Voxel Engine: How to Build Your Own 3D Game with Voxels
What are Voxels and How are They Used in 3D Modeling?
If you are interested in 3D modeling, you may have heard of the term voxel. But what exactly is a voxel and how does it differ from other modeling methods? In this article, we will explain what voxels are, how they are rendered, how they store data, how they can be edited, and what are their advantages and disadvantages. By the end of this article, you will have a better understanding of voxels and their applications in various fields.
voxels
Introduction
A voxel is a volumetric pixel that represents a value on a regular grid in three-dimensional space. As with pixels in a 2D bitmap, voxels themselves do not typically have their position (i.e. coordinates) explicitly encoded with their values. Instead, rendering systems infer the position of a voxel based upon its position relative to other voxels (i.e., its position in the data structure that makes up a single volumetric image). In contrast to pixels and voxels, polygons are often explicitly represented by the coordinates of their vertices (as points). A direct consequence of this difference is that polygons can efficiently represent simple 3D structures with much empty or homogeneously filled space, while voxels excel at representing regularly sampled spaces that are non-h [assistant](#table) Article with HTML Formatting ```html What are Voxels and How are They Used in 3D Modeling?
If you are interested in 3D modeling, you may have heard of the term voxel. But what exactly is a voxel and how does it differ from other modeling methods? In this article, we will explain what voxels are, how they are rendered, how they store data, how they can be edited, and what are their advantages and disadvantages. By the end of this article, you will have a better understanding of voxels and their applications in various fields.
Introduction
A voxel is a volumetric pixel that represents a value on a regular grid in three-dimensional space. As with pixels in a 2D bitmap, voxels themselves do not typically have their position (i.e. coordinates) explicitly encoded with their values. Instead, rendering systems infer the position of a voxel based upon its position relative to other voxels (i.e., its position in the data structure that makes up a single volumetric image). In contrast to pixels and voxels, polygons are often explicitly represented by the coordinates of their vertices (as points). A direct consequence of this difference is that polygons can efficiently represent simple 3D structures with much empty or homogeneously filled space, while voxels excel at representing regularly sampled spaces that are non-homogeneous or filled with complex detail.
Voxels are used in various fields such as computer graphics, medical imaging, geospatial analysis, and gaming. Some common uses of voxels include:
Creating realistic terrain and landscapes with varying elevation, texture, and vegetation.
Simulating physical phenomena such as fluid dynamics, fire, smoke, and explosions.
Reconstructing 3D models from scanned data or images.
Generating procedural content such as caves, dungeons, and planets.
Rendering volumetric effects such as fog, clouds, and light scattering.
Voxel Rendering
Voxel rendering is the process of displaying voxels on a screen or display. There are different methods and techniques for voxel rendering depending on the type and format of the voxel data, the desired visual quality and performance, and the hardware capabilities. Some common methods and techniques for voxel rendering include:
Ray casting: This method involves tracing rays from the camera through each pixel on the screen and sampling the voxel data along the ray until a hit or an exit condition is met. The color and intensity of the pixel are determined by the sampled voxel value and optionally by lighting and shading calculations. Ray casting can produce high-quality images with realistic lighting effects, but it can also be computationally expensive and slow.
Splatting: This method involves projecting each voxel onto the screen as a point or a small square (splat) with a certain color and opacity. The splats are blended together to form the final image. Splatting can be faster than ray casting and can handle semi-transparent voxels, but it can also suffer from aliasing artifacts and low resolution.
Polygonization: This method involves converting the voxel data into a polygon mesh that can be rendered using conventional rasterization techniques. Polygonization can take advantage of hardware acceleration and existing graphics libraries, but it can also introduce errors and artifacts due to approximation and simplification.
The following table shows some examples of voxel rendering in different applications:
Application
Voxel Rendering Method
Example Image
Minecraft
Polygonization
No Man's Sky
Splatting
Dreams
Ray casting
Voxel Data
Voxel data is the information that is stored in each voxel or in the voxel grid as a whole. Voxel data can include various attributes such as color, opacity, density, material, normal, etc. Voxel data can also be scalar, vector, or tensor depending on the type and number of values per voxel. For example, a scalar voxel data can store a single value such as temperature, while a vector voxel data can store three values such as velocity.
