What is Anti-Aliasing?

If you have ever taken a look into the graphics settings of a computer game, you’ve probably seen a feature called anti-aliasing. It’s a popular feature that can be found on most modern game menus. Anti-aliasing is designed to improve the graphics quality of your game. While the concept may be simple enough, there are several types of anti-aliasing systems out there. Some are more taxing on your computer than others.


What Does Anti-Aliasing Do?

The whole purpose of anti-aliasing is to smooth out rough edges and produce a more realistic appearance. Millions of pixels are used to produce images on your screen. These pixels are so tiny that most people are unable to see them with the naked eye. This is especially true with high-resolution displays.

Generally, the pixels will do a good job of working together to create smooth curves and edges. However, small artifacts can occur and ruin the image.

You see, pixels are all square or rectangular in shape. This is fine for creating square graphics. But, most things with a focus on realism use curved shapes. Take, for example, character models and items in the background.

No matter how many pixels a screen has, there’s no way to create a truly smooth curve with square-shaped pixels. Oftentimes, rounded shapes can appear to have jagged edges. This staircase effect is what’s referred to as “aliasing.”

An anti-aliasing system is purpose-built to get rid of that jaggedness using clever processing.


Available Anti-Aliasing Options

How an anti-aliasing feature works depends on the type of system your graphics card uses.

The most common Is called MSAA, or Multi-Sampling Anti-Aliasing. It’s a pretty efficient system that uses samples to fill in those edges. The GPU will analyze the jagged edges and take upwards of 8 color samples. Then, it will smooth things over by blending the colors with the edges.

Nvidia and AMD have their own proprietary systems that are similar to MSAA. Nvidia uses a technique called CSAA, or Coverage Sampling Anti-Aliasing. AMD has EQAA, or Enhanced Quality Anti-Aliasing. Both systems work on the same principles as MSAA, but they are much more efficient. They work great on their respective graphics cards and can reduce resource load significantly.

Next up, there’s FXAA. FXAA stands for Fast-Approximate Anti-Aliasing. As you can guess, this technique is one of the fastest and least taxing on your system. Rather than using samples, blurring is applied. It’s great for low-end PCs, but it may produce a noticeable blurriness.

TXAA, or Temporal Anti-Aliasing, combines the best features of FXAA and MSAA. These systems apply subtle blurring while also using color samples to mask any jagged edges. It’s considered to be better than FXAA, but you still may notice the blur.

Finally, we have SSAA. Super-Sampling Anti-Aliasing. Great for powerful PCs, this technique does use blurring or sampling. Instead, the graphics card will render the game at a higher resolution than needed. Then, it will downscale it. This increases pixel density, making those jagged edges very difficult to see.


How Does Anti-Aliasing Impact Performance?

Anti-aliasing is another step that your GPU has to take to produce an image. So, there will be a performance impact. Some methods are more noticeable than others. For example, MSAA with a high number of samples may produce significant lag.

The key to using anti-aliasing features is to match your system setup with the method you use. Low-end computers can benefit from FXAA. Standard mid-range machines do well with MSAA or TXAA. If resource-hogging isn’t an issue, you can go with SSAA to get the best results possible.