When we talk about digital 3D images, what comes to your mind? You probably remember the last movie or animation you saw. Maybe if you are a fan of computer games, you imagine your favorite game. If you are not a fan of movies and animations or a fan of computer games, you must have seen many 3D images in posters and magazines.
The 3D design process is a complex task. A 3D designer designs 3D objects using special 3D design software (such as Blender). But this is not the end! After designing and modeling the objects, other steps must be done so that the result becomes something that you and I see every day in movies, games, animations, advertisements, etc.
This process, which is done after designing and modeling, is called rendering.
In this article we talk about what is a rendering engine? Why is it important? What methods does it have? And finally, we will introduce the most popular rendering engines of Blender software. So stay with us.
Table of Contents
What is 3D rendering?
In simple words, the rendering engine is a software that takes 3D models and all its information such as light and texture and turns them into a 2D image.
In other words, the rendering engine takes a 3D object and produces the final output with proper lighting, camera settings, shadows, atmosphere, special effects, etc., resulting in attractive, 3D images.
The things and objects designed in the 3D modeling stage are not attractive and real. We can use the rendering of these objects to give them new life and make them look more beautiful and natural.
In what industries are rendering engines used?
3D modeling and rendering gives game developers, filmmakers, engineers, artists, architects and 3D design enthusiasts the opportunity to create objects and characters out of the real world. For example, you can’t photograph a dragon because it doesn’t exist externally. But you can create a 3D model of it and render the model as if the dragon has lived with humans for a long time, like street cats!
Almost all businesses can use 3D modeling and rendering, for product design or marketing purposes. Some of the industries in which the use of 3D rendering engines is necessary are:
Filmmaking and animation
The number of 3D animated films released in the last three decades is an undeniable evidence of how 3D rendering has helped the film and animation industry. It is no longer surprising to see movies where scenes are created by combining real characters with computer graphics (CGI).
Architecture
Another industry that is closely related to 3D modeling and rendering is 3D architectural design. The only possible way to visualize huge buildings, tall skyscrapers, bridges, dams and other structures without making full-scale prototypes is to create realistic 3D renderings of them. 3D rendering software can also create simulations of building performance, the impact of natural disasters, and wear and tear so that any structure can be improved before it is even built.
Automobile manufacturing
Automotive designers use 3D modeling and rendering to provide realistic aerodynamic body designs using virtual performance tests and simulations. Designers can play with different materials to meet the desired hardness and durability parameters.
Virtual reality
The world of simulated digital environments continues to grow. As technology advances, the simulated environment using real-time rendering methods promises an immersive and realistic escape from the physical world.
Other industries that use 3D modeling and presentation a lot include the fashion industry (animated models of clothing on the body), medicine (real presentation of 3D scanned organs for more accurate diagnosis and treatment of diseases). And of course production (creating prototypes of products virtually).
What is the purpose of rendering?
Renderings created by 3D rendering software often contain an entire scene containing multiple 3D objects rather than a single model.
One of the main purposes of rendering is to allow viewers to view objects in the form of images or videos, captured from specific points of the scene, to get the best view of all available objects. The scene usually has a focal point (the main object to show) and additional models or scenery to make things more realistic, such as trees, buildings, clouds, sky, sun, smoke, fog, moving vehicles, animals, etc. .
Another important purpose of rendering is perspective, or how one object appears in the scene relative to another. Comparison of size, light and shadows, distance and behavior of objects should be considered.
Types of rendering methods
There are two main methods in rendering: Real-time method and Offline method.
The main difference between these two methods is the speed of processing 3D models and of course the overall quality of the final product. In general, the rendering process is expensive for two obvious reasons: hardware and software.
The hardware used to perform rendering operations must be strong and able to perform heavy calculations. Choosing the right hardware for this task can be expensive.
On the other hand, the software is a bit more affordable. There are a variety of 3D design software that cost thousands of dollars a year, but you can use free 3D modeling software that also supports rendering functions, such as Blender, which is also open source.
