NCCA - Personal Research by SELCUK ERGEN

 

Research Results

 

During my research I examined the logic of the L-Systems. I studied the rules the history and the use of the L-Systems. The aim of my research was trying to get some different visual effects instead using it for modelling trees as usual. After, practicing on tree and plant modelling I started to draw some sketches of patterns and imitate them in Houdini L-System SOP. The Results were convincing. I drew some basic shapes like cubes triangles and other geometric shapes and then tried to make them grow procedurally. During this process, I got experienced in rules and tried to model more complex systems.

 

The Following animations are some examples for the result of my research.

 

_________________________________________

 

01Growing Cubes

 

 

Lsystem Growing Cubes
Premise F[&A]+F[&A]+F[&A]+F[&A]
Rule 1 A=;F+FB
Rule 2 B=F^FZ
Rule 3 Z=F[&A]+F[&A]+F[&A]+F[&A]
Angle 90

 

- I Put some branches to the initial string to be able to create the cube geometry. (Volumed with PolyWire SOP instead of using the Tube mode of the L-System SOP in order to get a clean geometry)

 

 

____________________________________________

 

02Houdini Creature 01

 

 

Lsystem Houdini Creature 01
Premise F[&A]+F[&A]+F[&A]+F[&A]
Rule 1 A=;F+FB
Rule 2 B=F^FZ
Rule 3 Z=F[&A]+F[&A]+F[&A]+F[&A]
Angle 90 (Animated)
Angle Scale Sin($F*4)/3
Generations 5

 

- As it can be seen from the Rules they are exactly the same rules with the growing cubes example. However, I animated some parameters and values and add some expressions to get a different effect. The Result was surprisingly different from the 1st example.(Rendered with metaballs to get a jelly look)

 

 

 

___________________________________________

 

03Houdini Creature 02; Dynamic

 

 

Lsystem Houdini Creature 02
Premise F[&A]+F[&A]+F[&A]+F[&A]
Rule 1 A=;F+FB
Rule 2 B=F^FZ
Rule 3 Z=F[&A]+F[&A]+F[&A]+F[&A]
Angle 90 (Animated)
Angle Scale Sin($F*4)/3
Generations 5

 

For the sake of, getting cool effects, I decided to combine the L-system animations with Dynamics. I piped the previous animation into Dynamics and add some strings to the creature. The effect that I achieved was an organic looking underwater creature.

 

 

 

___________________________________________

 

04L-Machine

 

 

Lsystem L-Machine
Premise ^FFFF[&A]+FFFF[&A]+FFFF[&A]+FFFF[&A]
Rule 1 A=FFFX
Rule 2 X=&F[B]F[C]FF[D]
Rule 3 B=+ffF[G]
Rule 4 C=+F[G]
Rule 5 D=^(b)T(e)FF+F-FK
Rule 6 G=&(c)F(d)J
Angle 90
Variable b 20
Variable c sin($FF*20)+90
Variable d sin($FF*10)/9
Variable e sin($FF*10)*7

 

This System includes a little bit more rule than the previous ones. There is also Gravity factor involved and animated by e variable. Creating variables in the system gives many flexiblities in terms of having the control of the system.

 

 

 

___________________________________________

 

05Cage

 

 

Lsystem Cage
Premise ^F+(b)F[A]+(b)F[A]+(b)F[A]+(b)F[A]
+(b)F[A]+(b)F[A]+(b)F[A]+(b)F[A]
+(b)F[A]+(b)F[A]+(b)F[A]
Rule 1 A=&(c)FX
Rule 2 X: t<=3 =&FA
Rule 3 X: t>3 & t<5 =B
Rule 4 B=^F+(b)F[A]+(b)F[A]+(b)F[A]+(b)F[A]
+(b)F[A]+(b)F[A]+(b)F[A]+(b)F[A]
+(b)F[A]+(b)F[A]+(b)F[A]
Rule 5 X: t>6 =C
Rule 6 C=J
Angle 90
Variable b if($F<74, sin($FF*5)*30,5.20945
Variable c 45

 

- At this animation I used a lot of expression to get the slide and the other effects. Besides I had to use some L-System based if statements [ ex: X: t>3 ( if iteration count greaterthan 3 ) ]and external Houdini statements to stop the growing at some point and start another type of growing. And at the end of the animation I add some fruits ( J ) by using leaf inputs of the L-System SOP. Lastly, with a quick duplication I achieved a wierdly growing cage effect.

 

 

 

_____________________________________________

 

 

Conclusion:

 

As a conclusion, I realized that L-Systems will be a very powerful tool in terms of creating motion graphics style effects. Besides the architectural and plant side of the L-Systems it will definitly be a good solution to achieve various effects in Films and Commercials industry.

 

 

 

 

 

 

 

 

      Introduction         LSystems?         Houdini&LSystems          ResearchResults           Industry           References