Summary
Ray tracing vs. path tracing .. When it comes to dynamic lighting methods, ray tracing and path tracing are two of the most fascinating and challenging techniques that gamers and game developers will have access to in 2024. Both of these lighting approaches offer a significant improvement in realism in comparison to more conventional “baked” lighting techniques. They have the ability to make older games seem far more realistic than their blocky textures and geometry really deserve to be.
Ray-tracing vs. path-tracing
In the event that both ray tracing and path tracing are capable of producing more lifelike lighting in video games, which one is superior? However, what exactly is the difference between the two of them? Let’s take a look at the similarities and differences between ray tracing and path tracing, as well as the reasons why you could see more of one in your favorite games in the years to come.
What is ray tracing?
One approach that is used to simulate lighting in a scene in a realistic manner is called ray tracing. Despite the fact that it was first proposed in the late 1960s, it has only lately been included in real-time games due to the fact that it is very difficult to compute.
A ray is projected into a scene from the perspective of the player in order for ray tracing to function properly. Following each interaction between the ray and an object, the influence of the object on the ray is computed. This calculation takes into account the item’s color, transparency, and orientation. It is necessary to continue tracking the beam as it travels around a scene until it comes into contact with a source of light. This computation is performed for each and every pixel in a scene, which results in a lighting approach that is not only very demanding but also presents an extremely realistic appearance.
The rendering of individual frames might take many hours or even days when using ray tracing, which has been utilized in computer-generated imagery (CGI) for many years. Ray-tracing accelerators, on the other hand, have made it feasible for games to use real-time ray-tracing. This achievement came about as a result of advancements in computational power and the introduction of graphics cards like Nvidia’s RTX and AMD’s RDNA. It was initially limited to shadows and reflections in the first versions, but since then, it has been expanded to include global illumination in an assortment of games.
What is path-tracing?
Real-time dynamic lighting in a scene may be modeled using path tracing, which is a far more current approach. It was developed in the middle of the 1980s and uses a different technique by blasting out hundreds or even thousands of rays at a time from a light source. After that, it tracks the rays as they bounce randomly across a scene. On the surface, this seems to be a lot more difficult than it really is, yet the final result is a render that is much simpler. This is because, rather than monitoring each and every ray from pixel to source, it just records a representation of those rays based on the route that the light is most likely to travel.
The game or program is able to employ a reasonable number of pathways to track a light source since it is achieved by a mix of ray tracing and Monte Carlo simulation. Not only does this make it possible to achieve lighting effects that are similar to ray tracing with a lower overhead, but it also makes it possible to achieve a far higher level of granularity, depending on the capabilities of the system and the parameters that are selected. A larger sample size places a bigger burden on the graphics processing unit (GPU) to draw the scene, but it also generates more information. If you use smaller samples, route tracing will be easier to maintain, but the visual quality will suffer as a result.
Path-tracing, on the other hand, does not provide flawless results. Impressive results are achieved when these techniques are used with denoising algorithms in order to clean up the picture that is produced.
For particular scenes and objects, such as reflecting and refractive items, such as a glass of water, for example, the path-tracing algorithm has to be modified in order to prevent an excessive loss of information in smaller samples. This is necessary in order to optimize the accuracy of the method. In order to ensure that the results are accurate, it is conceivable that the algorithm will just use brute force to ray trace rather than using other methods.
The final product, on the other hand, is a rendered scene that seems to be just as accurately illuminated as a ray-traced image, if not more so, but with the potential for far reduced overhead, particularly when the detail settings are increased. Route tracing is also regarded as more successful in scenes that are well lit because it has more data to work with. On the other hand, ray tracing may be more effective when rendering scenes that have a lot of shadows since it is aware of the actual route that the rays of light would travel.
Does path-tracing look better than ray-tracing?
Ray tracing is a method that is used to accurately mimic real-time lighting because it follows the natural route that light might take as it travels around a scene. On the other hand, the sheer number of computations that must be performed in order to make efficient use of ray tracing is astounding. Even with all of the hardware acceleration that contemporary technology has to offer, it might still struggle to play games that heavily rely on ray tracing. The reason behind this is that the majority of games that support “ray tracing” really just employ ray tracing for a certain section of a scene, generally shadows or reflections.
Path tracing, on the other hand, is capable of producing graphics that are just as powerful, or even more amazing in appearance, while simultaneously placing less of a strain on the rendering machinery. This is the model that is used in some of the most spectacular “ray traced” games that have been released up to this point, such as Quake II RTX, Portal RTX, and the Overdrive mode upgrade for Cyberpunk 2077. Modifications are also being made to previous games, such as Half-Life 2, which are having a significant impact.
Path tracing is a sort of dynamic lighting that is more visually appealing and less harsh than other forms of lighting, and it is perhaps the superior option overall. Ray tracing, on the other hand, is still useful in situations where low path-traced sample sizes would result in issues with visual correctness. As a further point of interest, there are several contemporary instances of conventionally rasterized games, such as Hogwarts Legacy, in which ray-traced or path-traced lighting contributes relatively little to the overall experience while entirely destroying frame rates.
It is quite probable that until graphics cards grow strong enough to draw ray-tracing or path-tracing as readily as rasterization, we will see a mix of lighting effects in future games. This is because each technology has its own niche in the industry.
