Hi Richard, Sorry for the delay. It was a wonderful trip - the Caucasus mountains are glorious at any time of the year, and I have a lot of friends there in Svaneti. 6. If..Then programming for L-systems: I've not read or seen any examples of this, I just know that it's possible. My ideas concern the variables built into the language, such as Angle, @ (controlling length ratios of line segments), ! (reverse direction), brackets for stacking, etc. An example of If... Then would be the equivalent of "If f is at an angle of n degrees [from baseline, which is horizontal], do A", A being a new L-system string of the user's choice specified in the current L-system. One could have this new string kicking in if: f reaches size n as a ratio of the initial f; the total number of fs in the iteration reaches n; f reaches angle n in relation to baseline (as above); there are n copies of f "stacked" in layers directly on top of each other in the iteration; any of the above for g instead of f; the length or height of the entire iteration reaches n as a ratio of the initial f... These are a few possibilties I've thought of; there may well be many others. 7. I'm not at all familiar with P.P.'s 3d extensions; I have written to him about my infinite tile finds at least twice and received no answer. I revere his work, though, and have a copy of his first L-systems book. (It's not yet come out of storage along with most of my possessions which I tucked away when I left Georgia for Canada in 2005.) 3d L-systems - should these still be line-based, or somehow planar, or tube-based, or what? I don't know and haven't seen any of whatever 3d LS programmes might be out there. Sorry, I can't provide too much thought about this one. Tony Hanmer On 5/24/07, Richard <legalize@xmission.com> wrote:
Tony,
Now that you are back from your trip (I hope it was fun and relaxing), can you elaborate on these points you mentioned earlier?
In article <546ce4c30705012157g171b82f1q2992120db09e8a39@mail.gmail.com , "Tony Hanmer" <a.hanmer@gmail.com> writes:
4. Removal of some limitations (I've mentioned this before; not the highes t priority, but not too difficult to implement either I think, once Fractint migrates from DOS). Namely, *.l file limit of 2000 entries (Hanmer Tiles are infinite in number...), and L-system programming string limit of 256 characters (I think that's the current limit) (Hanmer Tile programming can lead to very long strings).
This can be done for the next beta.
6. IF-THEN programming. There are all sorts of possibilities for this, most of which I probably am not informed enough to imagine. Again, they would greatly extend L-systems programming.
Can you provide some sort of specification of how this would affect the L-system grammar? I have seen probabilistic L-systems and other extensions of continuous parameters into L-systems done by Przemyslaw Prusinkiewicz in his SIGGRAPH papers and books, but I don't recall him introducing a conditional extension.
7. 3d is perhaps not more than a dream or a distant goal, if anything.
Do you mean 3D a la P.P.'s extensions? Can you elaborate on this a little more?