Moving and shrinking circle to a circle inside of it (PUBG like zone)

I am trying to create a battle royale circle gamemode within Arma3 that would work like in PUBG.

For anyone who doesn't know how it looks like:

Red circle should smoothly shrink into the blue one (that means sides that close to each other should move very slowly by adjusting speed of the red circle center)

Global variables:

Center = (getMarkerPos "marker_start"); // eg. [1000, 1000] ClosingSpeed = 0.5; CurrentRadius = 1000; EndingRadius = 250; Offset = 1; 

Code for generating new circle:

// Determines maximum radius of a new circle private _maxRadius = CurrentRadius * 0.7; // Generates radius of the new circle private _randomRadius = [_maxRadius * 0.6, _maxRadius] call BIS_fnc_randomNum; // Generates new circle center private _randomCenter = [CurrentRadius * 0.1, (CurrentRadius - _randomRadius)] call BIS_fnc_randomNum; // Randomizes position of the new circle within the old one FinalCenter = Center getPos [_randomCenter, random 360]; EndingRadius = _randomRadius; ClosingSpeed = ClosingSpeed / 2; // This number should be somehow calculated to make the closing circle animation work properly Offset = 0.75; 

Shrinking code, executed every 100 ms:

// Decreases radius CurrentRadius = CurrentRadius - ClosingSpeed; // Gets the angle between two center points - in degrees private _angle = ((FinalCenter select 1) - (Center select 1)) atan2 ((FinalCenter select 0) - (Center select 0)); if (CurrentRadius > EndingRadius) then { // This sets new position of the circle Center set [0, (Center select 0) + ((Offset * ClosingSpeed) * cos (_angle))]; Center set [1, (Center select 1) + ((Offset * ClosingSpeed) * sin (_angle))]; }; 

Without the correct Offset it shrinks like this - center points (red circle center was moving at a wrong velocity):