3D Rendering Software Tech Talk: Rendering Methods
There are two principal rendering methods that are suitable to two very different applications.
Rasterisation is the standard for real-time graphics such as computer games. This 3D rendering technology is suitable for this task as it balances real-time performance with an acceptable level quality.
The downside is that this method cannot cope well with complex lighting conditions. To work around this constraint, a number of techniques have been developed over the years. For example, “baking” the lighting into the texture reduces strain on rendering power.
The technologies under discussion in our list of 3D rendering software belong to the raytracing branch of 3D rendering. Raytracing yields a higher degree of quality than rasterization. This technology attempts to recreate the physical process. The key is tracing every ray of light that hits the virtual camera’s lense back to its source. This approach includes complex calculations that enable even photorealistic images using reflections and refractions. Therefore, it is used for animated movies and visual effects.
However, this approach to rendering requires greater processing power. For this reason, it has not been used in real-time applications like computer games in the past. The recent development of more powerful GPUs has triggered a shift, facilitating real-time photorealistic graphics. Yet another method is called “radiosity”. In addition to raytracing, it calculates the spreading and diffusion of light.
3D Rendering Software Tech Talk: Physically Based Rendering
Another important term you should look out for is “physically based rendering”. It designates a shader method that emulates the physical properties found in real-world materials such as specularity, refraction. Some consider energy conservation the most important factor. It means that an object cannot reflect more light than it receives.
When browsing for 3D rendering software you will encounter two recurring terms that are rarely explained: “biased” vs. “unbiased rendering”. Here is what they mean.
Unbiased 3D rendering software attempt to calculate physically accurate images. That means they trace back the path of a light ray in a mathematically correct manner, without making any shortcuts. This method can result in longer render times. Therefore, unbiased rendering is rarely used for animated movies. Instead, it is found in graphic design and architectural visualization, since render time doesn’t have that much impact on the project’s schedule.
Biased 3D rendering software, in turn, are developed for efficiency. When calculating the paths of light rays, they strategically cheat to cut down the render time. Specifically, this means they interpolate between frames or apply blur. It takes some expertise to finetune a biased renderer to produce a convincing result. But on large scale animation or special effects projects, it is worth to go the extra mile in terms of money and time saved.