Most of us are familiar with 2 dimensional and 3-dimensional graphics but have you ever imagined before that how these Graphics actually came into being? Let us tell you. It’s all due to Rasterization. Now, the question comes to your mind what Rasterization is?
It is a method of displaying 3D models on a computer screen by rasterizing them onto a flat 2D plane. A fixed-function hardware component often performs this process for graphics pipelines.
Besides this, Ray tracing also plays a big role in providing Excellent graphics quality. Ray tracing basically is a technique, so computationally intensive that typically it is used to render objects or areas in a scene that benefit from it the most in terms of quality and realism, besides that Rasterization is used to render the remainder of the scene.
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What Exactly Are They?
In rasterization, a vector graphics image is converted into a raster image made up of pixels, lines, dots, etc. That compose a shape.
Basically, rasterization is just converting a scene’s geometry into pixels, without stating how the hue of those pixels should be calculated. The result cannot be photorealistic since shading, especially the physical light is not considered. It is one of the biggest limitations of rasterization.
In comparison with ray tracing, rasterization has the advantage of speed. By using the GPU, the game will construct a 3D image-based mostly on triangles. A shader creates the image you see on the screen by turning these triangles into individual pixels. Real-time rendering is possible with it.
A ray-tracing calculation can create accurate shadows, recursive reflections, refractions, and any reflective light. A rasterized rendering cannot produce accurate shadows, reflections, refractions, or any reflected or bounced light; you must fake these effects or skip them altogether with a rasterized rendering.
The film industry uses Ray Tracing as an offline rendering technique. This is because ray tracing alters each frame’s quality based on how light reflects from every surface in the film.
Although ray tracing is faster than rasterization, because even one ray can be traced and processed easily, the increase in ray counts is exponential, and all the calculations for all those rays will be time-consuming.
After analyzing both of the above we concluded that ray tracing is somehow better than rasterization tracing.
What Are the Forms of Ray Tracing?
There are a variety of ways in which Ray Tracing is implemented in the games that support it. The developer of the game should determine how much Ray Tracing complexity to implement in the game in order to achieve the perfect balance between performance and visual quality.
Depending upon this, the following are the forms of Ray Tracing:
Reflections
When rendering reflections from reflective objects, such as water and glass, the source of light in the scene is used. Ray Traced reflections are used in several popular games, including “Control.”. To render reflections is considerably more computationally demanding, but they actually look phenomenal.
Shadows
The essence of Ray Tracing is to render shadows accurately based on both the source and the position of objects in a scene. Ray Tracing implementation arguably is related to the shadows because it is the simplest and least intensive.
Moreover, we can observe the same changes in shadows in virtual reality as we see in reality due to the movement and angle of the light source.
Ambient Occlusion
A game can be made more realistic and detailed with ambient occlusion. As with shadows, this is also somewhat connected to the same basic idea. By tracing the shadows of objects within a scene using Ray Tracing, ambient occlusion predicts the angle and intensity of shadows.
Global Illumination
The lighting is more realistic when this feature is on. Sadly, because of how much data is being processed, it takes a toll on performance. This is why in terms of intensity; this is the most demanding form of ray tracing.
Full Path Tracing
It’s becoming more and more common for games to be path traced, essentially meaning that everything is ray traced. These games with full path tracing might actually look better because they utilize real-time reflection such as Quake RTX.
Ray Tracing Vs Path Tracing
Ray tracing is another name for path tracing. In the same vein as ray tracing, path tracing was first theorized in 1986 and the results were not so dramatic then.
Have you ever heard of the exponential growth of rays? This can be solved with path tracing. Rays are only produced by a single bounce when using path tracing. Each set of rays shoots off randomly instead of following a set line.
To create the final image, the path tracing algorithm takes a random sample of all of the rays. Thus, various types of light are sampled, but especially global illumination. A unique feature of path tracing is that shaders can emulate the effect.
There was a shader patch previously released for the Nintendo Switch emulator that emulated a global illumination path traced in titles. Despite looking nice, path tracing does not offer the same level of detail as it does in real life.
Using ray tracing, you can trace a ray as a beam of light as it traverses through a 3D field. Create a ray for a single pixel, calculate what polygon it hits first, and color the area accordingly.
Ray tracing works on the premise that you shot a ray, which will generate the primary lightning; however, as the ray bounced, it generated more and more rays, which contributed less to the final lighting. A path-tracing approach appears to be the most reasonable solution to this exponential-ray-increasing problem. Thus, path tracing is nothing more than a fast ray-tracing method.
Advantages of Path Tracing
Down below are given some advantages of Path Tracing:
- Turner Whitted raytracing evolved into path tracing. Ray tracing adheres to the law of exponential growth in the number of rays. With path tracing, this can be resolved. The rays are fired in the random direction for each pixel, rather than one per pixel.
- It can also be used to solve more complex lighting problems with diffuse inter-reflections or caustics, by solving their integral equation based on the Monte Carlo integration method to represent the light transport within the scene. The method enables an image to be generated on a more disciplined level and can reproduce a much richer set of light or surface interactions.
| Rasterization | Ray Tracing |
|---|---|
| Super-Fast. | Time-consuming phenomenon. |
| Best suited for real-time applications. | A lot of optimization is required for real-time processing. |
| Although it does not support complex visual effects, it can produce some of them with a little bit of cleverness. | Can produce amazing images with complex visuals. |
| One primitive is processed at a time. | Processes on an entire ray at a time. |
| Hard to determine things like A is in the shadow of B or vice versa. | Ray knows about everything it intersects with |
| A bit difficult to talk about shadows and other global illuminations. | Easy to talk about shadows and other global illuminations. |
Summing It Up
Ray tracing offers far more photorealistic graphics than what we see today on mobile and desktop devices, but we still need to significantly reduce the gap between ray tracing and rasterized content.
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