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                            * ARBRES.INC Help File *
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                            By J.L PRADEL alias Pidou


INTRODUCTION
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  I made this include file for POV-Ray 3.0 using the work of Joachim Puerschel.
I changed the runtime and added some parameters.
  If you want to join me : pidou@club-internet.fr
  You can use and distribute freely this file.
  Sorry to people who will use it but all parameters names are in French.


STRUCTURE OF THE CONSTRUCTION AND PARAMETERS
--------------------------------------------

  The tree is based on 3 branch levels. The number of branches in each level
is independent. Only the average angle between two levels is constant.
Branches from level 1 are linked to the trunc. Branches from level 2 are
linked to branches from level 1. And so on...
  The leaves are simple resized disks.

ALLURE : This parameter could take two values 1 or 2. The difference is made
         at level 2 and 3 where branches can not have a random position.
         The value 2 could help to make firs (I have not a lot of succes yet).
         DEFAULT VALUE = 1.

NB1, NB2, NB3 : These parameters give the number of branches at each level.
                DEFAULT VALUES NB1 = NB2 = NB3 = 6.

NB_FEUILLE : This is the number of leaves per branch.
             DEFAULT VALUE = 50.

TAILLE_FEUILLE : This parameter give the size of the leaves.
                 DEFAULT VALUE = 1.

ANGLE_MOYEN : This is the average angle between a branch of level "n" and
              a branch of level "n+1". In the calculation a random value is
              added or subtractd to this one.
              DEFAULT VALUE = 45.

ANGLE_ECART : Defines the random value added or substracted to ANGLE_MOYEN.
              The calculation is : angle_moyen+angle_ecart*(1/2-rand(Alea).
              DEFAULT VALUE = ANGLE_MOYEN/5.

ANGLE_FEUILLE : Defines the angle between the leaves and their branch.
                DEFAULT VALUE = ANGLE_MOYEN.

TAILLE : This is the size of the trunc. It defines the size of all the
         branches then of the tree. It has no effect on the size of the leaves.
         DEFAULT VALUE = 20.

REDUCTION : Defines the ratio between two branches of consecutive levels.
            This parameter is used directly in a SCALE command.
            DEFAULT VALUE = 2/3.

POSITION_MIN, POSITION_MAX : Define where the branches are linked to a
                             "mother" branch. The position of the branches is
                             randomly calculated between POSITION_MIN and
                             POSITION_MAX scaled by the size of the "mother"
                             branch.
                             DEFAULT VALUES POSITION_MIN = taille/3
                                            POSITION_MAX = 2*taille/3.

ALEA : Defines the seed of the random generator.
       DEFAULT VALUE = Seed(0).


CONCLUSION
----------
  Have fun, and do not hesitate to test strange values, the result could
  be unexpected. If you have any comment, question, ideas of improvements
  contact me to pidou@club-internet.fr