Fractal Tree Variation on TBgrabmp Done: Now working on OpenGL Version
lazarus / 39-Graphics

----------------------------------------------------------------------
Boleeman · 2024-10-03 07:55

Fractal Tree with Lines Variation on TBgrabmp


Variation in line thickness and colour.
Added randomness
Filter out branch sizes.
Save to opaque or transparent background.

Some nice trees can be made with this one.

Needed to reduce the attached png file sizes by reducing the size of
each picture.

Also found an interesting Javascript variation here:
https://www.johnpaulryan.com/blog/2016/09/20/Fun-with-Fractal-Trees
Source:
https://www.johnpaulryan.com/documents/tree.txt
Rename that to index.html and open in a browser.

----------------------------------------------------------------------
Boleeman · 2024-10-03 07:59

Actually I would like to see an OpenGL version of this one (like the
attached png below), with rounded branches.

This is the Python Script that makes such a tree (fromm
https://trinket.io/glowscript/d6813f0f82)

Would be nice to make a Lazarus OpenGL version.

Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i  GlowScript
2.9 VPython #this is the tree functiondef tree(limblen,r,a):  #theta
is the "bend angle" for each branching  theta=30*pi/180  #short is the
amount each branch decreases by  short=15 #this is the amount each
branch is decreased by  fract=.75  #repeat the branching until the
length is shorter than 5  if limblen>5:    #each branch is a cylinder 
  #a is a vector that points in the direction of the branch   
tcolor=vector(100,42,42).hat    if limblen<10:     
tcolor=color.green    cylinder(pos=r,axis=a*limblen,
radius=0.15*limblen,     color=tcolor, texture=textures.rough)    #r
is the position of the next branch    r=r+a*limblen    #rotate turns
the pointing direction    a=rotate(a, angle=theta,
axis=vector(0,0,1))    #here is the recursive magic   
tree(limblen*fract,r,a)    #now you have to go back to where you were 
  a=rotate(a,angle=-2*theta,axis=vector(0,0,1))    #this does the
otherside (also recursive)    tree(limblen*fract,r,a)   
a=rotate(a,angle=theta,axis=vector(0,0,1))    r=r-limblen*a     #this
starts the tree with the starting branchlength =
75startingbranch=75 #this is the location of the
basestartingposition=vector(0,-75,0) #this is the direction of the
first branch (up)startingdirection=vector(0,1,0)tree(startingbranch,st
artingposition, startingdirection)

----------------------------------------------------------------------
Boleeman · 2024-10-03 09:40

I had a go at converting the Python  version with cylinders for
branches to Lazarus OpenGL but I am not seeing the OpenGL fractal
Tree. Only scattered colours. What could be the fault ?

Perhaps the fault has to do with the projection I am using. I Don't
Know:

glMatrixMode(GL_PROJECTION);
glLoadIdentity;
gluPerspective(45.0, OpenGLControl1.Width / OpenGLControl1.Height,
0.1, 500.0);