There are different data structures and formats for voxel data depending on the application and the purpose of the data. Some common data structures and formats for voxel data include:
voxel art
voxel engine
voxel editor
voxel terrain
voxel models
voxel games
voxel sculpting
voxel ray tracing
voxel animation
voxel generator
voxel world
voxel maker
voxel painting
voxel lighting
voxel software
voxel tutorial
voxel design
voxel rendering
voxel minecraft
voxel sandbox
voxel graphics
voxel studio
voxel pixel art
voxel shaders
voxel assets
voxel builder
voxel characters
voxel space
voxel magicavoxel
voxel resolution
voxel physics
voxel converter
voxel sprites
voxel rpg
voxel blender
voxel texture
voxel map
voxel mesh
voxel cloud
voxel optimization
voxel collision detection
voxel destruction
voxel marching cubes
voxel vr
voxel unity3d
voxel unreal engine
voxel godot engine
voxel roblox
voxel qubicle.
Regular grid: This is the simplest and most common data structure for voxel data. It consists of a fixed-size array of voxels arranged in a regular pattern. Each voxel has the same size and shape (usually cubic) and can be accessed by its index in the array. A regular grid can store any type of voxel data, but it can also waste a lot of memory if the voxel space is sparse or contains many empty or uniform voxels.
Sparse grid: This is a variation of the regular grid that uses a hash table or a tree structure to store only the non-empty or non-uniform voxels. Each voxel has a unique key or address that is used to locate it in the hash table or the tree. A sparse grid can save memory and improve performance for sparse or heterogeneous voxel spaces, but it can also introduce overhead and complexity for accessing and modifying the voxels.
Octree: This is a special type of sparse grid that uses a hierarchical tree structure to store the voxels. Each node in the tree represents a cubic region of space that can be subdivided into eight smaller regions (children nodes) if needed. Each leaf node in the tree contains a single voxel or a pointer to a voxel array. An octree can adapt to the level of detail and resolution of the voxel space, but it can also suffer from fragmentation and imbalance issues.
SVO: This stands for sparse voxel octree, which is an optimized version of the octree that uses a linear array to store the nodes instead of a tree structure. Each node in the array has a fixed size and contains information about its children nodes (such as their offsets and masks). An SVO can reduce memory usage and improve cache efficiency compared to an octree, but it can also require more complex algorithms for traversal and manipulation.
The following table shows some examples of voxel data formats in different applications:
Application
Voxel Data Format
Example Image
CT scan
Regular grid with scalar values representing density
Weather simulation
Sparse grid with vector values representing wind speed and direction
3D printing
Octree with scalar values representing material type
Ray tracing
SVO with color and opacity values representing surface properties
Voxel Editors
. Voxel editors are software tools that allow users to create and modify voxel models. Voxel editors can vary in their features and functions, but they typically provide the following capabilities:
Drawing: This allows users to add, remove, or change voxels in the voxel space using various tools such as brushes, erasers, fillers, etc. Users can also choose different colors, shapes, and sizes for the voxels.
Transforming: This allows users to move, rotate, scale, or deform the voxel model or parts of it using various tools such as handles, gizmos, lattices, etc. Users can also apply different operations such as mirroring, cloning, extruding, etc.
Importing and exporting: This allows users to import voxel data from external sources such as files, images, scanners, etc. or export voxel data to external formats such as files, images, meshes, etc. Users can also convert voxel data between different formats and resolutions.
Rendering and previewing: This allows users to see how the voxel model looks like on the screen or display using different rendering methods and settings. Users can also adjust the lighting, shading, and camera parameters to enhance the visual quality and realism of the voxel model.
Animating and simulating: This allows users to create and edit animations or simulations for the voxel model using various tools such as keyframes, curves, bones, physics, etc. Users can also control the speed, timing, and looping of the animations or simulations.
The following table shows some examples of voxel editors and their outputs:
Voxel Editor
Output Image
MagicaVoxel
Voxatron
Goxel
Qubicle
Voxel Advantages and Disadvantages
Voxels have some advantages and disadvantages compared to other modeling methods such as polygons or splines. Some of the benefits and drawbacks of using voxels are:
Advantages:
Voxels can represent complex and irregular shapes with high fidelity and detail.
Voxels can support dynamic and interactive changes such as sculpting, carving, or destruction.
Voxels can enable realistic and immersive effects such as shadows, reflections, or ambient occlusion.
Voxels can be easily generated and manipulated using procedural algorithms or mathematical functions.
