Difference between Scanline Rendering and Raytracing Rendering

Hi, everyone today we are going to discuss the scanline rendering vs raytracing rendering. As we have already discussed in our previous blog about the rendering.


Brief of Rendering :


Rendering is the term from computer graphics, which indicates the process of visualization, imaging, or creation of models with the help of a computer 3D programs.Rendering is very common nowadays for every 3d artist. Today’s as we see it is very cost effective options for the conception of the designs.


Scanline vs Raytracing Rendering :


Scanline Rendering :


Scanline Rendering is an algorithm for visible surface determination, in 3D computer graphics that work on a row-by-row basis rather than polygon-by-polygon or the pixel-by-pixel basis.

The scanline renderer passes a ray from the camera through every pixel of the rendered images. If the ray crosses a mesh face, the color of the pixel is calculated according to the light sources, their angle to the normal of the face, the angle of the camera to that face and some other information. If no face is encountered, the pixel gets the color of the background. In this manner, the renderer scans all pixels line after line.


Raytracing Rendering :


Raytracing is a specific type of rendering technique. The name refers to the way the computer creates the final image — by analyzing the light sources in the scene and computing the paths of the rays produced by those lights. The result is a very realistic image including reflections and caustics, resulting in lighting and shadows that are close to what would be observed in the real world. In raytracing, many different algorithms can factor into the computation of a pixel’s final shade, including the material’s absorption, reflection, transparency, translucency, and refraction characteristics.

What is better among these two?


We would say that scanline is nothing to do with raytracing because scanline is way faster than raytracer. Scanline is the primary and Raytracing is the secondary: best of both worlds. The scanline will render elements of the scene which raytracing don’t require, while the raytracer will handle reflections/refractions, soft shadows, etc. For faster rendering with motion blur, we should set the Primary Renderer to "Rasterizer" instead of Scanline or Raytracing. We still get to use Raytracing as long as it's on under secondary effects. Some 3d artist like RayMAX combines both to give us the speed and the quality in one engine. We need to select which objects have to be raytraced, and if the ray meets such an object, it is traced accordingly, but for all other objects, the normal way of calculation is used. Scanline works with polygons and Raytracing with the mathematical objects. Scanline rendering has also other problems which usually don't exist in raytracing. These include different kinds of perspective correction (textures, z-information, surface lighting, etc. have all be perspective corrected in order to get a correct result), hidden surface removal, etc. In raytracing, we usually don't need to worry about perspective correction as, due to the nature of the raytracing algorithm, we always get the right parameters.


We hope that our description might help you to know the differences.


Thank you.

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