ofLine and perlin noise


I am trying to implement perlin noise on a line.

I’ve divided 2 vector’s length with sample point that I want and re draw it for each section as much as sample point divided.

    void testApp::lifeStream( ofVec3f vec1, ofVec3f vec2, int stepsize ){
// perlin noise obj
        msa::Perlin pNoise2( OCCTAVE, FREQ, AMPLITUDE, ofRandom(123) );
// front line keep
        ofLine( vec1, vec2 * 1/stepsize + pNoise2.get(1, 2, 3) );
        vec1 = vec2 * 1/stepsize + pNoise2.get(1, 2, 3);
        for (int i = 2; i < stepsize; i++) {
            msa::Perlin pNoise( OCCTAVE, FREQ, AMPLITUDE, ofRandom(0, i+123) );
            ofLine( vec1, vec2 * i/stepsize + pNoise.get(5 * i, 5 * i) );
            vec1 = vec2 * i/stepsize + pNoise.get(5 * i, 5 * i);
// end line keep
        ofLine( vec1, vec2 );

and then added perlin noise to it with ofxMSAPerlin but I am wondering if that is write way to create noised line in OF?

Hey @fkkcloud, what exactly are you trying to achieve with applying perlin noise to a line? I’m a little confused by the fact that you change your seed value on every iteration of your for loop. That appears to me like it would defeat the purpose of using perlin noise?

As for drawing lines that are composed of many line segments - have you used ofPolyline before (doc page)? It would allow you to draw curved line segments (using curveTo(...)) instead of only being able to only draw straight line segments with ofLine.

It also has methods like getPointAtPercent(...) and getPointAtLength(...) that would allow you to sample evenly along your ofPolyline. The way that you are using stepsize doesn’t appear to guarantee that you would be sampling your line evenly between vec1 and vec2 (unless when you call lifeStream, you are setting your stepsize to be the euclidean distance between vec1 and vec2).

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Hey, So I am feeling much better with ofPolyLine() instead of drawing each segment with ofLine()!

Reason why I used different seed for each iteration was to give a different noise shape (but same amplitude and freq) for each line that I am creating.

Basically, I am trying to create bunch of lines that has same start and end points but along the way points are behaving differently with Perlin noise with different seed like lightening.

@fkkcloud you could also use a different approach. You can look at the noise1dOctaveExample using ofVertex() between ofBeginShape() and ofEndShape().

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