GIS to BIM – ARCHICAD & Grasshopper
We had a busy period during the past two months, so apologies for not sharing anything lately after the updates of the Ramp Object development. Today we are going to talk about GIS and BIM. In this article we will share our experience importing GIS data into BIM using the connection in between Grasshopper and ARCHICAD. Later we will compare the result obtained with other GIS sources.
But before we start let me introduce this topic. What is GIS and why is it so cool?
Most of you probably know already what GIS is about and maybe even used and implemented in your own work-flow. For those who doesn’t know, a GIS (Geographic Information System) consist of a system that integrates and handles spatial and geographic data.
Last month we were invited to the Geospatial World Forum 2019 that took place in Amsterdam, to share our experience combining BIM and GIS. This is a world wide forum that takes place every year to connect professionals related to the geographical world.
Something I didn’t know about this international community / environment of professionals and knowledge is how much it can be applied to very different fields of study.
This data that we are talking about here can be materialized in different formats such as 2D Maps, 3D terrains, Satellite images, point clouds, etc… But it can be also socioeconomic data of populations and cities, cadastre information, financial information, weather data, energy usage related information, and so on. As you see the list of different types of data could even go longer. As I mentioned, large amount of fields of study can benefit from the GIS data environment.
There are many ways of using and accessing this data. There are also GIS applications that allow to extract and analyze this data for different purposes such as infrastructure development, social and economical analysis, construction and development simulation, analyzing urban models, terrain studies and even disaster predictions and emergency interventions…
For architecture and construction the most immediate application would be to analyze and understand the surroundings and geographic conditions of a terrain. In our industry we have been actually using this type of information very often, every time we did a site or terrain survey getting the information in format of CAD 2D-3D, point cloud, Satellite images or weather information.
Here is a list of platforms and applications from which these GIS Data and files can be accessed that are very useful for Architects and professionals of the construction industry. This data is very relevant both for construction and infrastructure projects.
Open Street Maps, ArcGIS, USGS, CADMAPPER, OpenTopography, GeoNetwork, Google Earth and more.
Some of these are open source platforms from which we can retrieve data and files for free. Some of them are applications which we need to subscribe to be able to use them.
There is also many different workflows and applications to integrate this data into 3D tools and BIM. The most famous one for Architects and designers I guess is the connection in between Sketchup and Google Earth. I even had the chance to meet the guys from AgiliCity, who develop Modelur for Sketchup, which is a really cool plug-in very useful for urban projects.
ArcGIS from Esri has connectivity with some BIM solutions. But there are many other platforms that can act as an interface to combine GIS data with 3D models of many different formats. During the Forum we could get to know more about some of these platforms like AW3D, which provides a platform to combine 3D models with terrain models to generate Digital Twins and much more.
Let’s get into the point of this article which is our small contribution to Architecture workflows: Connecting BIM and GIS using Grasshopper and ARCHICAD. As I said, there are many different developments in this field and our’s is just a particular workflow that allow us to enhance our methodologies to develop Architecture projects using BIM.
Basically we use the connection between Grasshopper and ARCHICAD to extract this data and integrate it into our BIM models. There is this great set of tools for Grasshopper which is called Elk, it can be downloaded from Food4Rhino website. With this set of commands we access the data from OpenStreetMap website (OSM files), USGS (DEM files) and Topographic data in GeoTIFF format. In this exercise we used as a source of data OSM files from OpenStreetMap website.
First we should download the .OSM and GeoTIFF files form the location we are interested. Then we can start the process in Grasshopper using Elk. Have look to the images below to see the first 5 steps:
In a few simple steps we just generated automatically a 3D terrain and a 2D map of the city of Hong Kong. The same can be done for many other cities and locations in the world.
Apart from this spatial data that generates 2D and 3D information, there is a huge information structure embedded in this files. It is not that easy to be accessed but it is there for us to explore. Have a look to the images below.
In this case we tried to retrieve the information related to the function of every building to categorize our 3D model of this part of the city of Hong Kong. But this data is not homogeneously available for all cities in the world. In the case of Hong Kong we could’t extract the data accurately for every block, just a few of them.
Then it comes into the game the connection with ARCHICAD and Grasshopper. What we do is to extract a set of polylines from the geometry we obtained from the previous steps to create a set of groups of Slabs in our ARCHICAD model. With the capacity of ARCHICAD to handle big BIM models, we can store a part of the dense urban Fabric of the city of Hong Kong for any project we would like to work on.
And this is how this part of the city looks like in our ARCHICAD Model:
It is very useful to explore the different sites of the city for particular projects. We can understand a great deal of information such as: Views from a particular site or building, density of the area of the project, connectivity through the city, base to produce reliable diagrams in 3D, city environment to develop Sun Studies at a very accurate level…
The same workflow can be applied to different cities. It might be the case that this 3D model is not 100% accurate at the detail level. It does worth to check other sources or even compare with local surveys of the city. But I must say that for the case of Hong Kong, to a scale of 1:200 or 1:500, the size of the buildings, the heights, the position and the terrain is quite accurate.
After implementing this workflow using parts of the urban fabric of 3 different cities: New York, Madrid and Hong Kong; we decided to compare the result of these models with those generated from two other sources: CADMAPPER and Google Earth. I am sure you are familiar with the last one. We usually import models from Google Earth into ARCHICAD through Sketchup. Regarding CADMAPPER, in case you haven’t explore the huge potential of this platform, I suggest you have a look to this awesome video of ContraBIM in Youtube to learn more about how to connect this data into ARCHICAD.
As you can see in the images above, the different cities we have tried have different amount of 2D and 3D data available depending on which platform. Is good to compare the results when we use thee tools to understand the level of accuracy of the result.
There are other useful set of tools for Grasshopper which we haven’t use in this exercise, like for example Meerkat. which allow us to import the information contained in shape files. We hope to start using these tools as well soon. I am quite sure some users may have developed already their own workflows with these tools.
I hope you find this article interesting. I also hope you start testing some of this tools and possibilities that the GIS world can offer to our Architecture work-flow.
Just to finish the article, I would like to summarize which are in my opinion the most relevant ways in which GIS can Boost the Architecture practice:
- Line of Sight
- Exposure to Noise
- Development Planning
- Crowd Simulation
- Solar Exposure
- City Engine
- Pedestrian Behavior
- Shadow Analysis
- Parking Availability
- Tangible Landscape
- Propagation of Noise in Urban Environments
Please feel free to ask us any further question regarding this workflow.
Let’s keep the conversation alive!