Is this stupid?

x1 = a t^3 + b t^2 + c t + d
y1 = e t^3 + f t^2 + g t + h
x2 = i t + j
y2 = k t + l

Find all intervals of t such that 3d distance between (x1, y1, t) and (x2, y2, t) < n.

Basically I want to do continuous circle-circle collision detection, which with linear motion would be a simple capsule-capsule intersection, but one of the circles has non-linear motion.  Is this feasible or should I just give up now?

Well, it's just a polynomial... But once you square it, you get a degree of six, and there's no general solution for degree five or higher.

1l1l1l1l1l1l1l1l1

Just curious, why bother with 3d and not 2d distance? ..err why is the problem worded that way?

>>1
The equation you have to solve is going to be a sixth degree polynomial, which has no solution with an easy formula.  You could solve it iteratively inside your program, but that might be too slow.

>>1
You'd have to use screen recording software such as Cam Studio. You do need a relatively beefy PC, because they can cause major lagging.
 
For mine I use Mame++ and it's "record to avi" feature, because it's lag-free.

screen recording software

0/10