lithium flowers bloom » simulation

Automating The Brush Stroke

L.J — Fri, 20 Nov 2009 18:40:40 +0000

Here’s a rough diagram of the drawing machine architecture that I have in mind. I’m building the components from bottom to top.

I moved on from the brush stroke and started to work on a set of drawing functions that incorporate the stroke.

Currently coverage:

moveTo,
lineTo,
rect,
circle

the moveTo function is necessary since the dynamics of the brush motion would depend on the last stroke, both position and speed.

currently i’m working on the curve function, it’s quite a challenge to get the brush movement natural enough and calculation is also dependent on the stroke length and brush size too. once this is done I think all basic drawing functions are covered for now and I will move onto the composition stage.

this is a simple test:

stroke update from Liangjie Xia on Vimeo.

Perlin Noise Flow Field and Smoky Ribbon

L.J — Wed, 04 Mar 2009 22:11:26 +0000

My take into the midterm for Nature of Code started from aimless playing with some old codes I made a couple of weeks ago. Not having a concrete idea of a “project” proposal, I decided to apply a Perlin Noise flow field to the fluid pluses I made last week, so that I need not necessarily introduce the mouse move to play with the field. The flow field reinitiates itself every 120 frames so that the particles keep moving and not getting too boring to look at.

Applet on OpenProcessing: http://openprocessing.org/visuals/?visualID=1094

After constructing the flow field, I came across Anthony Mattox’s Perlin Flow Ribbons which is amazingly attractive to me.Two levels of Perlin Noise field might be a good solution to make the field evolve more fluidly but I just didn’t do it… I just left the particles there and let them trace overtime. The results are … fairly good I shall say. Some of them do look pretty good, others are going bizarre due to lack of control. However the subtle motions overtime are charming to watch. I just sat there for hours staring at the screen (making screenshots) …

Applet on OpenProcessing: http://openprocessing.org/visuals/?visualID=1095

More Pic:

Playing with fluid simulation

L.J — Tue, 24 Feb 2009 01:45:31 +0000

As continuing playing with particle systems I came up this simple applet of fluid simuation app.

Play applet at http://leejayxia.com/processing/noc_fluid or http://openprocessing.org/visuals/?visualID=1047.

Floating bubbles

L.J — Sun, 22 Feb 2009 07:34:46 +0000

Assignment 2 for Nature of Code. Trying to simulate floating effect by creating gravity and buoyancy under the imaginative surface of water (in this case, the middle of the screen).

This is a practice of simulating the second Newton’s law by applying acceleration to the particle’s velocity other than directly changing the velocity or location.

Play applet at http://leejayxia.com/processing/noc_float/.

PCom Update: multiple serial input

L.J — Wed, 15 Oct 2008 06:11:52 +0000

I’ve been mostly working on viz class and pcom mid term over the weekend. One big thing is I once made the eight-buck-deal RF Link work in the studio, but never succeeded in testing again since I went back to the dorm. I used software serial library to utilize digital pins as serial input/output and leave the original serial port for computer monitoring, but the RL Links still feel like a black box to me. The transmitter side looks working perfectly while I hooked up a USB cable and tried to read the TX stream, however the receiver side keeps getting rubbish data. More efforts are to be invested on this issue!!

Just a quick update on the multi-serial-input, shown as the video below (yes I still love my force sensors):

It’s pretty simple, just using two serial inputs. But the concept of encoding data and protocol is pretty clear.

Arduino Code:

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int leftPin = 4;
int rightPin = 5;
int leftValue,rightValue;

void setup()
{
beginSerial(9600); //set up communication back to pc
}

void loop()
{
leftValue = analogRead(leftPin);
rightValue = analogRead(rightPin);

//if (abs(leftValue - rightValue) > 50)
//{
Serial.print(leftValue,DEC);
Serial.print(44,BYTE);
Serial.print(rightValue,DEC);
Serial.print(44,BYTE);
Serial.println();
//}
}

Processing Code:

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import processing.serial.*;

Serial myPort;
String data;
int leftValue = 0;
int rightValue = 0;

void setup()
{
size(800, 600, P3D);
directionalLight(126, 126, 126, 0, 0, -1);
ambientLight(102, 102, 102);
noStroke();
myPort = new Serial(this, Serial.list()[0], 9600);
ellipseMode(CENTER);
}

void draw()
{
background(0);
float leftR = map(leftValue,0,1023,0,PI/2);
float rightR = map(rightValue,0,1023,0,PI/2);

translate(width/2, height/2);

rotateX(-PI/12);
rotateZ(rightR - leftR);
stroke(160,10);
fill(150,150,150,90);
box(500,10,100);
translate(0,10);

noStroke();
fill(255,0,0);
translate(map(rightValue - leftValue,-1023,1023,-250,250),-25);
sphere(10);
}

void serialEvent(Serial p) {
String input = p.readStringUntil(10); //make sure you return (Ascii 13) at the end of your transmission
if (input != null)
{
String[] parts = input.split(","); //this will only work if you put commas (Ascii 44) between things in your transmission

if (parts.length >= 2)
{
//println("Raw Input: " + input);
if (abs(int(parts[0]) - leftValue) > 10)
{
leftValue = int(parts[0]);
}
if (abs(int(parts[1]) - rightValue) > 10)
{
rightValue = int(parts[1]);
}
}
}
}