Doom3world

Hi, first:

What is retopologizing?
When you sculpt anything from a low poly form to a "many subdiv" form, sometimes you finish with somthing far away from the begin's form.
So the low poly form topology is no more good, or some area are too much streched, or your UV are deformed, etc...
ReTopologizing is the action to rebuild the low poly form, moving each points/vertex, but keep the same high subdiv sculpt/form.
You can also directly import a new low poly form with the same number of vertices and applying higher subdivs on it. (that's what i'm trying to do)

Of course i read some tuto about the thing, but i can't achieve it right. there is always crazy deformations, nothing happen, or ZB just crash.

So, if one of you here know how to perform it right, could you explain me how to do it?

Thanks!