3D computer graphics
Introduction
3D computer graphics, also known as three-dimensional computer graphics, are graphics that use a three-dimensional representation of geometric data. This data is stored in the computer for the purposes of performing calculations and rendering 2D images. Such images may be for later display or for real-time viewing. Despite the name, 3D computer graphics are typically displayed on two-dimensional displays. They are used extensively in various fields, including video games, movies, architecture, medicine, and scientific visualization.
History
The history of 3D computer graphics can be traced back to the early days of computing. The first significant development was in the 1960s with the advent of vector graphics, which allowed for the creation of simple 3D wireframe models. The 1970s saw the development of raster graphics, which enabled the creation of more complex 3D models and the rendering of these models into 2D images. The 1980s and 1990s saw significant advancements in hardware and software, leading to the development of more sophisticated 3D graphics techniques, such as texture mapping, shading, and ray tracing.
Basic Concepts
Geometry
The foundation of 3D computer graphics is geometry. This involves the mathematical representation of 3D objects. The most common geometric representation is the polygonal model, which uses polygons to represent the surfaces of 3D objects. Other geometric representations include NURBS (Non-Uniform Rational B-Splines) and subdivision surfaces.
Transformations
Transformations are used to manipulate 3D objects. The most common transformations are translation, rotation, and scaling. These transformations are typically represented using matrices, which allow for efficient computation.
Rendering
Rendering is the process of converting a 3D model into a 2D image. This involves several steps, including projection, clipping, and rasterization. There are several rendering techniques, including ray tracing, rasterization, and radiosity.
Shading
Shading is the process of determining the color of a surface based on the lighting conditions. There are several shading techniques, including Phong shading, Gouraud shading, and flat shading.
Texturing
Texturing is the process of applying an image, known as a texture, to a 3D model. This can be used to add detail to the model without increasing the geometric complexity.
Lighting
Lighting is a crucial aspect of 3D computer graphics. It involves simulating the behavior of light to create realistic images. There are several lighting models, including the Phong reflection model and the Blinn-Phong shading model.
Advanced Techniques
Ray Tracing
Ray tracing is a rendering technique that simulates the behavior of light to create highly realistic images. It traces the path of light rays as they travel through the scene, taking into account reflections, refractions, and shadows. This technique is computationally intensive but produces highly realistic results.
Global Illumination
Global illumination is a set of techniques used to simulate the indirect lighting in a scene. This includes effects such as color bleeding, where the color of one object affects the color of nearby objects, and caustics, where light is focused by reflective or refractive surfaces.
Physically Based Rendering
Physically based rendering (PBR) is a rendering technique that aims to produce images that are physically accurate. This involves using physically accurate models for materials, lighting, and camera effects.
Real-Time Rendering
Real-time rendering is used in applications where images need to be generated quickly, such as in video games. This involves using techniques that can produce images at a high frame rate, such as level of detail and occlusion culling.
Applications
Video Games
3D computer graphics are used extensively in video games. This involves creating 3D models of characters, environments, and objects, and rendering these models in real-time. Modern video games use advanced techniques such as PBR and real-time ray tracing to create highly realistic graphics.
Movies
3D computer graphics are also used in movies, particularly in the creation of special effects and animated films. This involves creating 3D models of characters and environments, and rendering these models using techniques such as ray tracing and global illumination.
Architecture
In architecture, 3D computer graphics are used to create visualizations of buildings and other structures. This involves creating 3D models of the structures and rendering these models to create realistic images.
Medicine
In medicine, 3D computer graphics are used for visualization and simulation. This includes creating 3D models of anatomical structures and using these models for surgical planning and training.
Scientific Visualization
3D computer graphics are also used in scientific visualization. This involves creating visual representations of scientific data, such as simulations of physical phenomena or visualizations of complex data sets.
Future Directions
The field of 3D computer graphics is constantly evolving, with new techniques and technologies being developed. Some of the current trends include the use of machine learning for rendering and the development of new hardware, such as GPUs and ray tracing hardware.