The Esri-Autodesk partnership continues to advance the AEC industry with data interoperability, workflow optimizations and enhanced visualization and analysis tools. This year, students in the Building Information Modeling Management Program at George Brown College worked with Esri Canada Education and Research to explore BIM and CAD integration within ArcGIS Pro. Their project assists in advancing our knowledge around best practices for working with complex construction data.
In 2017, Esri and Autodesk announced a formal partnership to strengthen the ties between GIS and computer aided drafting/design and computer aided engineering (CAD/CAE ). For many who work in the architecture, engineering and construction (AEC) industry, this was a major announcement.
In a typical CAD-based system, data exist in a user coordinate system (UCS) or a world coordinate system (WCS). These coordinate systems describe points relative to the object being drawn in CAD and are not relative to any location in the real world. This is useful when creating drawings with a high level of detail as it allows for simple entry of measurements and relative distances, but it means the drawing cannot be easily placed on a world map. Building Information Modeling (BIM) is a process that evolved from CAD. A BIM process is used for managing and creating information related to construction projects and project lifecycles, and BIM data consist of 3D objects and detailed structural attribute data. Like CAD data, BIM data also generally work in a coordinate system that places objects relative to other objects in a view, and not within real-world context. Relative to GIS, CAD and BIM systems generally have more drawing tools, line properties and structural building objects to create complex, detailed drawings for engineering, architectural and industrial design applications.
In contrast, a GIS-based system utilizes a geographic coordinate system (GCS) or a Projected Coordinate System. These coordinate systems place information within the context of the real world. A GIS coordinate system can handle large amounts of information, even data at a global scale, and a GIS platform provides the tools to measure, analyze and visualize information across multiple scales on earth. GIS also contains a backend database, meaning that all points, lines, and polygons, as well as associated attribute data can be selected, queried and analyzed in a visual mapping environment.
The partnership between Esri and Autodesk paves the way for new integration tools between a CAD-based application and a GIS-based system, enabling more fluid workflows. Esri now provides the tools to import CAD and Autodesk Revit data seamlessly into ArcGIS Pro for visualization and analysis, and the new Building Explorer tool provides a more interactive way to explore a Building Information Model (BIM) Revit file in ArcGIS Online. The tool allows users to explore building floors and specific building details, such as walls, lights, windows and doors, as well as Revit layers within the context of an online 3D web scene.
The Esri-Autodesk partnership has garnered the attention of colleges and universities that teach skills and concepts in the AEC industry. Recently, I worked with Petro Karanxha, a professor at George Brown’s BIM Management program, to support six students as they completed their final capstone research project that focused on Esri-Autodesk integrations. Willa Chu, Mahsa Motamed, Lucas Rigotto, Danyal Sandha, Mahtab Taheri and Sofiya Vadsariya spent their final semester researching ArcGIS workflows with BIM data as they relate to building and property mapping. This exploratory research project had three phases: Project Initiation, Process and Analysis, and Research Findings.
To start the project, the students defined a series of goals that would allow for Esri and Autodesk CAD and BIM tool exploration. They also established a 13-week timeline and created objectives for project deliverables. The students were trying to complete the following goals through this project:
- Model several campus buildings at George Brown using Autodesk software and import the finished models into ArcGIS Pro while maintaining data accuracy and layer properties, such as wall width, wall type, and room type.
- Evaluate the workflows involved with importing CAD and Revit data into ArcGIS Pro and document best practices for future workflows.
- Create attributes for interior building features to test the model within a facilities management and operations system.
- Create web scenes for sharing all models within an organization.
Process and Analysis
To create the 3D campus buildings, the models were first created in AutoCAD. Since the students were able to obtain original CAD drawings from the campus facilities office, the model creation workflow involved data cleanup, unit conversion, data validation, and layer organization.
To create models, CAD data were cleaned, scaled and organized using AutoCAD.
The students brought the CAD data into ArcGIS Pro and georeferenced and projected them to an appropriate coordinate system. They ran several geoprocessing tools to generate 2D building features, including Feature to Polygon to create polygon features from CAD lines, as well as CAD to Geodatabase to convert and import the CAD linework into a geodatabase. The Union tool was also used to create a singular feature layer without conflicting polygons.
