What is real time rendering? A quick & comprehensive overview

Have you ever played a video game that made you feel like you were truly immersed in a virtual world? Or watched a movie with such realistic visuals that you forgot you were looking at a screen? These experiences are made possible by the magic of real-time rendering.

Real-time rendering is a technique used in the world of computer graphics to create and display 3D images in real-time. It is the secret ingredient that makes our favorite video games and movies come to life. Real-time 3D rendering allows us to interact with and explore virtual environments that look and feel like the real thing.

But how does real-time rendering work? In this article, we’re going to take a deep dive into the world of real-time computer graphics, exploring its applications, techniques, advantages, and much more. So fasten your seat belts and get ready for a crazy journey through the fascinating world of real-time rendering! 

What is real time rendering?

Real time rendering is the process of creating computer graphics with a high enough speed to be displayed in real-time. This means that images are generated and displayed “on the fly”, rather than being pre-made and stored for later use. Real time rendering involves the use of powerful computer hardware and specialized software to optimize the rendering process and achieve high frame rates, allowing for instant response to user input or changes in the scene. 

Real-time 3D rendering is one of the types of 3D rendering and is widely utilized in video games, virtual reality, and other interactive applications where it’s crucial to achieve low latency and high graphics speed to create an immersive experience. This technology enables you to construct intricate 3D scenes featuring dynamic lighting, shadows, reflections, and other visual effects that can be updated in real-time in response to user input or changes in the scene.

Real-time graphics is different from pre-rendering or other types of 3D visualization, which can take much longer to create a single image or frame. The main goal of real time rendering is to make the image look as realistic as possible. Typically, this means that images should appear at 25 frames per second to look realistic and natural to the human eye. If the rendering speed will be below 20 frames, the viewer will feel uncomfortable from the scene observing jerks and slow motion.

To help you better understand what real time rendering technology is, we have selected a great video from Eduonix for you. Check it out and keep reading – there’s more to come.

How does real time rendering work?

Any 3D rendering process involves converting a 3D model into a 2D image. Real time rendering usually includes three main stages: geometry processing, shading, and rasterization. Let’s consider each of them.

The rendering process optimization

The optimization process plays an important role in creating smooth rendering in games and interactive scenes. Developers have to use various tricks to reduce the load on the rendering engine to minimize the number of forced miscalculations and achieve the desired rendering speed. This includes lowering the quality of 3D models and textures, as well as writing some light and terrain information into pre-baked texture maps. And optimization techniques such as level of detail (LOD) and shadow clipping help ensure that only the necessary parts of the scene are rendered at any given time. In turn, ray tracing minimizes losses and helps create even more realistic and immersive visual effects. We’ll talk about this further. 

Real time rendering capacity: CPU or GPU?

It’s worth noting that real-time rendering works on specialized hardware, such as graphics processing units (GPUs) and central processing units (CPUs), to quickly and accurately generate and display images in real-time. However, with the ever-increasing capabilities of real-time rendering, the requirements for hardware are also growing – it needs to be as fast and efficient as possible. That is why it is recommended to use graphics processing units (GPUs), which are specially designed for the intensive computing required to render high-quality graphics in real-time. This allows you to speed up the rendering process and reduce the load on the central processing unit (CPU) and free up its computing power for other tasks.

What’s the difference between pre-rendering and real-time rendering?

Pre-rendering is the process of creating a static image or video in advance using specialized software and then saving it for farther utilization. This creates a highly polished and finished product but can be time-consuming and limited in terms of interactivity. You can learn more about it in our blog post “What is 3D rendering?”

On the other hand, as we mentioned, real-time rendering is the process of creating images and videos in real-time, using powerful computer hardware and specialized software. This creates more dynamic and interactive visuals but may require more computing power and may not be as polished as pre-rendered images and animations.

That is, the key difference between pre-rendering and real-time rendering is the level of time and capacity needed to generate computer graphics. Other differences include the level of interactivity and flexibility. While real-time rendering is typically used for interactive applications such as video games, VR, AR, etc., pre-rendering is typically used to create realistic visualizations for static media or animations.

Watch the video below to see the difference with your own eyes.

Applications of real time rendering

While researching this topic, we concluded that the best way to explain what real-time rendering means is to name the most popular examples of its use. You may not even realize that you have come across this technology in some way. Well, let’s find out. 

