hi all..

I've tried prototyping wood grain as a series of grids stacked on each other, but handling knots is a problem. I tried using a sphere to represent a knot then using a Ray SOP to deform the grid with an offset.. but it wants to warp the entire grid around the sphere and i'm treating the grain as a series of planes which deform where they intersect the sphere's volume of influence. Does anyone know of a good way to handle this? Perhaps cloth.. but i suspect it would be slower and more complex.

thanks

Maybe vorticles exported from a dopfield could help. I used it once to make a piece of basalt.

Thanks.. fluid flow sounds like an interesting approach.

A knot is actually the core of a branch rather than a distortion of the surrounding grain and, after following up on your suggestion, i found a paper by PJ Pellicane that models wood using laminar fluid flow around an elliptical obstruction. This would work ok for my needs i think. Alternatively a simple 3D procedural function of the type commonly used for procedural textures might do, too. I think it would be quicker.

These don't fully simulate knot formation, though. Perhaps there is a way to do this with an l-system simulating the growth of a tree? Probably overkill :roll: .

I have read a paper on using l-systems to simulate knot growth, I think it was this one:

http://www.springerlink.com/content/b34q1031l8k3w850/ [springerlink.com]

I don't have access to spingerlink at the moment so I can't be sure, but I'm pretty sure thats the one.

Thanks.. it seems like it might be workable..