3D rendering

Common Software

Rendering has a variety of software, such as: each CG software comes with a rendering engine, as well as renderman, vray, etc.

Noun explanation

rendering, English is render, and some put it as coloring, but I am more accustomed to calling Shade as coloring, calling Render as rendering. Because both words of render and shade values ​​are triad from three-dimensional software, although their functions are similar, they have different. Shade is a display scheme, which generally appears in the main window of the three-dimensional software, and the role of the auxiliary observation model as the line block diagram of the three-dimensional model. Obviously, coloring mode is easier to understand the structure of the model, but it is just a simple display, it is called a brightly dark coloring method in digital images. In advanced three-dimensional software like Maya, you can also display simple lighting effects, shadow effects, and surface texture effects. Of course, high quality coloring effect is supported by professional three-dimensional graphic display card, it can accelerate and Optimize the display of 3D graphics. But no matter how it is optimized, it can't turn the displayed three-dimensional graphic into a high quality image. At this time, because Shade uses a real-time display technology, the hardware speed limits it in real time to feed back the reflection in the scene in real time, refraction Waiting for light tracking effect. And in real work, we tend to output models or scenes into image files, video signals, or movie film, which must pass through the render program. The Shade window provides very intuitive, real-time surface basic color effect, depending on the hardware ability, the texture map, the light source affects and even shadow effects, but this is rough, especially without hardware support. Its display is even unreasonable. The render effect is different. It is based on a complete set of programs, the impact of hardware on it is just a speed problem, and does not change the result of rendering, affecting the result is based on what program rendering, such as Is the light shadow tracking or light energy transmission.

Basic Process

First, the camera in the three-dimensional scene must be positioned, which is the same as the true photography. In general, the three-dimensional software has provided four default cameras, which is four main windows in the software, divided into top views, front elevations, side views, and perspective. Most of us rendering perspective rather than other views, the camera's camera is basically followed by the principle of the real camera, so we have three-dimensional performances like the real three-dimensional world. Next, in order to reflect the sense of space, the rendering process should be some "special" work, which is to determine which objects are in front, which objects are behind and those objects are blocked. Space sensation is only reproduced by the occlusion relationship of the object, and many of the three-dimensional people who begin school only pay attention to the shape of the three-dimensional sense and ignore the sense of space. To know that the spatial feelings and the attenuation of the light source, the environment fog, the scenery of the depth is closely linked, and the cloud also has a lot of similar tutorials, you can go see. After the rendering is obtained by the camera, the rendering is obtained, the light source is to calculate the impact of the light source on the object, which is the same as the real world. Many 3D software have default light sources, otherwise we can't see the coloring effects in the perspective, let alone rendering. Therefore, the rendering program is to calculate the impact of each of our light sources added to the scene. Different from the real world, the rendering process often calculates a large number of auxiliary light sources. In the scene, some light sources will irradiate all objects, and some light sources only illuminate an object, so that the original simple things become complicated. After this, is it necessary to use the depth texture shadow or use the light tracking shadow? This often depends on whether or not the transparent material is used to calculate the shadow of the light source in the scene. In addition, after using the area source, the rendering program also calculates a special shadow - soft shadow (only light tracking), the light source in the scene uses the light source effect, the rendering will also spend more system resources. To calculate the results of the effects, especially the volume, also known as light fog, which takes up the system resources, and pay attention to it. After this, the rendering process also calculates the color of the object according to the material of the object, the material is different, the properties are different, and the texture will produce a variety of different effects. Moreover, this result is not independent, it must be combined with the above-mentioned light source. If there is a particle system in the scene, such as flame, smoke, etc., rendering procedures must be "considered".