Hi....i m quite new on processing, but i m using it for my architecture master and i love this prog....i have some problem in the script i m using.....it is based on particle system library...i m using different arrays to redistribute a series of node in space and rebalance theme according to attraction ad repulsion forces. Some of the arrays are specified elemnt by elemnt but this is due to my project needs. I dep systemloy a first series of particles and let them distribute in space....then with keypressed function freeze tehir position and deply a second number of particles...new array....that react to the fixed one and redistribute in space....what i want to do is now to freeze the second deplyment as well...and call a new double array that take the last fixed position of all teh particles deployed and create around them a local deployment of particles floating around each single old particle...the last part doesn t work.....this is the script....hope to have some feedback and i apologise for teh rudimental redondancy of the scripting technique..thx..code is following