Real-time method
This method, which is mainly used in interactive graphics and games, focuses a lot on speed. In this method, due to its interactive nature, the images must be processed very quickly. For example, in a heavy game with complex algorithms, it is challenging to predict what the player will do next in each environment or scene, and therefore the 3D scenes must be recreated in real-time with interaction.
In order for the motion and scene changes to look smooth, the rendering speed should be around 20 frames per second. Anything less than 18 frames per second (fps) will result in messy and poor rendering of 3D models. The ideal speed for rendering is 24 frames per second, as this is the minimum the human eye can perceive to see the image moving.
Offline method
For anything other than interactive graphics or games, rendering speed is not an issue. If the real-time rendering relies on dedicated graphics hardware, the offline rendering method can perform this process using multi-core CPUs. When we use this rendering method, the rendering speed will be longer, but the calculations will be more accurate, and as a result, the final product will have a higher quality than the real-time method.
Offline rendering is often used in animations and movies where visual effects and details require a much higher standard.
Rendering techniques
Among the most common computing techniques used in 3D rendering are ScanLine, Ray tracing and Radiosity. Each technique has a set of advantages and disadvantages, which make them suitable alternatives in different situations.
Scan Line
This technique is mostly used when speed is important. Therefore, it is the technique of choice for real-time or interactive graphics. In this technique, instead of providing 3D images on a pixel-by-pixel basis, which can take a long time even for a single frame, line scan does it on a polygon-by-polygon basis. If pre-calculated lighting information is used, this process can reach 60 frames per second. Especially when used in a modern and advanced computer hardware system.
Raytracing
The focus of this technique is on light and brightness. In this method, for each pixel in an image or scene, light rays are analyzed to determine the reflection and refraction of light depending on the type of material in the scene. The color of each pixel is also calculated based on the behavior of light towards objects in its path.
Radiosity
If ScanLine is based on polygons and pixel-by-pixel raytracing, the Radiosity method is surface-oriented. The main focus of this method is on light radiation and its effect on the color of surfaces, which of course indirectly includes the analysis of lighting.
Introducing the best rendering engines for Blender software
As promised, in this section we have compiled a list of the best and most popular rendering engines for Blender design software:
1) Cycles
Cycles is one of the most popular software used for rendering Blender models? Cycles is known as one of the easiest rendering software to learn. This great tool is used for a variety of purposes, and is especially great for creating animations.
2) Eevee
The eevee rendering engine was introduced after cycles as a software that uses the real-time method. As we have already explained, this software has a very high speed due to the use of real-time method.
3) luxCoreRender
The luxCoreRender rendering engine is an open source software with a focus on realism and physical accuracy. This software provides complex path tracking techniques to retrieve more detailed information from a 3D scene. In this technique, in addition to analyzing the rays of the camera, rays from the light sources in a 3D scene are analyzed, which leads to more accurate data of the scene. This makes it suitable to use this rendering engine in complex lighting conditions, such as dimly lit rooms and scenes with transparent and glass elements.
4) Radeon ProRender
Processor manufacturer AMD offers its own free path tracker, which is also available for Blender. Since this rendering engine is relatively young, it is not as complete as Cycles or LuxCoreRender. But it’s an accessible renderer that’s well integrated with Blender. Radeon ProRender is suitable for Blender users working with Mac OS. Because this software fully supports Apple’s Metal graphics library and uses this advantage to speed up the rendering process in the Mac operating system.
5) Octane rendering
When it was created, Octane render was the first and fastest rendering engine that used raytracing. For this reason, this engine is one of the most popular rendering engines in Blender. This software is comparable to Cycles in terms of performance. But Octane offers more realism.
6) Renderman
Renderman is a very special rendering engine developed and used by Pixar. This software is one of the most advanced rendering engines currently available for Blender software.
This software is very fast in complex scenes such as indoor scenes or polygonal scenes. But in smaller scenes it is a bit slower than Cycles or Octane.