Nov
12
2012

Marching Tetrahedrons

An article by mgear

Tried to convert this marching tetrahedrons (by Mikola Lysenko) to Unity Javascript.. but its not working yet (^ that should be a sphere..)

Source (bugged, see the original source above and try to fix this?..Oo )

** See comments section for fixed version

//#pragma strict
import System.Collections.Generic;

var res = new Array(3);
private var grid:float[] = new float[8];
private var cube_vertices = [
[0,0,0]
, [1,0,0]
, [1,1,0]
, [0,1,0]
, [0,0,1]
, [1,0,1]
, [1,1,1]
, [0,1,1] ];

private var x:int[] = new int[3];
private var vertices:List. = new List.();
private var faces:List. = new List.();

function Awake ()
{
x[0]=0;
x[1]=0;
x[2]=0;
}

function Start ()
{
var verts:Vector3[] = MarchingTetrahedra(makeVolume(),res);
var triangles : int[] = faces.ToArray();

for (var n=0;n 1e-6) {
t = g0 / t;
}
for(var i=0; i<3; ++i) { v[i] += p0[i] + t * (p1[i] - p0[i]); } vertices.Add(new Vector3(v[0],v[1],v[2])); return vertices.Count - 1; } function makeVolume() { var dims = [[-1.0, 1.0, 0.25], [-1.0, 1.0, 0.25], [-1.0, 1.0, 0.25]]; for(var i1=0; i1<3; ++i1) { res[i1] = 2 + Mathf.Ceil((dims[i1][1] - dims[i1][0]) / dims[i1][2]); } var volume = new Array(res[0] * res[1] * res[2]); var n:int = 0; var zz:float=dims[2][0]-dims[2][2]; for(var k=0; k

Tags: isosurface, Marching Tetrahedrons

About the Author:

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11 Comments + Add Comment

mgear 24/11/2012 at 11:13

Bugged source added.. place it to gameobject with MeshFilter & MeshRenderer.

Reply
mrz00m 23/12/2012 at 02:06

Fantastic Demonstration WebGl Thing there! the “naive surface nets” are AWESOME also.

here is a link to some great 3d shapes “Gyroids” which i didnt understand
http://k3dsurf.s4.bizhat.com/k3dsurf-ftopic119-15.html

awesome website as always!

Reply
doodyo 11/02/2013 at 14:02

hello,

I just copied this code into new scene, put it on a GameObject with mesh renderer, everything apparently runs all right but I can’t see any mesh at all. The scene is blank, the GameObject doesn’t present any mesh or texture. it’s strange!?

Reply
doodyo 11/02/2013 at 14:04

hey it’s okay, I had put mesh filter and no mesh renderer! Thanks!

Reply
predatflaps 11/02/2013 at 17:50

Hello!
I have made some progress- instead of calculating a sphere, I separately calculated XY and Z as a plane.
http://i50.tinypic.com/2z4l73m.jpg
[IMG]http://i50.tinypic.com/2z4l73m.jpg[/IMG]

The X-formulas seem to have calculated okay
The Y and Z seem to be bugged

Reply
predatflaps 11/02/2013 at 17:51

instead of xx+yy+zz-1 in the last line of code

I put x-1
y-1
z-1

Reply
Alia 27/07/2013 at 23:25

I had a little poke around and fixed a few triangles.

https://sites.google.com/site/aliadevlog/marching-tetrahedrons-for-unity3d-javascript

Reply
- mgear 01/08/2013 at 18:38
  
  Thanks!
  
  (didnt notice the download arrow button at first..its there at bottom right
  
  Reply
- Tester 18/12/2014 at 17:06
  
  Hi there,
  Iam a little bit late for this amazing party, just found your port of marching tetra. But I saw that you also have a screenshot of surface nets in unity, can you share it?
  Thanks a lot
  
  Reply
- jimmio 03/05/2017 at 05:51
  
  Yes, can you please share your surface nets implementation? It shouldn’t be too hard to write, though.. so if you’re unwilling to share, maybe I’ll write it and share it.
  
  Reply
antony 03/05/2017 at 16:28

There’s a JS implemenation of surface nets perhaps here: https://0fps.net/2012/07/12/smooth-voxel-terrain-part-2/ …. … https://github.com/mikolalysenko/mikolalysenko.github.com/blob/master/Isosurface/js/surfacenets.js github addy…
To voxelize an ISO, i know a bunch of methods… depends if you want to solid fill with cubes or put cubes on the iso border spaces. * SurfaceNets in JavaScript
*
* Written by Mikola Lysenko (C) 2012 if you run it in Unity please share your conversion!

Reply