Spring Constraint for Leaves or Multiple Object

 While the time working about Environment modeling we have discovered new way to give wind or noise to leaves using rigid body dynamix. It is pretty fast and also useful method becasue of working with any kind of force in Dop Network. This system can effect from pyro or flip fluid and also if you give too much power to your force/wind, your leaves will be tearing from the constraint and will fly in the air with your force.

This is workflow of the setup. Pretty easy and fast actually. 

- I had an setup for Tree or Bush creating which i posted that blog before lol you can create your tree on procedural way with l-system or you can use the tree from speed tree or polygon modelled mesh and so. Bush imput is only points for leaves , leaf input is my leaf that i modeled in Houdini also. Coppied them to points and packed them , then deleted all geometry but points. Gave them an id and used that points for my constraints.

First input for Leaves and the second imput is for my constraint points that i will use in the DOP Network. You can see the DOP Setup inside of it

First i have used rbdpackedobject node to get all packed leaves. Pop speed limit is for limiting the maximum speed , so i limited it for 5 because of it was ok for my scene. There are two different force so there is popwrangle force @torque = curlnoise(@P+@Time*2)*200; that creates torque inside the DOP which works like popwind or fanforce and the second force is popwind. I just put two of them to show there are different kind of force that we can use and also we can use any kind of force with multisolver.

There are two springconrel. One is controling the poisition and the other one controling the root group that i have created out of the DOP. I have it VEX codes too. and constraint network connect them to my setup. First input of the constraint network feeding by the rbdsolver and second input feeling by the springconrels , so i changed SOP Path of constraint Network as a 1 input (which houdini starts from 0) this way SOP Path taking data from my pos and rot data that i have created out of the DOP