RE: [Algorithms] Bounding sphere of spheres

[Peter P. <pr...@ph...>]

>>> Direction = Delta*1/Distance; // normed Directionvector from P2 to P1
>>> Because of this divide this algorithm will actually fail if the two
spheres happen
>>> to have the same center. This is a case that needs to be tested
seperatelly.
>> actually, this case is already handled (if the two spheres have the same
>> center, the larger one will contain the other, and the divide won't get
>> executed)
>That's not true. Here is an excerpt of the code fragment to which I was
>replying:

Ooops, you're right, i was showing intermediate results for clearness and
thus broke the code :)

here's the corrected code:

Delta = P1-P2;
Distance = Delta.Length(); // where Length calculates the Length of a vector
if(r1>=r2+Distance) // sphere 2 contained in sphere 1
{
   P = P1; r = r1;
}
else if(r2>=r1+Distance) // sphere 1 contained in sphere 2
{
   P = P2; r = r2;
}
else
{
   Direction = Delta*1/Distance; // normed Directionvector from P2 to P1
   P = (P1+Direction*r1 + P2-Direction*r2)/2; // Position of Bounding Sphere
   r = (r1+r2+Distance)/2;
}