The computer-designed objects called trajectoids follow a predetermined path when rolling, and usually look somewhat like peeled potatoes.
I haven’t seen a trajectoid with an obviously arbitrary, complex path, such as someone’s signature (as opposed to demos of epicycles), so there may be limits to what lines can be made.
I think the similarly-looking gömböcs are cooler: convex, uniform objects that always return to one stable orientation when laid on a flat surface.
Not entirely irrelevant to D&D. Now we know that a skilled scholar could sculpt a boulder to roll in a specific way (for an Indiana Jones-style trap) without casting spells. Still, adjusting the terrain is a more productive way to do that.
But they're not useful as dice. Nobody ever uses a die’s trajectory shape to determine a random in-game outcome.
A gömböc could technically count as the most rigged die – only ever rolling up one number – if the only requirements for a D&D die were for it to be a convex object with uniform density.
TL;DR They’re not dice.
The computer-designed objects called trajectoids follow a predetermined path when rolling, and usually look somewhat like peeled potatoes.

I haven’t seen a trajectoid with an obviously arbitrary, complex path, such as someone’s signature (as opposed to demos of epicycles), so there may be limits to what lines can be made.
I think the similarly-looking gömböcs are cooler: convex, uniform objects that always return to one stable orientation when laid on a flat surface.

Very cool from a maths perspective, but irrelevant to D&D
Not entirely irrelevant to D&D. Now we know that a skilled scholar could sculpt a boulder to roll in a specific way (for an Indiana Jones-style trap) without casting spells. Still, adjusting the terrain is a more productive way to do that.
But they're not useful as dice. Nobody ever uses a die’s trajectory shape to determine a random in-game outcome.
A gömböc could technically count as the most rigged die – only ever rolling up one number – if the only requirements for a D&D die were for it to be a convex object with uniform density.
Plato: "A die is a convex object with uniform density."
Diogenes: holds up gömböc "behold: a die!"
(Diogenes is genius but poor so the gömböc is a peeled potato)
Now seriously, the convexity requirement is there to ensure that spheres with voids inside don't qualify.
Its a d1, aka DM says so.
As a DM, that's my favourite die to roll. Well, other than the rocks-fall-you-die
trajectoids video