Video Games

Of course, it’s impossible to talk about real-time rendering without mentioning video games. This is the most popular example of real-time rendering. The technology allows developers to create immersive interactive environments that respond to player actions instantly. With this technology, you can render complex 3D models, realistic lighting effects, and dynamic environments – all at an interactive frame rate.

Virtual Reality

Another popular example of real-time rendering is virtual reality applications. As with video games, real-time rendering allows you to create realistic environments and interact seamlessly with virtual objects. This results in unforgettable VR experiences that you’ll want to repeat. Additionally, real-time 3D rendering is essential for delivering high-resolution, low-latency image rendering, which is crucial for ensuring a smooth and comfortable VR experience.

Augmented Reality

Real time rendering is useful not only for creating realistic virtual reality environments but also for augmented reality applications. This technique is now widely used in AR applications to overlay real-world digital content in real-time directly from your device. This makes it possible to create functional solutions that are especially useful in the field of commerce – getting an engaging experience from trying on clothes or choosing furniture, app users will make a purchase decision faster and be satisfied with it.

Architecture and design

As you may have learned from our previous articles, 3D visualization has become an integral part of the architectural design process. In recent years, real-time renderings have revolutionized the way architects and designers work. 

By using this technique, they can create interactive and realistic visualizations of their projects, allowing clients to see and “feel the atmosphere” of a future home, office, or shopping center before construction begins. This approach enables architects and designers to establish contact with clients, appeal to their emotions, and convey the design idea as accurately as possible. Moreover, it helps to avoid costly mistakes and make informed decisions about the construction process. Gone are the days of complex diagrams and drawings. Interactive and realistic renderings of buildings, landscapes, and infrastructure projects have become essential tools for many industry professionals.

Film and television

In the world of cinema and television, CGI and CGI animation are the main options for computer graphics. However, there is also a place for real-time rendering. This technique allows filmmakers to quickly and efficiently create highly realistic environments and special effects without the hassle of lengthy post-production work. By using real-time rendering technique, they can create a realistic atmosphere that captivates the audience and contributes to the overall cinematic experience. Therefore, it has become an indispensable aspect of the filmmaking process, allowing directors to bring their ideas to life in a way that resonates with the audience.

E-commerce

As more and more people turn to online shopping, manufacturers and retailers are faced with the challenge of finding ways to effectively market their products. Luckily, real-time rendering has revolutionized the way companies showcase their offerings. 

With this technology, customers can see a product in stunningly realistic detail, as if they were physically in the store. They can interact with the product, view it from multiple angles, zoom in and out, and even change its color. This immersive shopping experience has significantly accelerated the purchasing process, as consumers can make informed decisions faster than ever before. Real-time rendering has also allowed retailers to expand their sales capabilities around the world without having to open physical stores in every country or city. 

Education and training

Real-time rendering is gaining new importance in the field of education and training. Here, it is mainly used to create realistic simulations for training purposes, such as medical or flight simulators. This enables students to practice skills and learn complex concepts in a safe and controlled environment.

8 Key advantages of real time 3D rendering

• Speed: The biggest advantage of real-time rendering is speed. Thanks to lightning-fast render times, artists can explore and adjust scenes and models on the fly, freeing up more time for creativity and experimentation. No more waiting for rendering to complete – you can instantly generate hundreds of images or animations and try out new ideas.

• Interactivity: Real-time rendering technique is a game-changer when it comes to interactivity. It allows users to engage with graphics in a way that was previously impossible. In video games, for instance, players can control their characters’ movements, adding a whole new level of immersion. When it comes to architectural design and interior design, real-time rendering allows you to zoom in and study every detail of the object from all angles. You can tweak the appearance of the object by adjusting its color and material, and even experiment with different viewing angles and times of day with just a few clicks. 

• Efficiency: Real-time rendering can be much more efficient than offline 3D visualization because eliminates the need for the time-consuming process of pre-rendering frames. This can save a lot of time and resources, especially when working with large or complex scenes. 

• Flexibility: Real-time computer graphics offer great flexibility and experimentation advantages, as changes to the scene can be made quickly and easily, and are immediately reflected in real-time. This can prove especially useful in industries like architecture or product design, where rapid prototyping and iteration are essential. For instance, you can easily play around with interior details, experiment with different color combinations of walls, wallpaper, and floors, and see how different design options will look right after making changes. The technology allows you to test various ideas and see how they will look in reality, all while significantly saving time. This enables you to optimize the design, and all decisions can be finalized before construction or renovation begins.

