Understanding Real-time Rendering, How it Works, and Benefits

Real-time rendering is a technique by which you convert 3D models into 2D images very quickly. This is an oversimplification of the meaning, but we’ll get into the details a bit later. If you’ve played a video game or tried on apparel on an eCommerce app, there’s a fairly likely chance that you used this process. You may even have used it if you've used 3D visuals for your product promotions.

As you can see, many industries make use of real-time rendering to make stunning visuals. If you're also thinking of using it to create photorealistic visuals, you need to know a few things.

Let's dive in...

What is real-time rendering?

Real-time rendering is a technique in computer graphics where 3D visuals are analyzed and produced into 2D images in real time. Unlike normal rendering, where renders are pre-made and stored somewhere for later use, real-time rendering allows the users to interact with 3D scenes as and when the scenes are rendered.

How does real-time rendering work?

We just learned that real-time rendering is where 3D data is instantly turned into 2D images. But... what exactly goes on in this process; how does it work?

• Traditionally, we use rasterization for real-time rendering, where the graphics processing unit (GPU) uses various calculations to convert the positions in 3D space into a 2D space. The new 2D positions are then converted into pixels, after which colors, textures, shadows, and other effects are computed. In the end, you get the final rendered images.
  The main drawback of this traditional technique is that it can sometimes oversimplify the 3D visuals.
• Shaders are used to render visual effects like lighting, reflections, and textures for depth and realism in the visuals.
• The images are then rendered very quickly - generally at a speed of 30 to 60 frames per second (or higher) - to give the illusion of smooth motion.
• And then, when we do 3D optimization, we increase the rendering speeds without hurting the visual quality of the renders.
• Ray tracing is a much newer rendering technique where you create realistic visuals by mimicking the way light interacts with various 3D objects in a scene. Intense calculations are involved here, but you get incredibly realistic visuals, especially when it comes to reflections and refractions.

Difference between offline rendering and real-time rendering

Basis	Real-time rendering	Offline 3D rendering (pre-rendering)
Time taken	The rendering is immediate or real-time	It takes a longer time (hours or days) to render a single image or frame
Timing of display	The render is displayed immediately after the input is received	The render is displayed much later after the rendering process is complete
Hardware requirements	Requires expensive, powerful hardware and software for intensive computations	You can make renders with affordable and less powerful computers
Visual quality	May not be as polished or detailed as pre-rendered images	Offline rendered images and animations are of better quality and are more polished
Purpose	Used for interactive applications like AR, VR, and video games	Premade to be used in regular media for realistic, high-quality visualization

Real-time rendering software

1. Unreal Engine

   

   Unreal Engine is a 3D computer graphics game engine and creation tool developed by Epic Games. It lets game developers create realistic characters, animate various objects in their game world, and render all of it at lightning speeds. You can use it to make games, films, visualize products, build immersive experiences, and so much more.

2. Twinmotion

   

   Another product by Epic Games, Twinmotion is a tool that lets you create high-quality visualizations for product design, architecture, fashion, transport, automotive, etc. If you have been using some other modeling software, Twinmotion makes it easy for you to import the data through its one-click synchronization.

3. Unity

   

   Unity is a game engine developed to create real-time 3D games, apps, and experiences for a number of different platforms. You can use it in various industries, like film, architecture, automotive, etc. Unity uses a direct rendering technique to produce natural-looking lighting and shadows in real time. Thus, developers can see what changes they are making as soon as they are made.

4. Chaos Vantage

   

   Chaos Vantage is a real-time ray tracing tool for exploring and manipulating scenes created in V-Ray. It produces high-quality visualizations for architecture, filmmaking, automotive, product design, and so on. Relying on NVIDIA's RTX GPUs, Chaos Vantage produces realistic results with the help of physically based cameras, lights, materials, and global illumination.

   It can render large scenes with a high polygon count without any lag or limitations. The best part is that users can make edits to the render within the software itself; you don’t need to rely on image editing software.

   Chaos Vantage also supports head tracking and rendering to head-mounted displays (HMD), making it the perfect software for virtual reality applications.

5. Enscape

   

   Developed by Enscape GmbH, Enscape is a real-time rendering tool made for architectural and design companies. You can either use it as a standalone or a plugin in SketchUp, Vectorworks, Rhino, Autodesk Revit, and ArchiCAD.

6. Lumion LiveSync

   

   Lumion LiveSync is a free plugin that forms a real-time rendering connection between Lumion and any other architectural design software. With this feature, users can preview design changes in real time and connect camera angles between Lumion and whichever program they are using.

7. EEVEE by Blender

   

   Blender’s EEVEE is a real-time rendering engine that renders PBR materials while maintaining speed and interactivity. You can use EEVEE (Extra Easy Virtual Environment Engine) interactively in the viewport or use it to produce high-quality final renders.

