Project 2 - L-Systems

Description

For my L-System project I wanted to use real world lightning data from various cities around the world, to try and re-create lightning. Using L-Systems, Houdini and the data provided to me by the Weather Channel, I set off to accomplish this task!

Method
For this project I was able to receive data from the Weather Channel's national and global archives. The cities chosen were:

• Anchorage, Alaska, USA - 100 miles - 2012 to 2013
• Bogota, Colombia - 100 miles - 2013
• Death Valley, California, USA - 100 miles - 2013
• Houston, Texas, USA - 100 miles - 2013
• Kuala Lumpur, Malaysia - 100 miles - 2013
• Munich, Germany - 100 miles - 2013

 The data contained: 

• date and time
• length in time of the lightning strike
• lat/long coordinates
• polarity of the lightning strike
• amplitude of the lightning strike

1. I began by narrowing my data down to 100 lightning strikes per city, chosen at random (some cities had up to 200,000 in one month!). Lightning chosen was based on the months with the most activity for each city.
2. I then began creating a base L-System that would get me close to the look and feel of a lightning strike.
3. Next I brought in the lat/long coordinates of lightning data for each city and mapped an L-system to each point.
4. I then used the length in time of the each lightning strike to dynamically control the number of generations each lightning strike would have. Quick lightning strikes would have fewer generations compared to longer lightning strikes.
5. Next I used the polarity of each lightning strike to control whether the lightning strike was more of a large individual bolt, versus a more webby/spread out lightning bolt.
6. Next, I used the Amplitude as well as the Polarity to control 3 different branching angle variables to determine branching at various stages in my L-System construction (implemented in Rules 1, 2, and 3).
7. Finally, I used the length in time again to control the thickness of the lightning strike branches. You'll notice that individual bolts(faster strikes) are fatter than the larger, more webby strikes, where the branches taper off to a smaller radius.

Presentation

I imagine these images as being printed out on 18x24 paper and presented with a small card detailing the City used, radius sampled around the city, and year the data was taken from.

Results

Cities presented in alphabetical order. Anchorage, Bogota, Death Valley, Houston, Kuala Lumpur, Munich.

Process Images

Below, actual lightning strike points and L-systems are shown for each city. The L-Systems are 3D.

Anchorage

Bogota

Death Valley

Houston

Kuala Lumpur

Munich

This final image here just blows my mind. This is the lat/long lightning data for Houston in May of 2013. 207,163 lightning strikes in one month! The next highest city was Bogota in October at 66,000 strikes.