Signed Distance Function (genuary day 29)

Here I define two circles with a function that, given a coordinate pair, returns a positive distance from the shape outline for any point outside the circle, and a negative number for any point inside. The two results are multiplied together, giving something like the XOR of the two shapes. I then use rejection sampling (more likely to select points far away from the shape, and never inside) and for each selected point calculate the gradient using the Sobel operator by comparing against nearby points.

Black Rotring ink, 0.35mm line, on recycled white cartridge paper.
About 75x75mm each and taking up to 10 minutes to draw.

The video clip shows a few attempts at using different pens, but at this size the isograph worked best. The Bic pen I think needs longer lines before it draws properly and isn't suited to stippling, and the fountain pen lines were too thick and bled into each other too much, but might work at a larger size with more distance between the lines.

#signeddistancefunction #sdf #penplotter #penplotterart #genuary #genuary29 #genuary2024

4 months ago