Fractal models

Fracton

Fracton

0
Messages
22
Fractal models

I would like to announce Fracton, a free Mac only application for generating high quality fractal models that are compatible with C3D. Fracton generates height field models that look a bit like terrain. Here is an image of a model generated by Fracton and rendered in C3D.

castle_3d.jpg


Here is a link to a 20 second 10.8 Mb C3D animation that flies through the model.

http://dl.dropbox.com/u/33642054/image/castle_360p.mov

To get more information and download a free copy of Fracton, go to:

http://www.fracton.org/
 
Fracton's model methodology

I took a different approach on exporting models from Fracton. It exports an OBJ file of an optimal model using the least triangles it can. I wanted to have something so accurate you could move right up to the model and still have it look good. If you export height values in a grid even in 16 bit you get something like this:

comp2_grid.jpg


Sure, you can increase the resolution of the grid but still when you get close you will still see the jaggies. What I did in Fracton was make polygons out of contour lines that are fit to the fractal iteration bands, not to a grid. That looks much better. More like this:

fracton_method.jpg


Fracton calculates more points along the edge of the polygon when the edge is curvy and less when it is straight. In this screenshot from C3D you can see the model has more points in the curvy parts and less where it is straight:

adaptive_resolution.jpg


That makes the model much smaller. There is actually a lot more involved with the process than I mentioned here. I should also say that it is hard to get a perfect model and the process usually involves a compromise with how long you are willing to wait and how big a model you are willing to accept.
Thanks for the comments.
 
Thanks for the explanation - I investigate the output already. :p
Can you upload an 16bit highres image?

Thanks.

Cheers
Frank
 
Castle model

If you would like to experiment with the castle 3D model in C3D, you can download it (19.2 Mb file) from:

castlemodeltexture.zip

Double click the castlemodeltexture.zip file to decompress it. You will get a folder with a .OBJ and a .TIFF file in it.

Open Cheetah 3D. Select File -> Import... and open the pr_1-1_B.obj file. It is a big file and will take 30 seconds or more to load. Create a default material by clicking Add material -> Material. In the properties editor click on the white square at the far right side of the first line (the first line should say Diffuse). Choose Textures -> Image from the popup menu. Click the Load button in the Texture placeholder. Open the pr_1-1_BTex.tiff file. Drag the Material icon in the material editor to the line with the NOName object in the Object Browser.

I copied the Cheetah instructions from my tutorial documentation so it is probably too verbose for this audience.

A second way to get the model is to make it yourself. Download Fracton from:

www.fracton.org

Get the actual fractal parameter file from:

http://www.fracton.org/fmlposts/castle.html

>> frank beckmann asks: Can you upload a 16 bit highres image?

Do you want the raw 2D fractal data as well? I will go make that and include it in the next post.

Mike Frazier
www.fracton.org
 
Highres image files

>> frank beckmann asks: Can you upload a 16 bit highres image?

Here are two hi-res (2K x 2K) 2D image files of the castle fractal that should do what you want. Note that I don't recommend this method for making high quality models. The castle_bw.tiff has the height information and the castle_color.tiff is the normal color fractal image that could be used as a texture. The castle_bw.tiff image is an 8 bit/color greyscale image but with this particular fractal it would give exactly the same result as a 16 bit image. The height of this particular fractal ranges from a low of 23 units (the yellow areas) up to 130 (the red colors). Since this range of numbers fits exactly within 8 bits there is no loss or roundoff by using 8 bit greyscale information for the height.

castle_bw.tiff

castle_color.tiff

Mike Frazier
www.fracton.org
 
Up close

This image of a 3D model from Fracton, shows you can zoom in close and still have good quality. I also made a Quicktime animation (10 sec, 9.6 Mb) that flies down the valley. The image and animation were rendered in C3D.

terraces_of_fire_3d.jpg


It took Fracton 57 hours to make the model on my 2 core PowerPC Mac Pro. The animation took about an hour to render in C3D on my 8 core Intel Mac Pro. The original fractal is by Jim Muth and is from his Fractal Of The Day series. Jim's web page of the fractal is here.

Mike Frazier
www.fracton.org
 
You must log in or register to reply here.
Back
Top