signed distance fences

[xibanya@mastodon.xyz]

signed distance fences

[xibanya@mastodon.xyz]

someone on tiktok replied "if it's a fence then it's not possible to be a negative distance away from it"

...i need u to

use ur imagination

ok?

[oblomov@sociale.network]

@Xibanya IME the concept is better approached in terms of level sets. Take a fancy mountain range, and with a pencil marker (or a fence) mark out a specific altitude a.s.l.. This way it shows how everything on one side of the fence is positive (higher than the fence level) and everything on the other side is negative (lower than the fence level).

1/3

[oblomov@sociale.network]

@Xibanya

Next one shows that different mountain ranges can have the same level set (marker line at specific altitudes) because the marker line itself does not care about what's on either side of the fence, as long as it never crosses the altitude in any other place than where the marker line is.

And then one gets to the “ideal” mountain range, where the slope is unit, so the amount you walk away from the fence matches how much you go above or below it.

2/3

[oblomov@sociale.network]

@Xibanya

And finally, the choice to make the mountain range slope upwards away from the enclosed space and downwards towards the inside is largely conventional, but it has this nice “private valley” imagery to it.

3/3

[oblomov@sociale.network]

@Xibanya

P.S. this is obviously not an explanation for you, just saying that this is the explanation I've found goes well with people who don't seem to have a natural intuition to it.