# Changing values?

Hi is anybody clever enough to explain to me why this program creates changing values , I realize that it resets the arrays with each draw loop , But why are they different ?

please format code with </> button * homework policy * asking questions

// TUBULAR FORM USING REFORMED ARRAYS ****** NIGEL S WOOLARD

int r = 100;
int r2 = 200;

int np = 12;

int cl = 100;
float anglestep = radians(360/np); // ALSO TRIED WITH PI VALUES

float[]PX1 = new float [np];
float[]PY1 = new float[np];
float[]PZ1 = new float[np];

float[]PX2 = new float[np];
float[]PY2 = new float[np];
float[]PZ2 = new float[np];

void setup() {

size(600, 600, P3D);
}

void draw() {

BACKGROUND();

CREATETUBE();

DRAWTUBE();

}

void CREATETUBE() {

noStroke();

beginShape(TRIANGLE_STRIP);

for (int i=0; i<np; i++) {

``````float px1 = sin(angle/np)*r;

float py1 = cos(angle/np)*r;

float pz1 = 0;

PX1[i] = px1;
PY1[i] = py1;
PZ1[i] = pz1;

//vertex (px1, py1, pz1);

float px2 = px1;

float py2 = py1;

float pz2  = pz1;

px2 = sin(angle/np)*r2;

py2 = cos(angle/np)*r2;

pz2 = 0+cl;

PX2[i] = px2;
PY2[i] = py2;
PZ2[i] = pz2;
``````

// vertex (px2, py2, pz2);

``````angle = angle + anglestep;
``````

}

endShape();
}

//****************************************************************************

void DRAWTUBE(){

translate(300,300,0);
beginShape();
for (int i=0;i<np;i++){

``````    stroke(#FF0000);
vertex (PX1[i],PY1[i],PZ1[i]);
stroke(#FFEA00);
vertex (PX2[i],PY2[i],PZ2[i]);
}

endShape();}
``````

//*****************************************************************************

void BACKGROUND(){

fill(#FF8000);

}

in my opinion this might be it

I rewrote your Sketch a bit

I think one issue was that you had `float px1 = sin(angle/np)*r;` here.
I think this should be `float px1 = cos(angle)*r;` (without “`/np`”)

I also set angle to 0 in draw()

Chrisir

``````
// TUBULAR FORM USING REFORMED ARRAYS ****** NIGEL S WOOLARD

final int r = 100;
final int r2 = 200;

final int np = 90;

final int cl = 100;
final float anglestep = radians(360/np); // ALSO TRIED WITH PI VALUES

float[]PX1 = new float[np];
float[]PY1 = new float[np];
float[]PZ1 = new float[np];

float[]PX2 = new float[np];
float[]PY2 = new float[np];
float[]PZ2 = new float[np];

void setup() {
size(600, 600, P3D);
}

void draw() {
BACKGROUND();

angle=0;
CREATETUBE();
DRAWTUBE();
}

//--------------------------------------------------------------

void CREATETUBE() {
for (int i=0; i<np; i++) {

PX1[i] = cos(angle)*r;
PY1[i] = sin(angle)*r;
PZ1[i] = 0;

PX2[i] = cos(angle)*r2;
PY2[i] = sin(angle)*r2;
PZ2[i] = cl;

angle += anglestep;
}
}

//****************************************************************************

void DRAWTUBE() {
translate(300, 300, 0);
beginShape();
for (int i=0; i<np; i++) {
stroke(#FF0000);
vertex (PX1[i], PY1[i], PZ1[i]);
stroke(#FFEA00);
vertex (PX2[i], PY2[i], PZ2[i]);
}
endShape();
}

//*****************************************************************************

void BACKGROUND() {
fill(#FF8000);
}
//

``````

Thanks Chris that’s great !

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