Quick L-system Question

[kai.scorpio]

The l-system help describes two methods for "edge rewriting"...

Premise F(1,1,3,3,0)

Rule 1 F(i,j,k,l,m) :m=0 = F(i,j,k,l,0)+F(i,j,k,l,1)+

Rule 2 F(i,j,k,l,m) :m=1 =-F(i,j,k,l,0)-F(i,j,k,l,1)

Which gives a nice transition between generations, but is quite long to write out, and:

b ch("generations")

Premise l

Rule 1 l:t<b=l+r+

Rule 2 r:t<b=-l-r

Rule 3 l=F

Rule 4 r=F

Which is much simpler to write out, but doesn't transition between generations, instead it shrinks towards the origin and then suddenly jumps to the next pattern... also I don't understand how the first part (l:t< works/what it means.

Is there a way to get the effect of the first method, but so it is simpler to write like in the second method? I'm new at l-systems so please keep it simple (if possible)

(EDIT) I skimmed a bit further through "algorithmic beauty of plants" and it seems like edge rewriting is abandoned for a while...

Edited September 20, 2007 by kai.scorpio

[ranxerox]

I have the exact same question (I suspected that someone else might have asked it). I'm sad to see there were no replies. I can answer that the code t<b tests the current generation against the final generation, I assume so that the rule will not match on the final generation. I too would like to use the simpler syntax, as suggested in the help, but unfortunately it does not seem to work.

anybody ?

thanks

-ranxx

The l-system help describes two methods for "edge rewriting"...

Premise F(1,1,3,3,0)

Rule 1 F(i,j,k,l,m) :m=0 = F(i,j,k,l,0)+F(i,j,k,l,1)+

Rule 2 F(i,j,k,l,m) :m=1 =-F(i,j,k,l,0)-F(i,j,k,l,1)

Which gives a nice transition between generations, but is quite long to write out, and:

b ch("generations")

Premise l

Rule 1 l:t<b=l+r+

Rule 2 r:t<b=-l-r

Rule 3 l=F

Rule 4 r=F

Which is much simpler to write out, but doesn't transition between generations, instead it shrinks towards the origin and then suddenly jumps to the next pattern... also I don't understand how the first part (l:t< works/what it means.

Is there a way to get the effect of the first method, but so it is simpler to write like in the second method? I'm new at l-systems so please keep it simple (if possible)

(EDIT) I skimmed a bit further through "algorithmic beauty of plants" and it seems like edge rewriting is abandoned for a while...

[Ezz]

Hi folks.

I just copy/pasted this from the help section:

F(l,w,s,d) Move forward (creating geometry) distance l of width w using s cross sections of d divisions each.

The example is:

Premise F(1,1,3,3,0)

Rule 1 F(i,j,k,l,m) :m=0 = F(i,j,k,l,0)+F(i,j,k,l,1)+

Rule 2 F(i,j,k,l,m) :m=1 =-F(i,j,k,l,0)-F(i,j,k,l,1)

m is a variable introduced to set conditions with

Erik

Edited November 16, 2008 by Ezz

[ranxerox]

yes, this works, but it is ugly, and doesn't look like the code from the book. The question is why doesn't the second formulation in the help work.

-ranxx

Hi folks.

I just copy/pasted this from the help section:

F(l,w,s,d) Move forward (creating geometry) distance l of width w using s cross sections of d divisions each.

The example is:

Premise F(1,1,3,3,0)

Rule 1 F(i,j,k,l,m) :m=0 = F(i,j,k,l,0)+F(i,j,k,l,1)+

Rule 2 F(i,j,k,l,m) :m=1 =-F(i,j,k,l,0)-F(i,j,k,l,1)

m is a variable introduced to set conditions with

Erik