What are rendering methods?

Rendering is the process of creating a flat bitmap image (or even a whole chain of such images) based on 2D or 3D models.

In this article we will understand what rendering methods exist. We will discuss their background.

Read on if you are interested!

Scanline

Scanline is an essential method for determining visible surfaces.

Instead of processing each pixel or polygon individually, this technique scans objects line by line from top to bottom, identifying intersecting primitives and storing only the coordinates. While scanline is efficient for fast rough and real-time rendering, it lacks the consideration of physical properties such as shadows, rays, reflections, and nuanced lighting effects that are essential for achieving realism.

Radiosity

Radiosity divides scene surfaces into patches that emit, absorb, and reflect light. Through iterative calculations, the energy interactions of each patch with others are calculated to simulate realistic effects such as secondary reflections, soft shadows, and non-point light sources.

Initially resource-intensive, optimizations and GPU acceleration have made radiosity quite feasible for real-time applications.

Ray Casting

Commonly used in real-time rendering, video game development, and simple animation, ray casting prioritizes speed over complexity.

Objects rendered using ray casting often appear flat and matte, lacking volumetric depth. This method involves setting viewpoints and light sources, calculating ray directions, determining intersection points, and deciding what details are visible from the viewpoint for fast frame rendering.

While suitable for scenarios that require fast rendering without complex hardware requirements, it can sacrifice detail and realism for efficiency.

Ray Tracing

Ray tracing is the simulation of light rays. That is, the path they take, where they fall, and how they are reflected. It is also responsible for how shadows are created, which surfaces remain visible and which are invisible. It essentially simulates the encounter between the ray and the surfaces in the scene.

Finally, each pixel changes color depending on its location in the scene. This is a very resource-intensive and time-consuming process, which at the same time allows you to achieve a very high quality result and maximum photorealism.

Let's take a look at the theoretical aspects (we promise not to bore you). So, the ray hits the object, the surface, and splits into three other rays:

• Reflected
  
• Shadow
  
• Refracted
  

Depending on the number of directed rays and the number of rays formed after the calculation of the path, the depth of tracing is determined.

This parameter determines how beautiful the final image will be after visualization.
It is important to understand that on weak rigs it will not be possible to realize this process to the full extent.

Even if you want to.

But if you have ever wondered how you get all those beautiful short inserts with the play of light in video games, special effects with light in commercials and movies, all this is the result of the competent use of raytracing.

It is worth saying that the technology is actively developing, and therefore in the near future due to the growth of the performance of video cards ray tracing will be used more widely.

And that's cool!

Path Tracing

Path tracing is very similar to ray tracing. Not only in its name, but also in its essence. Path Tracing allows you to get the most realistic behavior of light in scenes.

As a result, it is one of the most resource-intensive methods of 3D rendering. Unlike ray tracing, this method is more concerned with the physics of light propagation.

But that is not the only difference. For example, in ray tracing, the behavior of light and the decomposition of each ray into its components is determined directly at the moment of collision with the diffuse surface.

In path tracing, on the other hand, the generation of each ray is randomized - within the hemisphere of each individual object. The ray is then traced to the moment of intersection with the light source.

Alternatively, this moment may not occur at all.

Well, those were the main rendering methods. And if you happen to be an architectural designer or even a game developer, you can find a lot of interesting and useful things on our site. For example, there are 3D objects for interior decoration, furniture, lighting, children's rooms and bathrooms.

Developers will also find another section dedicated to Unity and Unreal Engine assets.

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Have fun and good luck!