Draw points along curve

andyjw86

in Contributed Library Questions • 1 year ago

Hi all,

Very new to processing. There is a similar discussion about 2 years back about this topic, but no conclusions were drawn on the thread, just recommendations. I am using the Igeo library because I am working between rhino and processing. What I would like to do is generate a random series of points around a curve within a certain distance from that curve. So far I have drawn all the points as well as a curve based on those points, but I can't figure out how to generate a random series of points along the curve. Below is what I have. Any help would be great, I am exhausted from trying to figure this out. Thanks!

import processing.opengl.*;

import igeo.*;

ICurve[] crvs;

void setup(){

size (700,700,IG.GL);

background (0);

ICurve[] crvs = IG.curves(); //getting curves

println(crvs.length);

}

void draw (){

new IPoint (519.72,519.72,-38.27);

new IPoint (519.72,467.75,-19.65);

new IPoint (519.72,415.77,-100.41);

new IPoint (519.72,363.80,46.96);

new IPoint (519.72,311.83,4.88);

new IPoint (519.72,259.86,-54.64);

new IPoint (519.72,207.89,-89.28);

new IPoint (519.72,155.92,47.65);

new IPoint (519.72,103.94,-2.08);

new IPoint (519.72,51.97,60.85);

new IPoint (519.72,0.00,44.26);

double[][] controlPoints5 =

{{519.72,519.72,-38.27}, {519.72,467.75,-19.65}, {519.72,415.77,-100.41}, {519.72,363.80,46.96}, {519.72,311.83,4.88},

{519.72,259.86,-54.64}, {519.72,207.89,-89.28}, {519.72,155.92,47.65}, {519.72,103.94,-2.08}, {519.72,51.97,60.85},

{519.72,51.97,60.85}, {519.72,0.00,44.26}};

new ICurve(controlPoints5,3).clr(1.,0,1.);

Replies(4)

cedrickie..

Re: Draw points along curve

1 year ago

i didnt really check your code but for drawing points along a curve there is http://www.processing.org/reference/bezierPoint_.html

PhiLho

Re: Draw points along curve

1 year ago

As Cedric said. Check if your library offers a similar capability. Then you can take these points and compute a small random offset from them for new points.

andyjw86

Re: Draw points along curve

1 year ago

Appreciate the responses. That's definitely what I want to do. Just don't know how to go about it since I just started using Processing. I have the curve drawn but I can't figure out how to extract the new point data of that curve. Sifting through I Geo's library is helpful, but hard to understand. Here is what is written about extracting points. Link

               
                /** start point of the curve */
               
               
                    
                synchronized 
                public 
                IVec 
                start
                (){ 
                return 
                curve
                .
                start
                (); 
                }
               
               
                    
                /** end point of the curve */
               
               
                    
                synchronized 
                public 
                IVec 
                end
                (){ 
                return 
                curve
                .
                end
                (); 
                }
               
               
                    
                /** start control point of the curve */
               
               
                    
                synchronized 
                public 
                IVec 
                startCP
                (){ 
                return 
                curve
                .
                startCP
                (); 
                }
               
               
                    
                /** end control point of the curve */
               
               
                    
                synchronized 
                public 
                IVec 
                endCP
                (){ 
                return 
                curve
                .
                endCP
                (); 
                }
               
               
                

               
               
                But the syntax doesn't quite work the way it is.  Anyone know how to input this 
               
               
                into my script above to get the new points?

andyjw86

Re: Draw points along curve

1 year ago

Whoops. There is also this.

               
                /** getting i-th control point */
               
               
                    
                synchronized 
                public 
                IVec 
                cp
                (
                int 
                i
                ){ 
                return 
                curve
                .
                cp
                (
                i
                ).
                get
                (); 
                }
               
               
                    
                /** getting i-th control point */
               
               
                    
                synchronized 
                public 
                IVecI 
                cp
                (
                IIntegerI 
                i
                ){ 
                return 
                curve
                .
                cp
                (
                i
                ); 
                }
               
               
                    
               
               
                    
                synchronized 
                public 
                IVecI
                [] 
                cps
                (){ 
                return 
                curve
                .
                cps
                (); 
                }

Top Reply