121–130 of 179 posts
Draw a horizontal line under the water, then return back to its start with a wavy line crossing over the first line repeatedly. Very strange things happen. The first time i tried, it leapt out of the water then flapped around..
This is a very obvious in retrospect flaw for anybody that has experience in graphic computing, but it's a common gotcha even there.
What a cool idea. Drawing a star is fun. If you draw something in the basic shape of a Y, with two thick arms and one thin arm, my instinct tells me that the two thick arms should end up on the top, with the thin one pointing down into the water. Is that accurate? There's not much jostling in the demo; any of the arms might end up pointing down. EDIT: You can also pretty easily get something to float in either an M o…
Earlier quoted context omitted.
> Do you have a notion of how the code actually computes bouyancy? Weight force (downward) is determined by the full polygon. Buyancy force (upward) is determined by the part below the water line. Lateral/angular motion results from the fact that the forces act on the centroids of the full polygon vs the centroid of the submerged polygon. The script seems to use a JS library named "turf" to clip the polygon at the wa…
Lol, thanks for the info. I was able to engineer an iceberg-boat. The boat is low mass but high bouyancy. If it were to be fully submerged, it would remain partially sunk. https://ibb.co/T1KG5DM
I get interesting results if I draw a figure 8 (or a figure ∞). I wonder if it's treating one of the lobes as having negative density.
Also, the code has been amended right where this comment is:
// People like to draw shapes with kinks, which results
// in part of the polygon being treated as negative area.
// turf.unkinkPolygon can be used to find the kinks and
// separate the polygon into multiple polygons at the
// kinks, but it's a little fragile and hard to combine
// into a single unkinked polygon. [...]I get interesting results if I draw a figure 8 (or a figure ∞). I wonder if it's treating one of the lobes as having negative density.
I think this was patched just now. On my last visit a few minutes ago the bug still worked, now it removes any larger bits where the lines intersect. Also, the code has been amended right where this comment is: // People like to draw shapes with kinks, which results // in part of the polygon being treated as negative area. // turf.unkinkPolygon can be used to find the kinks and // separate the polygon into multiple p…
> turf.unkinkPolygon=(x)=>x;
Press F12, click 'Console', copy-paste the above one and press Enter.
I get interesting results if I draw a figure 8 (or a figure ∞). I wonder if it's treating one of the lobes as having negative density.
I spent... longer than I should have trying to take advantage of this bug to recreate a stable version of the stereotypical tall iceberg that the original tweet was complaining about. https://imgur.com/a/WG6D0RJ
Any convex shape will tend to minimize the forces due to buoyancy and "horizontal" should always go less deep (or equal for a sphere) than "vertical"
Now every time I'll encounter one of those I'll feel mildly irritated. Sometimes ignorance is bliss.
So without any further knowledge about how icebergs should orient and how scientists draw them: Icebergs in 3D will generally have different mass distributions than the corresponding 2D projections that we are drawing here. For example, there will generally be higher "2D mass density" in the center. Consequently, it is possible that the scientists "drawing icebergs wrong" are actually right and it just looks/"behaves…
So the iceberg could very likely float like that when taking into considering 3d space + the random distribution of mass that is different in different parts of the iceberg.
Earlier quoted context omitted.
It’s interesting that proponents of a simpler web argue in favor of Jquery for a use case where jquery is in fact very easy to live without. One would almost think dogmatic thinking is involved.
> It’s interesting that proponents of a simpler web argue in favor of Jquery for a use case where jquery is in fact very easy to live without. One would almost think dogmatic thinking is involved. But to do without it, you will end up rewriting the shortcuts and utility functions that JQuery provides, effectively recreating a project-specific, less-tested and less-supported JQuery.
Otherwise I agree with you in general.