The tsp drawing starts with a stipple, which is a pattern of dots where the density of the dots is related to the darkness of the image in an area. Then draw a tsp path through them all. Done.
The triangle fill and circle pattern seems similar where instead of a tsp path you triangulate, for example by Delauney triangulation. For the circle pattern you would place circle size and density depending on image darkness, or maybe you could just do stipple first and then convert to circles according to the distance to the nearest other dot.
For lines like the ‘spiral’ or ‘paper cutout’ of that kickstarter, thats a pretty similar to a traditional halftone where the width of the line is proportional to the image darkness.
Of course thats just the algorithm, actually acquiring the software to do it is a different matter.
One other option I’ll throw in there is ASCII art.