• Realism: Real time rendering has allowed specialists to achieve a new level of highly realistic visualization. The gaming industry as we know it is captivating more and more gamers by offering incredibly realistic visualization of environments and characters, helping them to immerse themselves in another world and enjoy the power of computer graphics.

• Collaboration: Real-time graphics has become a game-changer for collaborative projects, allowing multiple users or teams to work together seamlessly. This technology enables changes made by one user to be instantly visible to others, making it a great option for collaborations with partners and clients. Such effective project collaboration provides new opportunities for creative freedom and guarantees fast and reliable results.

• Great marketing tool: Just like any other type of realistic visualization, real-time computer graphics allow you to showcase the interior, exterior, and surrounding area of a house or apartment that is still under construction. This presents a fantastic opportunity for real estate agents to secure favorable deals before the project is complete. Moreover, this option is also perfect for people who cannot visit the property but are keen on purchasing it. Additionally, such visualizations will be a great addition to the portfolio of designers and architects, as well as companies specializing in high-quality architectural presentations that seek to gain a competitive edge.

• Visibility and accessibility: When it comes to showcasing a designer’s, architect’s, or manufacturer’s concept, 3D rendering in real-time is the ideal method. Compared to intricate diagrams, drawings, or sketches, it offers a much clearer way to convey all the details of the idea. With this approach, you can examine every small detail of the object from all angles and zoom in as necessary. Moreover, such immersive presentations enable clients to experience the ambiance of their potential home or premises and ensure they’re satisfied with everything. Finally, it’s also an effective way to identify and address any issues that may arise.

Thus, real time rendering creates new opportunities for both companies and clients, allowing them to interact and experiment with projects as they are being developed. Real-time 3D rendering is now simultaneously used to create engaging visual stories and to improve the design process.

Real time rendering techniques

There are a few techniques, used in creating real-time graphics:

Ray tracing

Ray tracing is a rendering technique used in computer graphics to create realistic images. It simulates the behavior of light as it interacts with objects in a virtual scene. When using tracing, rays are sent from the camera, which, when they hit an object, are reflected from one surface to another and transfer light to the source. This method imitates the behavior of light in real life and allows simulate many optical effects, including shading, scattering, reflection and refraction, motion blur, depth of field, soft shadows, and indirect lighting. Because it mimics the behavior of physical light (photons), the result is a much more photorealistic image, unlike the rasterization method.

Rasterization

Three-dimensional graphics consist of objects, and they consist of points connected by lines, or polygons. Rasterization is the process of converting all the polygons, i.e. converting the shapes of a 3D scene into a projection on a 2D grid of pixels displayed on the user’s screen (converting vector images or objects into pixel-based raster images). This conversion allows the computer to understand the color, brightness, and other characteristics of individual pixels, making it easier to display images on digital screens. During this process, the computer uses mathematical algorithms to interpolate color between pixels and calculate the position of each pixel in the image grid. The resulting raster image is generally easier to visualize and manipulate than vector graphics, especially when it comes to visual effects such as shading and textures.

This method is much more productive and faster than ray tracing, but it cannot reproduce effects based on reflected light, such as real-world reflections, transparency, and ambient shading.

Shadow mapping

This method involves creating a depth map of the scene (a shadow map) from the light source’s perspective, then using this map to determine which parts of the scene are in shadow and which are illuminated. If a pixel is in shadow, it is painted with a darker color to create the illusion of a shadow cast by the light source. 

Texture mapping

This technique involves overlaying a texture on the surface of a 3D object to add detail and realism to it.

Physically correct rendering

This is a computer graphics method that allows you to display objects more accurately by simulating the behavior of light in real life. It involves the accurate calculation of the physics of light, materials, and their interaction to create realistic images. The methods and algorithms of this rendering are based on physically accurate formulas and use the properties of real materials.

Level of detail (LOD) 

LOD allows a scene to be rendered at different levels of detail depending on the distance between the camera and the object. This can help improve performance by reducing the number of polygons that need to be rendered for distant objects. LOD can also include reducing the number of vertices, simplifying textures, or removing unnecessary elements. The aim is to maintain an attractive appearance for the scene or object, even when represented with less detail, while still ensuring a good frame rate during rendering.

Real-time rendering software

As a company providing top-notch 3D rendering services, we have extensive experience working with various programs. We understand that the 3D visualization and animation industry now boasts a plethora of affordable and high-end solutions. To ensure you make an informed decision, we have curated a list of dependable and well-known real-time rendering software options, highlighting their features to help you choose wisely.

