Many elements of the visual environment of modern man today are created using computer graphics programs. Neither the architectural or design studio, nor the manufacturers of computer games can do without the visualizations made by 3D artists.
The technology for creating such an image - photorealistic or imitating various art techniques - consists of several technological steps. A render is the most important of them, often the final one, on which the final result depends.
Origin of the term
The word "rendering" (or "rendering") came, like many things related to IP technology, from the English language. It comes from the old French rendre , meaning "do," "give," "return," "return." The deeper roots of this verb go back to ancient Latin: re is the prefix meaning "back", and dare is "to give."
Hence, one of the meanings of the modern term. Rendering is including the process of reconstructing a planar image based on a three-dimensional model containing information about the physical properties of an object β its shape, surface texture, lightness, and so on.
Render and render
Entered first in the vocabulary of those who are professionally engaged in digital imaging technologies, this word is increasingly used in everyday life. They ask to provide a ready-made render, for example, when ordering furniture - a separate object or the atmosphere of the whole room, and when designing the interior or the whole building, rendering is one of the main means to convey to the customer the meaning of the ideas of an architect or designer.
There is a synonym that is close in meaning and more often used in a normal environment, although more cumbersome - visualization. Among the professionals of architectural or gaming computer graphics, it is customary to have a narrow specialization: there are those who are engaged in modeling - create three-dimensional objects, and those who provide rendering of the finished scene - expose lighting, select a point of view and adjust, and then run the render program.
Definitions
This word has several meanings:
- Rendering, or rendering, is the drawing, the process of obtaining a technical or artistic planar raster image based on three-dimensional digital models created using special software packages - Blender, 3D Max, CINEMA, Maya, etc.
- Rendering is, in fact, the result of such a process - a bitmap picture, a photograph, as well as images of heroes and environments in computer games or video files created by trideshniki used in the production of films - ordinary or animated.
- Render, or renderer, is the name of special software with the help of which the conversion of 3D models into an image takes place. Such programs can be built into the graphics package or used as separate applications: RenderMan, Mental Ray, V-ray, Corona, Brasil, Maxwell, FinalRender, Fryrender, Modo and many others. Renders, like everything related to digital technology, are constantly updated. They differ in the algorithms used to calculate the physical characteristics of the models and their environment. On their basis, entire rendering systems are created that allow you to create your own materials, lamps, cameras, etc.
Render types: online and pre-rendering
There are two main types of rendering, depending on the speed with which the final image should be obtained. The first is real-time rendering, which is necessary in interactive graphics, mainly in computer games. It needs a quick render, the image should be displayed on the screen instantly, so a lot of the scene is calculated in advance and stored in it as separate data. These include textures that determine the appearance of objects and lighting. The programs used for online rendering mainly use the resources of the graphics card and the computer's RAM and, to a lesser extent, the processor.
For rendering scenes that are more complex visually, and also where the issue of speed is not so relevant, when the quality of rendering is much more important, other methods and programs for rendering are used. In this case, the full power of multi-core processors is used, the highest parameters for texture resolution and lighting calculation are set. Rendering post-processing is often used, which allows achieving a high degree of photorealism or the desired artistic effect.
Scene rendering methods
The choice of image acquisition methods depends on the particular task and often on personal preferences and experience of the visualizer. All new rendering systems are being developed - either highly specialized or universal. Today, the most common rendering programs are based on three main computational methods:
- Rasterization (Scanline) - a method in which an image is created by rendering not individual pixel points, but entire faces, polygons and large sections of surfaces. The textures that determine the properties of objects, like the light in the scene, are fixed as constant data. The resulting image often does not reflect promising changes in illumination, depth of field , etc. It is often used in systems for rendering scenes in games and in video production.
- Raytracing - scene physics is calculated based on the rays coming from the lens of the virtual camera and the analysis of the interaction of each ray with the objects that it encounters in the scene. Depending on the quantity and quality of such βbouncesβ, the reflection or refraction of light, its color, saturation, etc. are simulated. The quality of the resulting image is much higher than rasterization, but for its realism, you have to pay an increased consumption of resources.
- Calculation of reflected light (Radiosity) - each point, each pixel of the image is endowed with a color that is independent of the camera. It is influenced by global and local light sources and the environment. This method allows you to calculate the appearance on the surface of the model of color and light reflections from adjacent objects.
Practice shows that the most advanced and popular rendering systems use a combination of all or basic methods. This allows you to achieve maximum photorealism and reliability in the display of physical processes in this scene.
Render sequence
Although the modern approach in computer graphics prefers to separate the render into a separate stage, which requires the availability of special knowledge and skills, in fact, it is inseparable from the entire process of preparing the visualization. If, for example, an interior is designed, the rendering will depend on the type of materials used, and each visualization system has its own algorithm for simulating the texture and texture of the surface.
The same applies to scene lighting methods. Setting up natural and artificial light, the properties of its own and incident shadows, the power of reflexes, and self-illumination effects is the next step in creating a scene visualization. How to set up the render depends on the software used and on the system performance. Each package and visualizer has its own subtleties and nuances.
For example, Corona Renderer has the ability to adjust the settings directly during the development of the final picture. In online mode, you can change the power of the fixtures, adjust the color, sharpness of the image.
Post Processing Render Results
For a specific task, it is logical to use special visualization techniques. In architecture, other visual means are required than when creating a technical illustration. Exterior rendering, for example, often requires the artist to own graphic packages for working with raster images, the most popular of which is Adobe Photoshop. Moreover, this is not always done to increase photorealism. Modern trends in architectural presentation provide for the imitation of hand-made graphics - watercolors, gouache, ink drawing, etc.
High-quality rendering post-processing usually starts with choosing the desired file format, obtained after the program ends. It is accepted that the finished image is saved in layers, using individual color channels. This allows you to achieve high results when reducing all layers into a common image, using a more accurate and finer color setting.
Render and system performance
The implementation of high-quality visualization depends not only on the process software. The final result is affected by the power of the used hardware. This factor especially affects the speed of work - a complex scene is sometimes rendered for several days if the computer does not have sufficient RAM or has a low-performance processor.
How to speed up the rendering and improve the final result if there are not enough resources? You can change the program settings by reducing the resolution of the textures of materials and the final image to reasonable values, changing the parameters of the luminaires so that the light and shadows are calculated in larger sections, without excessive detailing, etc. If there is a network, you can use the batch render when for Images are attracted by the power of other computers.
Render farm
Today it is possible to use the power of remote computer clusters that provide services for batch processing of 3D files. These are high-performance systems capable of visualizing the most complex and rich scenes in a short time. They will cope with any visual effects even when creating long-duration video files.
By contacting the provider of such services, a list of which can always be found on the Internet, having agreed on the cost and conditions for preparing files, you can significantly save on speed and achieve the required level of quality of the final image. At the disposal of such companies is up to several thousand processors and hundreds of terabytes of RAM. The render farm calculates the cost of work based on the size of the source file and the time it takes to render. For example, the cost of one frame with a resolution of 1920x1080, which will take 3 hours to render on standard equipment, is about 100 rubles. The scene is calculated within 8 minutes.
Right choice
The answer to the question of how to render a small and simple in shape object or saturated with visual effects animation presentation of the cottage village, suggests a different approach. In the case of independent performance of such work, it is necessary to correctly select the necessary software and take care of the sufficient power of the computer equipment. In any case, the final stage of the work - rendering - will depend on whether the final result suits you.