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Showing posts from June, 2009

Growth and L-Systems

Have been reading about l-systems, mostly papers from here. Trying to get segment growth working as described in the growth functions section (1.9) of The Algorithmic Beauty of Plants. I don't understand a lot of it but I think I got the basic idea :D.It was really confusing after a certain point when reading about l-systems, they started making a lot more sense when I actually started trying to implement stuff!

The important part is that F is getting rewritten. The g parameter is incremented each time to act as an age attribute, so g is the linear growth, and then length is set by using g in a funky smooth step type function thingy ((-2*g^3)+(3*g^2)) to get a kinda sigmoidal growth.

The b variable is used to control the speed of the growth.

The rest is just for controlling the branching so that the l-system came to some kind of end state. Like the m parameter in A(m) which decays over generations so that it stops getting replaced eventually.

The generation parameter is just set to $F…

Cloth self shadowing

This is why Houdini is awesome, one node ignored and changed the bias on the ray SOP, and self shadowing just works :D

It probably needs a wind location specified so I can timeshift the occluding objects depending on the distance from the wind 'emitter'. meh.

hipnc is here