3d modeling

What are voxels and how are they used in 3D modeling?

Some tools in 3D modeling software don’t work in meters, pixels or inches, but in a different unit: voxels, three-dimensional cubes that represent uniform volumes of space.

What is a voxel? What’s the best way to use these funky little cubes? There’s a lot more to the concept than meets the eye.

What are voxels?


Conversion of a torus mesh into voxels.

Voxels are generic units representing a given volume of 3D space. They are essentially small virtual building blocks, playing a role analogous to that of the pixels characterizing a two-dimensional field.

The word itself is an allusion to the word “pixel”, only in a volumetric context as opposed to a two-dimensional graphical context. Voxels are extremely rare as the default rendering agent for most mainstream 3D programs like Blender, but they are still very relevant to the field of 3D modeling and CGI.


A side-by-side voxel comparison.

Here you can see some voxels in action in Blender. You may have noticed this option when using the Remesh modifier on an object. What is the difference between these two types of rendering protocols?

  • They are sampled throughout the model, whereas a polygonal mesh is just a skin full of empty space.
  • Voxels have no native position – they are relative, with each volumetric value determined by the relationships they share.
  • They are coordinate-based and technically do not exist outside of the final rendered image.
  • The voxels all have a fully congruent size, the smallest possible discrete value in a given 3D space.

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Basically, imagine the interior of a large hollow cube with grids covering all six sides of its interior walls. A voxel would be a volume of space equivalent to one unit cubed around all sides.

Voxels are extremely valuable in scientific and medical imaging, as well as particle simulations. They are more true to life in many ways, but are limited in how they can be used directly in 3D modeling. There are, however, many secondary applications of voxels that can certainly help you achieve many interesting and new effects.

Related: Working with UVs in Blender: A Walkthrough for Beginners

How are voxels used in 3D modeling?


A tree leaf texture created with voxels applied to metaballs.

There are two main ways to implement voxels in your own work: as a mathematical framework informing different operations and reconstructions of your model, or as literal building blocks, creating 3D art in a number of styles. of retro and low-poly modeling.

You can either start with blocky units as you build your design or spend some time based on your model and retopologize it in a voxel style or use a tool to do it for you procedurally and Automatique.

We suggest trying both approaches when you’re first starting out. You can “vox” a model or family of objects, resulting in a unique look that can look impressive in a variety of contexts, depending on the scale and resolution you choose. for voxel retopology.

You can use voxels to create complex objects in a low-poly style. Using them on a few metaballs, for example, creates something that looks like a very stylized tree of leaves, as shown above.

They are extremely light on your system by nature, making them perfect for adding elements to the scene without compromising performance. Like all the other geometric primitives you’re used to using, voxels are much more than their mathematical roots.

Related: Simple 3D Modeling Projects for Beginners

What is a voxel if not the precursor to greatness?

There are a million ways to rotate voxels in a 3D modeling program. The definition of “voxel” matters less than how you use them. It all depends on you and what you like to do. Try everything and see what you can find.


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