Benefits of real-time rendering

• Produces renders quickly

  Compared to pre-rendering, it renders 3D scenes at incredibly fast speeds. Therefore, artists and developers can make adjustments and get the real-time preview of the changes. Otherwise, they would have to wait for hours for the render to complete and then edit the render (in case of errors or last minute changes) in a photo editor. Faster rendering speeds mean that the 3D artist can be more creative and experiment with the 3D models before making the final render.

• Allows seamless interaction

  Because it renders visuals lightning quick, it enables seamless interactivity in applications. For example, a player can control how the game character, prop, or objects move. Users can zoom in on a visual, and all the finer details are immediately rendered for a closer examination, like in the case of architectural design. Even on eCommerce sites with integrated product configurators, users can turn the product to view it from all angles or change certain features to customize it.

• Efficient use of resources

  You need powerful computer hardware for real-time rendering if you’re doing it by yourself. But with cloud rendering and rendering farms, you don’t need to purchase the hardware. It also means that not much of your device’s processing power will be used up. That’s precisely why high-quality video games can easily run on lower-end devices.

• Flexibility to experiment

  Some software allows you to preview what the final render will look like as you are working. So, you don't have to wait hours till the render is completed to see if it has come out correctly or if you need to make more adjustments. Since you can see the direct results of your manipulations as and when you are making them, it gives you the freedom to change features to see which version expresses your ideas the best.

• Realistic visuals

  3D specialists are able to use real-time rendering to create highly realistic imagery, making their applications (like games and online shopping) more appealing. Realistic visuals make the experience much more believable for a user, no matter what they are doing.

• Enhances collaborative projects

  Many 3D visualization projects rely on collaboration between different teams who might (sometimes) be in different locations. Some 3D visualization software allows collaboration on projects, and with real-time rendering, all the members can see what changes others have made instantly. Thus, projects are completed on time, and the scope for mistakes is reduced.

The limitations

• Real-time rendering has to seamlessly churn out renders at high frame rates, meaning the render engines need more optimization and performance tuning.
• 3D models can lose some quality and detail during the optimization process.
• You can’t control aspects like lighting, shading, or post-processing because renders must stick to certain rules and standards for compatibility.
• Unless you’re using cloud rendering or rendering farms, real-time rendering can get expensive because you need high-end, powerful computer hardware.

Applications of real-time rendering

1. Video games

   Real-time rendering can quickly render intricate 3D models, naturalistic lighting effects, and dynamic game environments. That's like a blessing for video games because they are very interactive and need to respond to actions fast. So, it's only natural that game developers fully use real-time rendering to create interactive game worlds that players can explore and interact with.

2. Entertainment

   The film and television industry is mostly dominated by offline rendering when it comes to computer graphics. However, real-time rendering is used to cut down on the lengthy post-production involved in creating hyper-realistic CG worlds and special effects. Moreover, the realism it gives CGI visuals improves the overall cinematic experience.

3. eCommerce

   eCommerce is highly competitive, and, unless you've got a really niche product, it’s difficult to stand out from others in the market. So, marketers are using real-time rendering to showcase their products creatively and elevate the customer's online shopping experience.

   The visuals are very realistic, allowing customers to view products in detail from different angles, "try" them on, and change the colors, as if they were in a real store. Every time they interact with the visuals, there’s an instant response, making the shopping experience more believable. So, customers can more accurately tell if a product sits them, looks good on them, or matches their expectations.

   This kind of immediate feedback is almost impossible to get from plain images. That's why you have more eCommerce platforms and online stores integrating augmented reality (AR) so shoppers can virtually try on the products.

4. Architecture and design

   Architects and designers have come a long way from using complicated 2D building plans to creating 3D visuals. Now, many of them are using real-time rendering to make designs that are realistic and interactive so clients can easily see and experience them. Through these visuals, architects and designers can easily appeal to the clients and accurately convey their design ideas. Thus, costly mistakes are avoided, and construction can progress based on informed decisions.

5. Education and training

   Real-time rendering is used to educate and train others in an interactive environment, most commonly through simulations. For example, using flight simulators to train pilots or driving simulators to train for a driver's license. Students or trainees can practice and learn new skills and concepts without putting them in harm's way.

6. VR and AR

   Virtual reality (VR) is where a digital environment is created for the user to immerse themselves in. Digital elements in the virtual world must behave and react the way they would if they were real for the experience to be believable. Real-time rendering is vital here, as it instantly produces renders depending on the inputs received from the user.

   Like VR, augmented reality (AR) also benefits from real-time rendering. But AR overlays digital content on the real world in real time, through your device. So, it is using your device's processing power to render the visuals.

   Normally, low-grade hardware isn't powerful enough to render images efficiently, causing lag and device hangups. However, this issue is negated by real-time rendering, so you don't need high-end devices to use AR.

Over to you now

Real-time rendering will undoubtedly be the future of 3D visualization. It has, no doubt, saved time for artists so they can freely experiment with the visuals and get more creative. Although there are limitations, advantages like smooth motion and interaction far outweigh them. After all, that’s why there’s such a big push for this rendering technique.

So, if you’ve decided to use real-time rendering for your project, we suggest hiring cloud rendering services or outsourcing the work to a rendering farm.

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