Once 2D features were created, the students extruded the features to the correct height relative to the ground surface. Initial attempts at generating 3D objects from the 2D features produced unsatisfactory results, so the students had to decide whether it was worth their while continuing to work with CAD data or try a different approach.
The group decided that they would start the process again using Revit, rather than AutoCAD. The students had more familiarity with Revit and knew that they would be able to generate 3D BIM objects quickly and efficiently using the software. Once again, CAD data were imported, into Revit this time, to act as a reference layer. The students modelled out their buildings using Revit architectural elements to create walls and rooms, and used Room Tags to label rooms with their names and space-use details.
Standardized Revit elements include generic floors, basic walls of different thicknesses, and single and double doors of different dimensions.
This time, when the students imported the model into ArcGIS Pro, they saw significant improvements in data quality, representation and layer organization when compared with the previous CAD import process. The Revit import tools in ArcGIS Pro provided a more efficient workflow and produced better results. The students also realized the potential for future data import through the Revit-to-ArcGIS Pro workflow, whereby electrical, mechanical, structural and underground features could be imported to enhance the campus architectural model.
Revit data for the campus building were imported, projected and georeferenced in ArcGIS Pro.
Revit data after ArcGIS Pro symbology was applied.
The process for properly importing Revit BIM data into ArcGIS Pro involved georeferencing the models and defining a proper projection. As of version 2.6, ArcGIS Pro includes a new feature that automatically imports Revit material libraries, so textures were quickly imported and visualized in the 3D scene. After the models were properly placed in a scene, they were exported as a Building Scene Layer Package and published into ArcGIS Online for visualization. Surrounding 3D context data and custom elevations obtained from Toronto’s Open Data Portal were included, and the final 3D web scene was shared with the George Brown organization in ArcGIS Online.
Revit data after they have been symbolized in ArcGIS Pro and placed in a 3D scene.
The students concluded that Revit to ArcGIS Pro was much more efficient than a CAD to ArcGIS Pro workflow when generating 3D building interiors and exteriors.
In addition to generating a 3D model that was published on ArcGIS Online, the students explored opportunities for importing this model into ArcGIS Urban and ArcGIS CityEngine for more advanced visualizations, and for modelling future development scenarios around the campus. The students also tested out a variety of 3D viewers in ArcGIS Online, by creating Web Scenes, by visualizations through the Experience Builder, and by adjusting settings within the Web AppBuilder. The Building Explorer tool proved to be especially useful, since it allowed for the visualization of campus buildings on a floor-by-floor basis and it clearly highlighted interior spaces.
As Esri and Autodesk continue to work together to improve connectivity between CAD and GIS-based datasets, it is important to realize that these research projects are not only about testing workflows and data interoperability. The students who work on these projects are our future leaders in the AEC sector. These projects expose them to the opportunities, challenges, and complexities of this ever evolving but incredibly important industry.
For more information on this George Brown project, you can check out the ArcGIS Integration with BIM Data in Property Mapping and Data Management report.
For additional information about importing CAD and BIM into ArcGIS Pro, check out the following resources:
What is Revit Data?
About the Project Participants
Willa Chu, Mahsa Motamed, Lucas Rigotto, Danyal Sandha, Mahtab Taheri and Sofiya Vadsariya are post-graduate students in the Building Information Modelling Management Program (BIM) at George Brown College. Over the course of the year, these students focused on gaining hands-on training to learn industry-leading skills that can be applied to all phases of building construction, procurement, operation and design in the Architecture, Engineering and Construction (AEC) industry.
Petro Karanxha is a professor in the Building Information Modelling Management Program at the Angelo DelZotto School of Construction Management at George Brown College in Toronto, Canada. He teaches BIM Management, Computer Applied Construction Practices, BIM Software Integration, BIM Implementation Strategies, and BIM Project Planning. Petro’s areas of specialization are in Building Information Modelling, BIM Management, Navisworks, Revit, SketchUp and LiDAR technologies.
This post was translated to French and can be viewed here.