There are two principal rendering methods. Each has its advantages and disadvantages for different applications.

Rasterization is the standard for real-time graphics, such as computer games. This 3D rendering technology is suited for this task as it balances real-time performance with an acceptable level of quality.

The downside is that this method cannot cope well with complex lighting conditions.

To work around this constraint, several techniques have been developed over the years. For example, “baking” the lighting into the texture reduces strain on rendering power.

Many of the technologies under discussion in our list of 3D rendering software belong to the ray tracing branch of 3D rendering. Raytracing yields a higher degree of quality than rasterization. This process attempts to recreate the path of light rays in a scene, including bouncing off objects, materials, and other variables. The key is tracing every ray of light that hits the virtual camera’s lens back to its source. This approach includes complex calculations that enable even photorealistic images using reflections and refractions. It is commonly used for animated movies and visual effects.

However, this approach to rendering requires higher processing power. Until recently, it was not an option in real-time applications such as video gaming, however recent developments in graphical processing have triggered a shift, facilitating real-time photorealistic graphics. A closely linked method to ray tracing is “radiosity,” which calculates the spreading and diffusion of light.

When browsing for 3D rendering software, you will encounter two recurring terms that are rarely explained: biased, and unbiased rendering. Here is what they mean.

Unbiased 3D rendering software attempts to calculate physically accurate images. That means they trace back the path of a light ray in a mathematically correct manner, without taking any shortcuts. This method can result in longer render times, be labor intensive on your hardware, but yield the most “correct” render at the end. Unbiased rendering is rarely used for huge projects, such as 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 can mean they interpolate between frames, apply the blur, and deploy algorithms ahead of the render, taking educated guesses at the result of the render without actually tracing every ray’s path, as in unbiased rendering using ray tracing. It takes some expertise to fine-tune a biased renderer to produce a convincing result, but some of the tools listed above do a lot to close the gap. On large-scale animation or special effects projects, biased rendering is often the efficient choice in terms of money and time saved.