Lucas P
Registered: 09-2005
Location: Canuckistan
Posts: 4167
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PIxel Circle Calculation
Hey guys,
As many of you know, MSPaint is not the best at drawing symmetrical or even consistent circles or curves. As a result of reviewing some of my older work, like R2's dome, I found that I was originally working on an angle gauge, but it had a specific purpose of measuring a line on a curved surface. What I realized is that using an angle gauge, I can generate any curve using pythagoras. I am currently working on a spreadsheet reference as well as a clip and pasteable image using a coordinate system.
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"Consider how stupid the average person is. Now remember that half of them are even stupider than that." - - George Carlin
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12/10/2019, 7:25 am
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Lucas P
Registered: 09-2005
Location: Canuckistan
Posts: 4167
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Re: PIxel Circle Calculation
here's a preliminary test of the gauge.
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"Consider how stupid the average person is. Now remember that half of them are even stupider than that." - - George Carlin
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12/10/2019, 7:54 am
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Lucas P
Registered: 09-2005
Location: Canuckistan
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Re: PIxel Circle Calculation
Here is a better version of the angle gauge. it is complete and accurate. I wrote the descriptor on the image.
Uses:
You can determine the angle of a line to within 1 degree.
The length of the lines in the drawing are 114 pixels (using pythagoras), therefore you can plot a circle or elipse with this.
I hope you find it useful (I know I will).
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"Consider how stupid the average person is. Now remember that half of them are even stupider than that." - - George Carlin
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12/30/2019, 4:56 pm
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Slay1
Registered: 11-2005
Posts: 595
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Re: PIxel Circle Calculation
It looks great. How do you use it?
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12/30/2019, 9:30 pm
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Lucas P
Registered: 09-2005
Location: Canuckistan
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Re: PIxel Circle Calculation
Great question.
okay, basically this sheet has two features;
One: it can measure the angle of a line. If you superimpose it as a transparency on top of your drawing. Remember, that for angles between 46 to 359, the sheet can be rotated in increments of 90 degrees.
Two: It can plot a circle or ellipse.
Let's say that you want to plot a circle of a certain radius, and you want to make sure that each of the plotted points are an equal distance apart to make a perfect circle. I don't recommend that you plot a point for each degree. it's best to use increments and then connect each point with a line. A version of this is how vector drawings draw with vertices (using an algorithm).
So, let's say you plot a pixel every 5 degrees along a radial line from the centre at 114 pixels, so you would superimpose from the sheet above squares in sequence from 5, 10, 15, 20, 25, 30, 35, 40, 45. then connect the dots.
Now that you have a quarter arc, you can clip it, rotate 90 degrees, paste. clip again and mirror 180 degrees and voila! a perfect circle.
This will also assist in making sloped curves using a second axis and connecting those plots for a more complex shape.
I hope this makes sense. I am considering a visual tutorial to assist with this technique, but I'm working on the gallery layout.
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"Consider how stupid the average person is. Now remember that half of them are even stupider than that." - - George Carlin
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12/30/2019, 11:22 pm
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Lucas P
Registered: 09-2005
Location: Canuckistan
Posts: 4167
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Re: PIxel Circle Calculation
Here's what a completed circle looks like with 5 degree increment plotted points flipped and rotated.
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"Consider how stupid the average person is. Now remember that half of them are even stupider than that." - - George Carlin
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12/31/2019, 1:25 am
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Kal Argos
Registered: 09-2014
Location: Outside Boston, MA
Posts: 431
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Re: PIxel Circle Calculation
Mr Spock,
What do the sensors pick up?... ... every time I draw one of those things I think of that moire pattern...
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12/31/2019, 11:14 am
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Slay1
Registered: 11-2005
Posts: 595
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Re: PIxel Circle Calculation
Thanks Lucas.
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12/31/2019, 5:58 pm
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