Voxel to 3D render?

[twinbee]

Two simple questions really:

1: Which 3D rendering program (preferably a raytracer), renders 3 dimensional voxel data I have created externally (perhaps from a text file) ? At minimum, it would be converting 2 color data (i.e. the voxel either exists or it doesn't), but preferably, also optionally taking into account the 'colour' of the voxel.

2: Even more advanced, is there a 3d program which 'looks' for surfaces in the 3D voxel data, and converts these to surface polygons (or for programs like povray, mathematical curves). It would be the equivalent of a 2D structured drawing program tracing the outline of a shape in a bitmap picture. Once again, I'm thinking of the 3D program being able to read my external data, such as ascii data created from a C program. I'm hoping for something a little more advanced than the marching squares (or cubes) algorithm which only allows for 45 degree jumps of lines or polygons.

[David Makin]

I'm no expert but I have a vague recollection that you may need to convert your voxel data into "wavefront" format (whatever that is !)

[lycium]

1: Which 3D rendering program (preferably a raytracer), renders 3 dimensional voxel data I have created externally (perhaps from a text file) ? At minimum, it would be converting 2 color data (i.e. the voxel either exists or it doesn't), but preferably, also optionally taking into account the 'colour' of the voxel.

another forum member, don casteel, started writing a program which does this (and voxelises 3d flame fractals) but i think he's given it up now that he's into working with sunflow (a really nice opensource java ray tracer).

certainly there are others (none spring to mind right now), and i plan to write my own volume rendering code soon; in fact, here's a preliminary render using homogeneous (constant/nonvarying) fog:

2: Even more advanced, is there a 3d program which 'looks' for surfaces in the 3D voxel data, and converts these to surface polygons (or for programs like povray, mathematical curves). It would be the equivalent of a 2D structured drawing program tracing the outline of a shape in a bitmap picture. Once again, I'm thinking of the 3D program being able to read my external data, such as ascii data created from a C program. I'm hoping for something a little more advanced than the marching squares (or cubes) algorithm which only allows for 45 degree jumps of lines or polygons.

the marching cubes algorithm is pretty much the standard method to do this; your best bet would be to modify such code to implement the angle constraints you want.

[doncasteel8587]

another forum member, don casteel, started writing a program which does this (and voxelises 3d flame fractals) but i think he's given it up now that he's into working with sunflow (a really nice opensource java ray tracer).

Actually, I haven't given up on it, my volumetric raytracer is still alive and in an ongoing work in progress.

Since Fractrace and Sunflow are both 100% Java, it only makes sense to merge the two. Sunflow is a more complete general raytracing platform, and volumetrics can only really be a feature of a more general package.

So while the past few months have been devoted to learning how Sunflow works, the long term goal is to incorporate volumetric fractals into the outstanding package that Sunflow is.

http://sunflow.sourceforge.net/index.php
https://fractrace.dev.java.net/

[doncasteel8587]

Two simple questions really:

1: Which 3D rendering program (preferably a raytracer), renders 3 dimensional voxel data I have created externally (perhaps from a text file) ? At minimum, it would be converting 2 color data (i.e. the voxel either exists or it doesn't), but preferably, also optionally taking into account the 'colour' of the voxel.

2: Even more advanced, is there a 3d program which 'looks' for surfaces in the 3D voxel data, and converts these to surface polygons (or for programs like povray, mathematical curves). It would be the equivalent of a 2D structured drawing program tracing the outline of a shape in a bitmap picture. Once again, I'm thinking of the 3D program being able to read my external data, such as ascii data created from a C program. I'm hoping for something a little more advanced than the marching squares (or cubes) algorithm which only allows for 45 degree jumps of lines or polygons.

I'm sorry, I should have pointed out in my earlier reply that VTK http://www.vtk.org/ will do what your looking for, it is however more suited for scientific visualization and falls a little short of "digital art quality" but I've used it to create meshes for importing into Maya.

Here are some examples:

http://casteeld.deviantart.com/art/Itterated-Function-System-001-25963367
http://casteeld.deviantart.com/art/3D-fractal-polished-burl-wood-26059542
http://casteeld.deviantart.com/art/slice12-06-05-000a-26153544