This is a quick tutorial explaining the following:
- How to take your building envelope or facade into Vasari.
- Run daylight analysis.
- Save the data
- Import it back into GH
- Apply the data back onto the model.
First you need to download Vasari from Autodesk. Currently the program is free and is still in BETA stage:
- http://autodeskvasari.com
Next, we will be using a GrassHopper plugin I developed to make importing the data easier for those not accustomed to importing and parsing raw data. The plugin is part of a larger plugin set called Mosquito:
- http://www.ceedstudio.com/ceed3/mosquito/
You can also download the files I used for this tutorial from the following link:
Part 1: Exporting models from Rhino
Create a simple massing that you can export to Vasari.
Notice that I have also modeled a flat ground plane. In order to obtain useful data, I suggest adding a ground plane for your model which can receive shadow data from your building mass. Without a ground plane you will not get any ground/site data.
In order to for Vasari to read your model it needs to be exported in .SAT format.
Part 2: Importing and Placing the model in Vasari
Open Vasari and choose the Metric you will be working with:
In order for everything to go smoothly, we need to create a mass in Vasari that will hold our model. Importing the SAT file directly sometimes leads to problems.
Create a new mass:
Import CAD model from the main menu and choose the correct units:
If everything went well you should see your model in the view port. If your model was in the incorrect units , or too tiny, it will not show up in the viewport.
Finish Editing the mass:
Part 3: Running Daylight Analysis
Before we run a simulation , you need to make sure that "Show Mass Form" is highlighted.
Run a test daylight simulation by clicking the "Solar Radiation" button.
A menu will pop up. You need to push the slider to "High Resolution" and select the correct "Unit" size.
Click "Analyze" : DO NOT close the window
The result should be visible in your viewport.
Click "Export" and save the .CSV file to your hard drive.
Sunlight
If you would like to see a preview of the sun direction click the menu in the bottom left of the window:
You should now see the sun in the viewport and have the ability to change the time of day and season:
Part 4: Importing Data
In order to import the data from Vasari, you will need to make use of the "Mosquito" plugin package from my website. Please refer to the grasshopper website to find out how to install plugins. If you have installed the "Mosquito" plugin sweet properly then you should see the following menu in Grasshopper:
In order to pull the exported data into GH you will need two plugins, the "File path" component and the "Vasari" component.
P = Points
A = Analysis
N = Normals
Section 2: Using the data to manipulate geometry
This section describes how to actually utilize the Points and Analysis results.
Part 5: Rescaling the model
Once the correct file is referenced you should have new points appear in your Rhino viewport. However, if you did not import/export with the correct units your points will be very small compare to the original model , or not line up exactly as they should. In the image below you can see that the points came in as a tiny cluster in the bottom right corner.
In order to solve this we use the "Scale" component. The points from the Vasari component go into the "G" (geometry) input of the scale component. The "F" input is the scale factor and can be used with a slider to adjust the size of your geometry. I found that 300-310 for this example.
Part 6: Move the data
Now things look better, however, the model and Vasari data still do not line up. To move the points into the correct location we will use the "Move" component. The component requires a vector, so it knows where to move the collection of points from and to.
Create the points you would like to move from and to and reference them into Grasshopper. Then create a "Vector" component and plug those points in respectively.
The create a "Move" component and plug the geometry from the "Scale" components output into the "Move" components geometry input. Use the vector we just created form the translation vector in the "Move" component.
You should now be able to adjust the position of the Vasari data by moving your "Vector" components reference points in the Rhino viewport.
Part 7: Applying the data to the model
Now that the model and Vasari data line up, we can apply the data. First however, we need something to apply the data to. Select your building envelope and reference it into GH using the "Surface" component.
Now you can use the setup as illustrated below to subdivide the surface into multiple panels. To do so, we use the "Divide Domain" and "IsoTrim" components.
Part 8: Center Points
We want to find the closest Vasari data point for every panel. We do this by measuring the proximity of the center of each panel to each Vasari data point.
Use the "Area" component on the "IsoTrim" output to get the center point of each panel.
Part 9: Matching Vasari data points
In order to find the Vasari data point that relates the closest to each panel we use the "Closest Point" component. This component goes through each point in a given list and finds the closest Vasari point.
First flatten all the outputs from the Vasari component. Then create a "Closest Point" component and hook them up as illustrated below. This is needed in order to extract the index of the Vasari data.
Part 10: Vasari Analysis Data to Color values
Lets use the Vasari analysis data to color the panels on our facade. In order to do this we use three components:
The Bounds components: This determines the highest and lowest values from the Analysis data.
The Deconstruct components: This breaks breaks the bounds into the "Start" and "End" values, so that we can tell the "Gradient" component the bounds.
The Gradient component: The gradient component requires a start (L0) and an end (L1) value. These values determine the extremes, low(green) and high (red).
Vasari's data "A" is fed into the "t" input of the gradient component. All this data is mapped along the gradient between the two extremes.
The result is a list of colors in RGB format.
Now we can use the index values from the "Closest Point" component to extract the matching color value for each panel.
You should now have the following result.
If you would like to increase or decrease the number of panels use a pair of sliders on the "IsoTrim" component that we created earlier in our definition.
Part 11: Driving the panel size by light intensity
In addition to color we can use the values to drive the size of the panels. Where ever the intensity readings were low, the panels will shrink to let more light through the facade.
Start by creating a "Scale" component. Use the center point from the "Area" component as the centre for the "Scale" component.
Plug the panels from the "IsoTrim" component into "G" (geometry).
The next part is fairly tricky, you may need to open the file and explore the definition closer.
We use the index from the "Closest Point" component along with an "Index Item" component to pull out the relevant raw Analysis data values form Vasari.
The "ReMap" component is then used to remap these values between 0.460 and 1.0.
This result is then used for the scale factor ("F") .