Disadvantages:
Voxels can consume a lot of memory and processing power, especially for large or high-resolution voxel spaces.
Voxels can suffer from aliasing or staircasing artifacts due to the discrete nature of the voxels.
Voxels can be difficult to animate or deform using traditional methods such as skinning or morphing.
Voxels can be incompatible or inefficient with some existing graphics hardware or software that are designed for polygons.
The following table shows some examples of situations where voxels are preferable or not:
Situation
Voxel Preference
Reason
Modeling a smooth and organic surface such as a human face
Not preferable
Voxels may not be able to capture the subtle curves and features of the surface without using a very high resolution, which may be impractical or unnecessary.
Modeling a rough and natural surface such as a mountain range
Preferable
Voxels can easily represent the variations and details of the surface without requiring complex geometry or textures.
Modeling a simple and regular shape such as a cube or a sphere
Not preferable
Voxels may waste a lot of space and resources for representing a shape that can be easily defined by a few vertices and faces.
Modeling a complex and irregular shape such as a cloud or a firework
Preferable
Voxels can capture the shape and dynamics of the object with high accuracy and realism, while also allowing for volumetric effects such as lighting and shading.
Conclusion
In this article, we have learned what voxels are and how they are used in 3D modeling. We have seen how voxels are rendered, how they store data, how they can be edited, and what are their advantages and disadvantages. We have also seen some examples of voxel applications in various fields. Voxels are a powerful and versatile modeling method that can offer many benefits and possibilities for creating realistic and immersive 3D content. However, voxels also have some limitations and challenges that need to be considered and addressed. If you want to learn more about voxels, here are some tips and resources that you can use:
Try out some voxel editors: The best way to learn about voxels is to experiment with them yourself. You can download some free or paid voxel editors online and start creating your own voxel models. Some popular voxel editors include MagicaVoxel, Voxatron, Goxel, Qubicle, etc.
Read some voxel tutorials and guides: There are many online resources that can teach you the basics and advanced topics of voxel modeling. You can find some tutorials and guides on websites such as Voxel School, Voxel Wiki, Voxel Art Academy, etc.
Watch some voxel videos and demos: There are many videos and demos that can show you the amazing results and effects that can be achieved with voxels. You can find some videos and demos on platforms such as YouTube, Vimeo, Steam, etc.
Join some voxel communities and forums: There are many online communities and forums where you can interact with other voxel enthusiasts and experts. You can ask questions, share your work, get feedback, learn new tips and tricks, etc. Some popular voxel communities and forums include Reddit (r/voxel), Discord (Voxel Art), Twitter (#voxelart), etc.
Frequently Asked Questions (FAQs)
Here are some common questions that people may have about voxels:
What is the difference between vox What is the difference between voxels and pixels?
Voxels and pixels are both units of digital representation, but they differ in their dimensionality and usage. Pixels are two-dimensional (2D) elements that form images on a flat surface, while voxels are three-dimensional (3D) elements that form volumes in a cubic space. Pixels are used for displaying and manipulating 2D graphics, while voxels are used for modeling and rendering 3D objects.
What is the difference between voxels and polygons?
Voxels and polygons are both methods of 3D modeling, but they differ in their approach and structure. Polygons are geometric shapes that are defined by their vertices (points) and edges (lines), while voxels are volumetric units that are defined by their values and positions. Polygons are used for creating smooth and continuous surfaces, while voxels are used for creating solid and discrete volumes.
What are the advantages of voxels over polygons?
Voxels have some advantages over polygons in terms of realism, detail, dynamics, and generation. Voxels can represent complex and irregular shapes with high fidelity and detail, while polygons may require a lot of geometry or textures to achieve the same effect. Voxels can support dynamic and interactive changes such as sculpting, carving, or destruction, while polygons may require complex algorithms or physics to handle these operations. Voxels can also be easily generated and manipulated using procedural algorithms or mathematical functions, while polygons may require manual modeling or editing.
What are the disadvantages of voxels over polygons?
Voxels have some disadvantages over polygons in terms of memory, performance, animation, and compatibility. Voxels can consume a lot of memory and processing power, especially for large or high-resolution voxel spaces, while polygons can be more efficient and optimized for rendering. Voxels can also suffer from aliasing or staircasing artifacts due to the discrete nature of the voxels, while polygons can produce smoother and cleaner results. Voxels can also be difficult to animate or deform using traditional methods such as skinning or morphing, while polygons can be more flexib