So there's this thing I want to do, simulating self-assembly of a few 
dozen parts.  The idea is that each part has a small number of nodes 
that are attracted to corresponding nodes on other parts.

To find its proper place, a part will generally have to be both 
translated and rotated.  Translation is easy: for each node there's a 
vector to its mate, and the part moves on each step by some fraction 
(probably half) of the average of these vectors.

Rotation is where I'm stuck.  The obvious metaphor is torque: cross that 
node-to-node translation vector with the center-to-node vector, and you 
get a torque vector, and all the torque vectors for each part can be 
averaged together ...

But wait, I don't want to give the part some angular momentum, I want it 
to *step* by the needed rotation.  I want a function that translates 
(pardon the pun) the sum of these pseudo-torque vectors into a rotation 
matrix -- and I never did study 3D rotation matrices.

So, have you done anything similar?

-- 
*\\* Anton Sherwood *\\* www.bendwavy.org

Post a reply to this message