Render is what? How do I configure it?

Many elements of the visual environment of modern man today are created using computer graphics programs. Without visualizations made by 3D artists, neither an architectural or design studio, nor producers of computer games can do. The technology of creating a similar image - photorealistic or imitating various artistic techniques - consists of several technological stages. Render is the most important of them, often the final, on which the final result depends.

Origin of the term

The word "render" (or "rendering") came, as well as much, related to IP-technologies, from English. It comes from the old French rendre , meaning "to do", "give," "return," "return." The deeper roots of this verb date back to ancient Latin: re is the prefix meaning "back," and dare is "give."

Hence - one of the meanings of the modern term. Render - this includes the process of recreating a planar image based on a three-dimensional model that contains information about the physical properties of the object - its shape, surface texture, illumination, and so on.

Render and visualization

Entered first into the vocabulary of those who professionally deals with digital imaging technologies, this word is increasingly used in everyday life. To provide a ready renderer request, for example, when ordering furniture - a separate object or furnishings 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 the architect or designer.

There is a synonym, close in meaning and more often used in the usual environment, although more cumbersome, - visualization. Among the professionals of architectural or game computer graphics today it is customary to have a narrow specialization: there are those who are engaged in modeling - creates three-dimensional objects, and those who render the finished scene - exposes the lighting, selects the point of view and adjusts, and then launches the render program.

Definitions

This word has several meanings:

• Rendering, or rendering, is rendering, the process of obtaining a technical or artistic planar raster image based on three-dimensional digital models created with the help of special software packages - Blender, 3D Max, CINEMA, Maya, etc.
• Render is, in fact, the result of such a process - a raster image, a picture, as well as an image of heroes and environments in computer games or created by trideshnikami video files used in the production of films - conventional or animated.
• A renderer, or renderer, is the name of a special software that converts 3D models into images. Such programs can be integrated into a graphics package or applied as separate applications: RenderMan, Mental Ray, V-ray, Corona, Brasil, Maxwell, FinalRender, Fryrender, Modo and many others. Renders, like everything connected with digital technologies, are constantly updated. They differ in the algorithms used to calculate the physical characteristics of models and their environment. On their basis, entire rendering systems are created, allowing you to create your own materials, fixtures, cameras, etc.

Types of rendering: online and pre-rendering

There are two main types of rendering, depending on the speed with which the finished image should be received. The first one is real-time rendering, which is necessary in interactive graphics, mainly in computer games. Here you need a quick render, the image should be displayed instantly, so much in 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 use mainly the resources of the graphics card and the computer's RAM and, to a lesser extent, the processor.

To render scenes that are more complex visually, and also where the speed issue is not so relevant, when the quality of the rendering is much more important, other methods and programs for rendering are used. In this case, all the power of multi-core processors is used, the highest parameters of texture resolution, lighting calculation are set. Often applied and post-processing render, allowing to achieve a high degree of photorealism or the desired artistic effect.

Methods of rendering the scene

The choice of methods of obtaining an image depends on the specific task and often on the personal preferences and experience of the visualizer. All new render systems are being developed - either highly specialized or universal. Today, the most common rendering programs are based on three main computational methods:

• Rasterization (Scanline) is a method in which an image is created by miscalculating not individual pixel points, but entire polygon faces and large areas of surfaces. Textures that determine the properties of objects, like light in a scene, are fixed in the form of 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.
• Ray tracing (Raytracing) - the physics of the scene is calculated on the basis of the rays emanating from the lens of the virtual camera and analyzing the interaction of each ray with the objects with which it occurs in the scene. Depending on the number and quality of such "bounces", the reflection or refraction of light, its color, saturation, etc., are simulated. The quality of the resulting image is much higher than that of rasterization, but for its realism one has to pay a higher expenditure of resources.
• Calculation of reflected light (Radiosity) - each point, each pixel of the image is endowed with a color that does not depend on the camera. It is influenced by global and local sources of light and environment. This method makes it possible to calculate the appearance on the surface of the model of color and light reflexes from a number of located objects.

Practice shows that the most advanced and popular rendering system uses a combination of all or the basic methods. This allows you to achieve maximum photorealism and reliability in the mapping of physical processes in this scene.

Render sequence

Although the modern approach in computer graphics prefers to allocate a render to a separate stage, which presupposes the availability of special knowledge and skills, in fact, it is inseparable from the whole process of visualization preparation. If, for example, the interior design is designed, the renderer will depend on the type of materials used, and each imaging system has its own algorithm for simulating the texture and texture of the surface.

The same applies to the way scenes are illuminated. Adjusting the natural and artificial light, the properties of your own and the falling shadow, the power of reflexes, the effects of self-luminescence - the next step in creating a visualization of the scene. How to configure the render depends on the software used and the system performance. Each package and program-visualizer has its own subtleties and nuances.

For example, Corona Renderer has the ability to adjust settings directly during the development of the resulting image. In online mode, you can change the power of luminaires, adjust the color, sharpness of the image.

Postprocessing renderer results

For a specific task, it is logical to apply special visualization techniques. In architecture, other visual means are required than when creating a technical illustration. Render of the exterior, for example, often requires the artist to own graphic packages for working with raster images, the most popular of which is Adobe Photoshop. And this is not always done to increase photorealism. Modern trends in the architectural presentation provide imitation of hand-drawn graphics - watercolor, gouache, ink drawing, etc.

Qualitative postprocessing of the renderer usually begins with the selection of the desired file format, obtained after the end of the program. Accepted the finished image to be stored layer by layer, using individual color channels. This allows you to achieve a high result when all layers are merged into a common image, using a more accurate and subtle color adjustment.

Render and system performance

The implementation of high-quality visualization depends not only on the software of the process. The final result is affected by the power of the "iron" used. Especially this factor affects the speed of work - a complex scene is sometimes rendered several days if the computer does not have enough RAM or has a low-performance processor.

How to speed up the render and improve the final result, if the resources are not enough? You can change the settings of the program by reducing the resolution of the textures of materials and the final image to reasonable values by changing the parameters of the luminaries so that light and shadows are calculated by larger areas, without excessive detailing, etc. If there is a network, you can use a batch render, Images are attracted to the power of other computers.

Render-farm

Today, it is possible to use the capacities 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 video files of great duration.

By contacting the provider of such services, the list of which can always be found on the Internet, by agreeing on the cost and conditions for preparing the files, you can significantly save on the speed of work and achieve the required level of quality of the resulting 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 the work, based on the volume of the source file and the rendering time. For example, the cost of a single frame with a resolution of 1920x1080, for which rendering on standard equipment will take 3 hours, 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 object in shape or an animation presentation of a cottage community saturated with visual effects presupposes a different approach. In case of independent performance of such work, it is necessary to select the necessary software competently and take care of sufficient power of computer equipment. In any case, from the last stage of the work - rendering - will depend on whether the final result will suit you.