14 Best Practices in Scan to BIM
Scan to BIM
Scan to BIM or Point Cloud to BIM is the most accurate method to create As-Built BIM Models of any existing Buildings or Interior spaces. Not all Laser Scans are equal. A lot of times there are Blind Spots or missing data. Incomplete low-quality, low-density Black & White can be very difficult to Model accurately and can sometimes take a long time to model as the modeler needs to decipher and interpret missing or low-resolution Point Cloud Data. This article describes best practices you should follow to would help you get the best results
Scan to BIM Process
let us first understand the Process. Scan to BIM is essentially composed to three stages
- On-Site Laser Scanning using Laser Scanning Camera
- Registering Raw Laser Scans
- Converting Registered Laser Scans to BIM
This is the starting point of your Project
- Clearly define Scope of Work and level of Detail that is needed for the Project.
- Define the Scanning Process and methodology to be adopted before sending in field staff.
- Use High-Quality Scanners that can produce high-density color Point Cloud Data. High-Density Color Point Cloud Data is critical for an accurate Scan to BIM Model and can help you save. This is because of clarity in data, helps reduce Modeling time and as a result lower cost.
- Plan your scanning Process. Identify Camera Positions and ensure Circles of each Camera overlap
- Support Point Cloud Data with Photographs. and 360 Walkthroughs. This helps modelers understand space and elements that are unclear in Point Cloud
- Field Notes can help in accuracy. Not all information is clear in Scan data, Field Notes take a higher priority over Point Cloud and result in a more accurate BIM Model
Each Project will have multiple scans in order to scan a Building or an Interior space. Autodesk Recap Pro can take this raw data and automatically register the raw data.
- Number the scans sequentially. This helps in aligning scans properly.
This is the final step in Scan to BIM process. Now that you have Scan data. Import it into Revit. The following steps will be helpful in accurately modeling from Point Cloud.
- Checkout Scope of work and LOD level that is required for your BIM Model
- Establish Survey point if available in your scan Data
- Once your Point Cloud is in Revit, Pin it
- Setup Levels. When you import Point Cloud, you will need to establish levels. Your level 1 Plan may not show anything. Use 3D Elevation Views to establish levels.
- Adjust View Depths. Without adjusting View Depths, you may see a huge amount of Points and these may become confusing
- Cross check your model against Photographs, Field Notes and 360 Walkthrough.
- If 360 Walkthrough is unavailable, use Navisworks walkrhrough