Real-time Rendering Third Edition

[Harcourt Ordonez]

Thoroughlyrevised, this third edition focuses on modern techniques used to generate synthetic three-dimensional images in a fraction of a second. With the advent of programmable shaders, a wide variety of new algorithms have arisen and evolved over the past few years. This edition discusses current, practical rendering methods used in games and other applications. It also presents a solid theoretical framework and relevant mathematics for the field of interactive computer graphics, all in an approachable style. The authors have made the figures used in the book available for download for fair use.:Download Figures.

Rendering ... has been completely revised and revamped for its updated third edition, which focuses on modern techniques used to generate three-dimensional images in a fraction of the time old processes took. From practical rendering for games to math and details for better interactive applications, it's not to be missed.

-- The Bookwatch, November 2008

We use cookies and similar tools that are necessary to enable you to make purchases, to enhance your shopping experiences and to provide our services, as detailed in our Cookie notice. We also use these cookies to understand how customers use our services (for example, by measuring site visits) so we can make improvements.

If you agree, we'll also use cookies to complement your shopping experience across the Amazon stores as described in our Cookie notice. Your choice applies to using first-party and third-party advertising cookies on this service. Cookies store or access standard device information such as a unique identifier. The 103 third parties who use cookies on this service do so for their purposes of displaying and measuring personalized ads, generating audience insights, and developing and improving products. Click "Decline" to reject, or "Customise" to make more detailed advertising choices, or learn more. You can change your choices at any time by visiting Cookie preferences, as described in the Cookie notice. To learn more about how and for what purposes Amazon uses personal information (such as Amazon Store order history), please visit our Privacy notice.

It will help you increase speed and improve image quality and learn the features and limitations of acceleration algorithms and graphics APIs. This latest fourth edition has been updated to include a chapter on virtual reality and augmented reality and covers new topics such as visual appearance, global illumination, and curves and curved surfaces.

Real-time computer graphics or real-time rendering is the sub-field of computer graphics focused on producing and analyzing images in real time. The term can refer to anything from rendering an application's graphical user interface (GUI) to real-time image analysis, but is most often used in reference to interactive 3D computer graphics, typically using a graphics processing unit (GPU). One example of this concept is a video game that rapidly renders changing 3D environments to produce an illusion of motion.

Computers have been capable of generating 2D images such as simple lines, images and polygons in real time since their invention. However, quickly rendering detailed 3D objects is a daunting task for traditional Von Neumann architecture-based systems. An early workaround to this problem was the use of sprites, 2D images that could imitate 3D graphics.

Different techniques for rendering now exist, such as ray-tracing and rasterization. Using these techniques and advanced hardware, computers can now render images quickly enough to create the illusion of motion while simultaneously accepting user input. This means that the user can respond to rendered images in real time, producing an interactive experience.

Real-time graphics systems must render each image in less than 1/30th of a second. Ray tracing is far too slow for these systems; instead, they employ the technique of z-buffer triangle rasterization. In this technique, every object is decomposed into individual primitives, usually triangles. Each triangle gets positioned, rotated and scaled on the screen, and rasterizer hardware (or a software emulator) generates pixels inside each triangle. These triangles are then decomposed into atomic units called fragments that are suitable for displaying on a display screen. The fragments are drawn on the screen using a color that is computed in several steps. For example, a texture can be used to "paint" a triangle based on a stored image, and then shadow mapping can alter that triangle's colors based on line-of-sight to light sources.

Real-time graphics are typically employed when interactivity (e.g., player feedback) is crucial. When real-time graphics are used in films, the director has complete control of what has to be drawn on each frame, which can sometimes involve lengthy decision-making. Teams of people are typically involved in the making of these decisions.

Real-time previewing with graphics software, especially when adjusting lighting effects, can increase work speed.[3] Some parameter adjustments in fractal generating software may be made while viewing changes to the image in real time.

The graphics rendering pipeline ("rendering pipeline" or simply "pipeline") is the foundation of real-time graphics.[4] Its main function is to render a two-dimensional image in relation to a virtual camera, three-dimensional objects (an object that has width, length, and depth), light sources, lighting models, textures and more.

The application stage is responsible for generating "scenes", or 3D settings that are drawn to a 2D display. This stage is implemented in software that developers optimize for performance. This stage may perform processing such as collision detection, speed-up techniques, animation and force feedback, in addition to handling user input.

Collision detection is an example of an operation that would be performed in the application stage. Collision detection uses algorithms to detect and respond to collisions between (virtual) objects. For example, the application may calculate new positions for the colliding objects and provide feedback via a force feedback device such as a vibrating game controller.

The application stage also prepares graphics data for the next stage. This includes texture animation, animation of 3D models, animation via transforms, and geometry morphing. Finally, it produces primitives (points, lines, and triangles) based on scene information and feeds those primitives into the geometry stage of the pipeline.

The geometry stage manipulates polygons and vertices to compute what to draw, how to draw it and where to draw it. Usually, these operations are performed by specialized hardware or GPUs.[5] Variations across graphics hardware mean that the "geometry stage" may actually be implemented as several consecutive stages.

Before the final model is shown on the output device, the model is transformed onto multiple spaces or coordinate systems. Transformations move and manipulate objects by altering their vertices. Transformation is the general term for the four specific ways that manipulate the shape or position of a point, line or shape.

In order to give the model a more realistic appearance, one or more light sources are usually established during transformation. However, this stage cannot be reached without first transforming the 3D scene into view space. In view space, the observer (camera) is typically placed at the origin. If using a right-handed coordinate system (which is considered standard), the observer looks in the direction of the negative z-axis with the y-axis pointing upwards and the x-axis pointing to the right.

Projection is a transformation used to represent a 3D model in a 2D space. The two main types of projection are orthographic projection (also called parallel) and perspective projection. The main characteristic of an orthographic projection is that parallel lines remain parallel after the transformation. Perspective projection utilizes the concept that if the distance between the observer and model increases, the model appears smaller than before. Essentially, perspective projection mimics human sight.

Clipping is the process of removing primitives that are outside of the view box in order to facilitate the rasterizer stage. Once those primitives are removed, the primitives that remain will be drawn into new triangles that reach the next stage.

This tutorial is a high-level overview of a basic real-time rendering pipeline. As we mentioned in our last article, real-time simply means that it is doing the rendering immediately (hopefully above 30fps).

In graphics, you place the objects in your scene (model transform), but the camera is always at a fixed position, so you move around the entire world (view transform) so that it aligns to the camera at the distance and angles that you want, then you take the picture.

For perspective view, the view frustum looks like a truncated pyramid. When the computer projects the scene onto a view plane, it takes the far plane and squishes it so that the frustum ends up having parallel planes (like the orthographic frustum). This operation distorts anything that is further from the camera and makes them appear to be smaller than they are, which is how it achieves a perspective view.

Another thing to point out about pixel shaders is that they can get information fed to them from vertex shaders. For example, in the lighting calculations, we needed certain information from the vertex lighting calculations done in the vertex shader.

Matt joined NVIDIA Research in 2018, coming from Google, where he initiated and led the light field capture and rendering project in the VR group for three years. Previously, he has worked on SPMD compilers, started two companies, and worked on both offline and real-time rendering. He has a Ph.D. from the graphics lab at Stanford. His current research interests include the application of machine learning to rendering and real-time ray tracing.

3a8082e126