This example is for Processing 3+. If you have a previous version, use the examples included with your software. If you see any errors or have suggestions, please let us know.

Soft Body by Ira Greenberg.

Softbody dynamics simulation using curveVertex() and curveTightness().

// center point
float centerX = 0, centerY = 0;

float radius = 45, rotAngle = -90;
float accelX, accelY;
float springing = .0009, damping = .98;

//corner nodes
int nodes = 5;
float nodeStartX[] = new float[nodes];
float nodeStartY[] = new float[nodes];
float[]nodeX = new float[nodes];
float[]nodeY = new float[nodes];
float[]angle = new float[nodes];
float[]frequency = new float[nodes];

// soft-body dynamics
float organicConstant = 1;

void setup() {
size(640, 360);
//center shape in window
centerX = width/2;
centerY = height/2;
// iniitalize frequencies for corner nodes
for (int i=0; i<nodes; i++){
frequency[i] = random(5, 12);
}
noStroke();
frameRate(30);
}

void draw() {
fill(0, 100);
rect(0,0,width, height);
drawShape();
moveShape();
}

void drawShape() {
//  calculate node  starting positions
for (int i=0; i<nodes; i++){
rotAngle += 360.0/nodes;
}

// draw polygon
curveTightness(organicConstant);
fill(255);
beginShape();
for (int i=0; i<nodes; i++){
curveVertex(nodeX[i], nodeY[i]);
}
for (int i=0; i<nodes-1; i++){
curveVertex(nodeX[i], nodeY[i]);
}
endShape(CLOSE);
}

void moveShape() {
//move center point
float deltaX = mouseX-centerX;
float deltaY = mouseY-centerY;

// create springing effect
deltaX *= springing;
deltaY *= springing;
accelX += deltaX;
accelY += deltaY;

// move predator's center
centerX += accelX;
centerY += accelY;

// slow down springing
accelX *= damping;
accelY *= damping;

// change curve tightness
organicConstant = 1-((abs(accelX)+abs(accelY))*.1);

//move nodes
for (int i=0; i<nodes; i++){