Anyone have any questions about fractals?

Discussion in 'General Discussion' started by shawn_halayka, Apr 17, 2015.

  1. shawn_halayka
    shawn_halayka Well-Known Member
    Hello,

    I am wondering if I can be of assistance to anyone that might have questions about fractals? I'm not quite an expert, but I do have about 10 years of experience playing around with them. Right now I'm focusing on quaternion-based fractals. I haven't had much experience with Mandelbulbs, but I'm always willing to learn.

    I got my first print in the mail today (see attached image); it's a quaternion-based fractal printed out into plastic.

    image.jpeg

    - Shawn

     
  2. UniverseBecoming
    UniverseBecoming Well-Known Member
    Nice. :D

    Know of any software that is good for creating 3D fractals? How did you create this 3D model?
     
  3. shawn_halayka
    shawn_halayka Well-Known Member
    Thanks for the compliment. :) The fractals that I work with are called quaternion Julia sets.

    QuasZ is a GUI fractal generator that supports export to 3D file formats (ie. OBJ, STL) . It's $30 --> https://www.mysticfractal.com/QuaSZ.html

    Julia 4D 2 is a GUI fractal generator that supports export to OBJ. I wrote it about 10 years ago and it's cost-free and in the public domain. You may need to download a DirectX 9.0c runtime to run this app --> https://github.com/AnthonyNystrom/Julia-4D I've included a compiled version in a zip file attachment to this post.

    I also wrote my own commandline fractal generator from scratch. It's cost-free and in the public domain and supports export to STL format. It's also GPU-accelerated, so it's much faster than the two other apps listed above --> https://code.google.com/p/qjs-isosurface/ I've included a compiled version in a zip file attachment to this post. You will need to download the GLUT and GLEW libraries to run this app.

    I generated the model using my commandline software. The iterative equation that I used for this model is z' = sin(z) + c*sin(z). I use this equation to test which points along a 3D grid belong in the fractal set. Once those tests are complete, I use Marching Cubes to generate the final triangle mesh.

    A really good introduction to quaternion fractals can be found at: https://paulbourke.net/fractals/quatjulia/

    A really good introduction to Marching Cubes can be found at: https://paulbourke.net/geometry/polygonise/

    A really good introduction to quaternion math can be found at: https://www.theworld.com/~sweetser/quaternions/intro/tools/to ols.html

    If you're not into quaternions, a really good introduction to 2D fractals can be found at: https://www.codeproject.com/Articles/650821/Fractals-in-theor y-and-practice (see: Julia set).

    Hope that answers your questions. If you'd like more detail on a certain part of my explanation, then please feel free to ask. :)

    For the record, the model was printed using White Strong & Flexible plastic, and it's downright awesome to behold. Shapeways rocks!!!
     

    Attached Files:

    Last edited: Apr 19, 2015
  4. stop4stuff
    stop4stuff Well-Known Member
    Nice print!

    I bet it would look awesome with some colour and done in Full Colour Sandstone.

    I've been playing with Mandelbulb 3D (http://www.fractalforums.com/mandelbulb-3d/) recently - free software, with voxel stack capable output. I've not utilised the voxel output yet as I'm still learning the ropes with creating the actual 3D fractals.

    Paul
     
  5. shawn_halayka
    shawn_halayka Well-Known Member
    I'm working on an x3d exporter right now. My aim is to make fractals with per-vertex colouring, similar to the screenshot I've attached. :)

    puffball.png
     
  6. shawn_halayka
    shawn_halayka Well-Known Member
    Tada!

    I've attached the C++ source code that converts an STL file into a rainbow-coloured X3D file.

    puffball.png


     

    Attached Files:

    Last edited: Apr 21, 2015
  7. shawn_halayka
    shawn_halayka Well-Known Member
    I made another colouring scheme based on the vertex normal. It's included in the source code attached to my last post.

    sin.png
     
  8. shawn_halayka
    shawn_halayka Well-Known Member
    Perlin cow colouring. :)

    cow.png
     
  9. shawn_halayka
    shawn_halayka Well-Known Member

    Attached Files:

    Last edited: May 1, 2015