What is Anti-Aliasing?


If you are a gamer, anti-aliasing is a term that you have surely encountered.

If you have seen the term buried deep in your game settings or graphics card properties, it is important to know that anti-aliasing is a noteworthy feature that can make a huge difference to the quality of the visual you experience in-game.

Learning about the basics of anti-aliasing, what it does, and the different varieties of the feature can allow you to choose the right settings for your games for maximum performance and visual detail.

Here, we discuss the most important characteristics of anti-aliasing that you need to know.

What Does Anti-Aliasing Do?

Before we can delve into anti-aliasing and what it does, it is important to understand what aliasing is and how it manifests visually on your screen.

The smallest of the image you see on your computer display or TV is the pixel.

While displays have steadily moved towards higher resolutions that feature millions of pixels, a pixel in itself has a rectangular shape.

This means that every time something round-shaped is rendered on the screen, it is going to have some jagged edges and corners due to the rectangular shape of the pixels in those regions.

If an image contains either horizontal or vertical straight lines, it is easy for the lines to line up with the edges of rectangular pixels.

However, most objects rendered on the screen, especially in games or other graphics applications, are bound to have diagonals and curves.

When these images are rasterized through the use of pixels, these jagged edges are bound to happen.

This is where anti-aliasing comes in. The broad umbrella term “anti-aliasing” actually refers to a variety of methods or techniques, all of which aim to reduce these jagged edges and smooth things out.

The major differences in these different methods lie in the specific way that the edges are handled and the processing power it requires to achieve the desired results.

Needless to say, the quality of the results can also be different using different techniques.

With different anti-aliasing techniques, the jagged transition between pixels that represent a curve or a diagonal is made less jagged using blurring or blending.

This gives it a softer, less defined appearance and makes the visual more realistic as it prevents the jaggedness of the edges from standing out.

Anti-aliasing has been an integral part of graphics card features and the gaming industry for well over a decade now.

However, over time, many different kinds of anti-aliasing have been developed and implemented, each with its own pros and cons.

Types of Anti-Aliasing

Broadly speaking, there are two kinds of anti-aliasing that you can implement. The first involves spatial processing or pre-processing the image before it is finally rendered.

The second involves post-processing or making changes to the image after it has been rendered.

Currently, there are many forms of anti-aliasing that have been integrated in modern graphics cards and implemented in popular games.

Let us explore some of the most important ones.

MSAA or Multi-Sample Anti-Aliasing

This is one of the most preferred modes of anti-aliasing in the market because of the results it can achieve without putting too much load on the system.

It implements a fine balance between visual fidelity and graphics performance.

The way MSAA works involves differentiating between polygons and textures rendered by the GPU.

Usually, the polygon is drawn first denoting the outline of an object being rendered.

Then the polygon is filled with the texture to complete the rendering.

MSAA deals only with the polygons and does not affect the texture in any way.

MSAA smooths out the edges of the polygons by using multiple samples of two or more pixels that are side-by-side to enhance image fidelity.

The more samples it uses, the better the results. However, the load on the system also increases proportionally.

This is why you are usually able to choose between two, four, or eight samples in the MSAA settings in your games.

Under this technique, you can also find CSAA (Coverage Sampling Anti-Aliasing) and EQAA (Enhanced Quality Anti-Aliasing), developed by Nvidia and AMD respectively.

These manufacturer-specific MSAA implementations further cut down on resource use while delivering balanced results.

In both methods, the system intelligently determines the exact polygons that need smoothing and only smooths out those polygons.

SSAA or Super-Sampling Anti-Aliasing

This is one of the very first methods of anti-aliasing to be available to consumers, and also one of the most effective.

However, it uses a heavy amount of system resources to deliver results.

In SSAA, the entire image is rendered at a resolution higher than the display.

Then, the image is downsampled to create a clearer, crisper visual.

Since the entire image is processed before being displayed, this can take a toll on resources, especially in games that are rendered in real-time.

This method can also introduce artifacts in images that contain straight, sharp vertical, or horizontal lines.

FXAA (Fast Approximate Anti-Aliasing) and MLAA (Morphological Anti-Aliasing)

These techniques are very similar in the way they operate.

Basically, the smoothing occurs at the two-dimensional image level without taking into account the specifics of the actual three-dimensional geometry of the image.

FXAA, developed by Nvidia, and MLAA, developed by AMD, can have small variances in the quality of results.

However, these are both techniques that offer an improvement in visual quality with very little performance impact or hardware usage although the resulting image can become blurrier in both cases.

SMAA or Subpixel Morphological Anti-Aliasing

This is an advanced anti-aliasing technique that has quickly gained popularity with manufacturers, developers, and end-users alike.

SMAA uses an intuitive combination of both spatial processing and post-processing to deliver stunning results.

In this method, pixels are smoothed out intelligently with blurring and blending in a manner similar to FXAA and MLAA.

However, SMAA also makes use of intelligent supersampling in order to enhance the whole image.

This represents an excellent increase in anti-aliasing performance, but with less load on the system.

In very little time, it has become one of the most preferred methods of anti-aliasing in the market.

DLSS or Deep-Learning Super-Sampling

The new kid on the block is Nvidia’s DLSS, a method that uses detailed deep learning models to intuitively design clearer and sharper images.

These are then rendered and upscaled using the Tensor cores found in Turing and Volta-based Nvidia graphics cards.

This technology is exclusively used by Nvidia and is set to be updated to the new DLSS 2.0 standard with the launch of the RTX 3000 line of graphics cards.

Apart from these, there are also other types of anti-aliasing that have fallen by the wayside, either due to limited visual improvement or inefficient amounts of load on the system.

Which Anti-Aliasing Techniques Should You Use?

Ask yourself the following questions:

  • How powerful is your gaming hardware?
  • What games are you looking to run?
  • Which anti-aliasing standards are supported in your graphics card?
  • How much do you value crisper, clearer images over fast performance and higher frame rates?

The right anti-aliasing technique for you would emerge from the answers to these questions.

If you are using lower-tier hardware like older graphics cards or integrated graphics, SMAA and CSAA / EQAA can be your best options.

These anti-aliasing methods are tailormade for low-powered hardware.

With these settings, you would be greeted with a noticeable difference in the image quality without having to further sacrifice your frame rates.

If you own mid-range hardware, this is where things can get interesting.

SMAA is still an excellent option at this stage but you can also experiment with running FXAA / MLAA.

However, in the case of the latter techniques, you might have to experiment with your settings to arrive at an optimum position where the anti-aliasing produces acceptable results without taking too much of a toll on your hardware.

With relatively modern mid-range hardware, you might also be able to use MSAA with lower sample sizes.

If you have an all-out gaming PC, MSAA would definitely be an option even with higher sample sizes.

You can also experiment with SSAA to arrive at an optimum setting for the best image quality possible. You might need to sacrifice frame rates or minor graphic details.

However, the law of diminishing returns applies here as there would be very little discernible difference between SSAA at 4X and 8X.

No matter what mode of anti-aliasing you use, you should always tweak your settings to arrive at that perfect balance between quality and performance.

Play with your anti-aliasing settings while also adjusting your resolution, texture quality, anisotropic filtering, shadow quality, and view distance to find the best balance.

Improving Your Gaming Experience

Anti-aliasing is meant to make your experience of graphical content better.

Smoothing jagged edges can always deliver more potent, realistic visuals and in most cases, your use of anti-aliasing would depend on the unique characteristics of individual scenarios.

However, you can always fire up those settings and introduce anti-aliasing to end up with cleaner, crisper visuals that can transform your gaming experience.

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