Posts tagged with '3D print'

Voxel Volumes

  • Posted on November 28, 2014 at 8:37 pm

One of the main feature additions of the latests version of Functy has been the ability to export as SVX files. Functy could already export in PLY and STL, but both of these are triangle based. They represent the 3D functions as surfaces defined by carefully aligned triangle meshes. Rendering objects using a graphics card also uses the same triangulation process, so exporting as PLY or STL is a very natural extension of the existing rendering.
The SVX format is different though. It stores the models as a voxel image (a voxel being a three dimensional pixel, for those who didn’t grow up through the 90s demo scene). As a result, SVX doesn’t just store the surface, but also the volume of a function.
Turning a triangulated surface into a voxelated volume isn’t necessarily straightforward, but Functy has the advantage of having all its objects originate as purely mathematical forms. In theory, this means voxel rendering them as volumes should be quite easily.
What I found in practice is that for Cartesian functions and spherical functions this is true: they can be turned into voxel volumes in a very natural way. Curve functions are a different story though. In the next few posts I’ll go through each of the processes separately, to give an idea about how the solutions for each of the three function types were coded.

Voxel posts

  1. Intro (this post)
  2. Cartesian Functions
  3. Spherical Functions
  4. Curve functions

Projections

  • Posted on July 30, 2013 at 6:10 pm

The sun was out in Liverpool today, creating crisp and long evening shadows. So it seemed like a great opportunity to take photos of recent 3D printed Functy objects. The full images are rather large, but show the grain of the printing, which I think is rather interesting in itself. Click on the images for the full views.

The original Lissajous is up on deviantArt and Shapeways; the alien egg is also on deviantArt and Shapeways.

Comparing renders with reality

  • Posted on July 27, 2013 at 11:33 pm

Shapeways delivered a new batch of 3D prints recently. I was particularly pleased with the Alien Egg print of a spherical function with the formula:

radius = (3*(0.5+(sin(cos(a)+(p*((3+cos((pi*0.3)-1.5))/4))*10)**2)+((6/6.6)*((2+sin(8*a))/3)**4)))*sin(p)+(4.3*(1-(sin(p)**2))),

colour (R, G, B) = (r/8, (3+sin((a)*8))/5, (3+cos(a*8))/5).

The print is actually rather small (just 6 cm diameter) and the ridges of the shape are really quite delicate. In spite of this, the 3D print has come out really very similar to the original design. I guess you might expect it to be pretty similar, given the way it was produced directly from the model! However, if you look really closely at the original you can see the strata through the object created by the printing process. What I’m really impressed with, though, is the colour produced. I’d expected this to be a bit washed out, but in practice it’s a pretty impressive match.

Below is a comparison of (from top to bottom) the Functy render, the 3D print and a render done using Blender Cycles. In case you’re interested and your browser supports APNGs, there’s also a peculiar animated version!

Alien Egg Comparison (Functy, 3D print, Blender; click to enlarge)

Alien Egg Comparison: Functy, 3D print, Blender (click to enlarge)

3D printed Functy rings

  • Posted on August 9, 2012 at 8:00 am

A parcel arrived from Shapeways recently containing some of the 3D printed ring prototypes I generated using Functy. The models were exported directly from Functy and converted into STY format before being directly uploaded to Shapeways for printing. All based on sine/cosine curves, there’s a flat version, a slightly bulging version and an irregular version. Since Shapeways did such a brilliant job printing the prototypes, the next step is to get them to print them in silver. Click on the links if you fancy having your own printed!

The Functy function files for all of these rings are up in the repository and will be included as example files in the next full release.

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