Re: Fuzzy lines

[Henning Hraban Ramm <texml@fiee.net>]

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> Am 13.05.2021 um 19:17 schrieb Aditya Mahajan <adityam@umich.edu>:
> 
> On Thu, 13 May 2021, Henning Hraban Ramm wrote:
> 
>> 
>>> Am 13.05.2021 um 18:36 schrieb Aditya Mahajan <adityam@umich.edu>:
>>> 
>>>> Now I want to draw that path several times.
>>>> 
>>>> If I understand it right, I can’t put that into "sketchdraw" because that leaves the end open for path additions like "withcolor".
>>> 
>>> A slightly different approach is needed. See attached. I also added a bit a error protection in case someone sets sketch_passes to be negative by mistake. 
>> 
>> Thank you so much!
> 
> Here is a different effect ... more of a trembling hand drawing than a sketch. You can play around with sketch_amount to see some variation. 
> 
> In this, rather than using the default randomized path (which randomizes the points of a path), I split the path into 20 segments, and randomize each segment. 

Thank you, that is what I was asking for!

Unfortunately, the deviation of edge points is too big – try my attached test file.

Strangely, if I include the MP code in a ConTeXt document, the transparency doesn’t work (it multiplies, but at 100%); I must add "withtransparency ("multiply", 0.2)" to my draw command. I’ll try to come up with a MWE. (Transparency of an image also doesn’t work in that document.)

My test file also includes the noise overlay after Jairo’s suggestions. Maybe you want to implement that, too?
At the moment it still doesn’t respect the pen size, and the number of patterns per path is fixed.

Hraban



[-- Attachment #2: sketchtest.mp --]
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input mp-sketch;

beginfig(1)
  color darkblue ; darkblue := (40/255,67/255,117/255) ;
  color beige ; beige := (248/255,245/255,236/255) ;
  %pickup pensquare xyscaled 4bp rotated 30 ;

  % bleed box, paper shading
  fill (-3mm,-3mm)--(-3mm,300mm)--(213mm,300mm)--(213mm,-3mm)--cycle withcolor beige;

  pen pillpen ; pillpen := makepen ((-1.5bp,-0.5bp)--(1.5bp,-0.5bp)..(1.5bp,0.5bp)--(-1.5bp,0.5bp)..cycle) ;
  pickup pillpen xyscaled 3bp ;

  sketchypaths;
  sketch_amount := 5bp;
  sketch_passes := 5;
  sketch_segments := 5;

  path one ; one := (-3mm,249mm) -- (185mm,249mm) -- (185mm,300mm) ; % links-oben
  path two ; two := (25.5mm,-3mm) -- (25.5mm,130mm) -- (213mm,130mm) ; % unten-rechts

  draw one withcolor darkblue;
  draw two withcolor darkblue;

  picture NoisePattern;
  NoisePattern := image(
    pickup pencircle xyscaled 0.5bp;
    numeric pmax ; pmax := 7 ;
  	for i = 1 upto pmax:
  		for j = 1 upto pmax:
        draw (i - (pmax/2), j - (pmax/2)) withcolor darkblue withtransparency ("normal", (uniformdeviate 0.33));
  		endfor
  	endfor
  );

  def noisify(expr p) =
    for i = 0 step 1/100 until length p:
    	draw NoisePattern randomized 1 shifted point i of p ;
    endfor
  enddef;

  noisify(one);
  noisify(two);

  naturalizepaths; % Restore the value of draw and fill

  % draw crop box (paper size)
  pickup pencircle xyscaled 0.5bp;
  draw (0,0)--(0,297mm)--(210mm,297mm)--(210mm,0)--cycle withcolor magenta;

  % begingroup;
  % save Rnd; let Rnd = uniformdeviate;
  %
  % numeric u; u := 3mm;
  % picture PlumaToo;
  % PlumaToo := image(
  % 	for i = 1 upto pmax:
  % 		for j = 1 upto pmax:
  %       fill fullcircle shifted (i - (pmax/2), j - (pmax/2)); %try fulltriangle or another shape
  % 		endfor
  % 	endfor
  % );
  %
  % for i = 0 step 1/20 until length one:
  % 	draw image(
  % 	for x within PlumaToo:
  % 		fill pathpart x %Assuming our image only contains cyclic paths
  % 		scaled (1+Rnd 1)
  % 		shifted (1/2dir Rnd 360)
  % 		withcolor hsvtorgb(6round(Rnd 60),9/10,1) %Colors just because they look cute
  %     withtransparency ("normal", Rnd 1);
  % 	endfor
  % 	) rotated (90 + angle direction i of one)
  % 	shifted point i of one;
  % endfor
  % endgroup;


endfig

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