What is 3D Rendering?
3D rendering is the final process in any computer animation of bringing images to life.
Whether it takes a few seconds per frame or a few days, by adding, light, colour, shadows, texture or a range of special or optical effects to any animation sequence, rendering takes a standard image and creates something exceptional.
How 3D Rendering Works
At its very core, 3D rendering enables animators to identify each individual element within an image and apply the artistic qualities required to make the animation come to life.
Before rendering, a 3D image is simply a combination of points and lines within a 3 Dimensional space that have been created by the modelling and animation processes.
Rendering takes these mathematical representations and transforms them into clear and realistic images that provide a final image.
This rendered layer can then displayed individually in its own right, or can be combined as one of many layers within a frame to provide a collection of visual effects which work together to create a frame of real time footage.
Rendering can involve tracing a light ray that spreads across a scene or following the flow of liquid to make a realistic image. It provides the solid surface to the shape and provides the texture to the entire image.
For facial animation, it involves manipulation of the skin tones and textures to ensure a realistic quality or for a space scene could be ensuring the space dust reflects and flows in a fluid manner.
See how the rendering on these 3D dimensional objects creates such a different perspective. And when you place this within a 3dimensional scene, one single frame becomes so realistic.
Different Levels of Rendering
The level of rendering required is dictated by the time available to transform the mathematical representation of a 3D picture into a final image.
1. Real Time Rendering
Real time rendering is used when instantaneous results are required. This is most widely used in the gaming or simulation industry where the computer has to translate the actions of the participant into the graphics on the screen as it happens.
To achieve high quality real time rendering dedicated computer based graphics hardware is usually used to translate between 18 to 120 frames per second.
Speed is of the essence, and the higher the power of the computer processor, the greater the possibilities of far more realistic results.
Wherever possible pre-computed files of anticipated textures and models are stored and used to reduce the demand for real time calculation therefore improving the overall animation experience without excessive demands on processing power.
2. Offline Rendering
Offline rendering is a much slower process where incredibly realistic results can be achieved from standard multi-core CPUs.
Non real-time rendering is most often used in films and video where the quality of the end result far outweighs the speed within which the final 3D animation is produced.
Within any animation or video, each frame of the film will have to be rendered individually and can take a few seconds for basic rendering up to several days for the most complex frames.
The predictability of the image means that the end result can be achieved with much higher quality by using much more refined texture and light files than would be possible with a real time solution.
Highly developed rendering software including Renderman, Mental Ray and V-Ray have been designed to support the rendering process and make truly exceptional results possible.
3D Rendering Techniques
The technique used for a rendering a particular piece of 3D animation will depend on the end result required. Of the most popular 3D rendering techniques, all three have their own core benefits which make them the ideal solution in certain situations.
For the most effective results, the best 3D animators will use a combination of many techniques in order to achieve the ultimate vision.
Scanline is one of the quickest forms of rendering which can produce results in a much shorter timeframe than most alternative methods.
This makes it ideal for use within real time rendering situations where speed is of the essence.
Though most rendering techniques will focus on rendering at a pixel level, Scanline focuses at a polygon level. This means shapes are rendered as a whole, making the entire process less specific but incredibly fast.
When used in conjunction with pre-computed material on a high quality graphics processor, it is possible to render up to 60 frames each second using the Scanline rendering technique. This provides a much higher quality result and an outstanding visual experience in a real time environment.
Unlike Scanline, Raytracing rendering is carried out at a pixel level and is achieved by tracing rays of light from the image to the camera.
By applying different textures to the 3D objects the interaction of the light with the object changes and therefore creates the algorithm required for the qualities of that individual pixel.
This is a much more refined process which provides a higher quality of result than the Scanline technique. However such a process takes significantly more time and is therefore only really appropriate for non real-time rendering.
The Radiosity technique of rendering 3D animation focuses on the surface of each object and how it reacts to the light and environment around it.
This makes it ideal for using when intricate work is required to achieve high end texture variables for an object.
Radiosity rendering is often recognised by its ability to be able to graduate between colours and objects to create highly effective optical effects with lights and shadows.
The Benefits of 3D Rendering
The main benefit of 3D rendering is the level of artistic control that is possible within this process.
Within a computer you can do almost anything and 3D rendering ensures that the images you create are realistic and believable and achieve the quality of animation you are looking for.