide

Introduction

Building Information Modeling (BIM) represents a revolutionary approach to architectural and construction planning, offering a digital representation of physical and functional characteristics of a facility. Photogrammetry, a technology that converts photographs into precise 3D models, is pivotal in this innovation. This article explores the Scan-to-BIM workflow using photogrammetry, discussing its applications, benefits, and step-by-step process.

What is Scan to BIM?

Scan-to-BIM is a process where digital information about a built asset is collected through scanning technologies (such as laser scanners or photogrammetry) and then integrated into a BIM software environment. This method is especially useful for retrofitting, refurbishment projects, and historical documentation of existing conditions.

Why use Photogrammetry in scan to BIM workflows?

Photogrammetry solutions allow users to create high-fidelity 3D models from simple photographs. These tools stand out due to their ability to handle enormous volumes of data, providing engineers, architects, and constructors with accurate, scalable models that are essential for a BIM environment.

Comparing Photogrammetry to traditional LIDAR in Scan-to-BIM Workflows

Below is a table comparing the benefits of photogrammetry versus traditional Scan-to-BIM processes, highlighting key advantages of each:

Feature	Photogrammetry	Traditional Scan-to-BIM
Accuracy	High, depending on image quality	Very high
Cost	Generally lower	Higher, due to equipment
Speed of Data Capture	Fast, can cover large areas quickly	Slower, but thorough
Ease of Use	User-friendly for non-experts	Requires technical skill
Flexibility	High, works well in difficult terrain	Limited by access and setup
Data Volume Management	Efficient, handles large datasets	Intensive data handling

The Scan-to-BIM Workflow with Photogrammetry

The workflow for converting scan data to BIM models using photogrammetry involves several key steps:

Data Collection: This initial phase involves capturing high-quality images of the physical site from multiple angles. The overlapping photographs are crucial for creating a comprehensive view of the area.
Data Processing in Photogrammetry Software: Once the photographs are collected, photogrammetry software processes the images to construct a precise 3D model. The software uses advanced algorithms to stitch together the data, creating a coherent digital representation of the scanned environment.
Model Refinement: The raw 3D model generated may require further refinement to be fully functional within a BIM environment. This includes enhancing the geometry, adding metadata, and segmenting the model based on different building components and systems.
Integration into BIM Software: After refinement, the model is imported into BIM software. At this stage, additional BIM elements like structural, electrical, and plumbing systems are integrated into the 3D model.
Analysis and Utilization: The final BIM model is not just a static representation but a dynamic environment that stakeholders can interact with. Users can conduct various analyses such as structural assessments, energy performance simulations, and more. This model serves as a collaborative tool throughout the lifecycle of the building, from design and construction to operation and maintenance.

Benefits of Using Photogrammetry in Scan-to-BIM

Accuracy and Precision: Photogrammetry provides exceptionally accurate 3D models even when working with complex geometries and large datasets.
Efficiency: The ability to handle vast amounts of data quickly reduces the time required for model creation, speeding up the overall project timeline.
Cost-effectiveness: Using digital models can significantly reduce the need for physical site visits and manual measurements, lowering project costs.
Enhanced Collaboration: BIM models created with photogrammetry can be easily shared and accessed by various stakeholders across different locations, enhancing collaborative efforts.

Conclusion

The integration of photogrammetry into Scan-to-BIM workflows represents a significant advancement in the field of construction and architectural design. By efficiently turning raw data into detailed, actionable BIM models, photogrammetry not only streamlines the design and construction processes but also enhances the maintenance and operation phases of a facility’s lifecycle. As technology progresses