This problem has been doing my head in and even my Houdini tutors.

I've created an L-system tree. And I am going for the “weeping willow” tree affect. So I have also created a long stem that has a slight curve with leaves attached, also using an L-system.

Now attaching the stem L-system to the tree; multiple times of course for the foliage. The problem is getting the stem onto the tree where each stem curves outward the way a weeping willow's foliage looks. I've messed around with plugging the the stem into the leaf inputs on the Lsystem SOP. And also I've Grouped the points on the skeleton of the tree where I would want the stem copied to. Of course these both work getting the stems onto the tree BUT the problem still remains getting them to taper off the way a weeping will does. This is tough because in the beggining there is only one stem, which is basically copied onto points.

Let me know if this isn't clear enough, it is tough to explain. And the greatest appreciation and amazement goes out to who can help. Thanks so much for your time!
Cheers!

Hey,

Well just an idea off the top of my head. You could use SOP POP to deform the geomertry of the L-System after you have created it and have it emit a particle per point only once on inital birth and then add gravity to the particles and it should droop. Then you could add wind and trubluence to make the branches automatically animate as a non-linear system. You could even randomize the particle weights based on the particle ID so that you get a more realistic simulation. The other idea that comes to mind is to put a lattice on the branches and pull them down. Mind you I have not tested these ideas because I have not had a chance too.

Cheers,
Nate Nesler

Thanks MatrixNAN, I will get that a shot soon!!!