1. Unity

Unity is a popular real-time rendering software used to create 2D, 3D, and virtual reality apps and games. It was first released in 2005 and has since become one of the most widely used game engines in the world. It has a powerful set of tools for creating 3D environments and supports a wide range of platforms.

Unity enables developers to build engaging and visually stunning games that run on a variety of platforms, including Windows, Mac, Android, iOS, PlayStation, Xbox, and others. The software uses a component-based architecture that makes it easy to assemble and modify game objects and scenes.

One of the key features of Unity is the ability to render in real time. The engine uses a direct rendering technique to create realistic lighting and shadows in real time. This allows developers to see changes in the game world as soon as they are made. 

Another great thing about Unity is its extensive resource repository, which offers a vast selection of pre-made resources like 3D models, textures, animations, and sound effects. This feature can be a real-time-saver for developers, allowing them to focus on crafting truly unique and immersive gaming experiences.

2. Unreal Engine 

Unreal Engine is another popular real time render engine that is widely used in the entertainment industry. Developed by Epic Games, it offers advanced graphics capabilities and supports several platforms. It contains an advanced set of tools for fine-tuning and customizing textures, animations, skins, interactions between characters, etc.

Unreal Engine, just like Unity, has the ability to render scenes in real-time. This is made possible by utilizing Physics-Based Rendering (PBR), which ensures that materials and lighting behave in a physically accurate way, resulting in more realistic scenes. Unreal Engine offers a wide range of options for creating photorealistic 3D graphics, with numerous textures, visual effects, and materials that can be applied to objects to alter their appearance. The graphics are highly customizable, allowing you to create any type of materials, surfaces, and effects, and set different parameters for them, which can then be mixed together. Additionally, using the internal Cascade tool, this real-time rendering software enables you to create fine particles such as dust, rain, snow, and more, that look incredibly realistic and move dynamically.

Unreal Engine is becoming increasingly used in architectural visualization, film, television, VR, and AR. The real-time render engine is also used on television: it allows you to apply effects to live video.

3. Twinmotion

Twinmotion is a real-time 3D rendering software developed by Epic Games, the same company behind the Unreal Engine. Although Twinmotion is based on Unreal Engine technology, it is a standalone application that allows users to create a high-quality real-time rendering of architectural and interior projects. Working with Twinmotion, you can get highly detailed renders at any stage of the project, not just the final stage.

Twinmotion has an intuitive interface that makes it easy to navigate and use, even for beginners. With the real time render engine, users have access to a vast collection of 3D models, textures, and materials that can be used to bring their scenes to life. This library includes lighting sources, people, vehicles, plants, and even sounds to enhance the overall experience. Thanks to light and weather effects, you can create realistic and atmospheric scenes.

When it comes to rendering speed, users will be pleasantly surprised by how quickly they can obtain high-quality images, videos, and 360° panoramas in this software – it only takes a matter of seconds. Additionally, the program allows you to select which camera renders you want to receive at the moment. With Twinmotion, it’s possible to set up multiple cameras within a single scene, offering different views of both the project’s exterior and interior.

With just one click, you can synchronize scenes using the software with ArchiCAD, Revit, Rhino, SketchUp Pro, Vectorworks, SOLIDWORKS, BricsCAD, and RIKCAD. Additionally, the software supports various file formats and is integrated with Unreal Engine. Real-time work allows you to eliminate the wait for rendering changes to zero. For an even more realistic experience, you can easily switch to virtual reality mode.

4. Enscape

Enscape is an exceptional real-time rendering and virtual reality program that empowers architects, designers, and engineers to visualize and present their 3D models in an incredibly realistic and immersive way. Enscape also serves as a plug-in for various 3D modeling software such as SketchUp, Revit, Vectorworks, Rhino, and ArchiCAD. It connects directly to these programs, providing an integrated visualization and design workflow. Thanks to this and the Instant Rendering feature, all changes made in Revit, for example, are instantly reflected in Enscape.

With Enscape, you can create real-time walkthroughs, 360° panoramas, and virtual reality. The program supports a range of lighting and material options, allowing users to create highly realistic and detailed visualizations. Enscape also offers a comprehensive library of assets. So, you can use ready-made 3D models or import your models into Enscape.

You can find Enscape to be incredibly user-friendly, as it lets you work intuitively with a renderer that is accessible to everyone. You don’t need any specialized knowledge to use it, and it’s the quickest and simplest method for transforming your models into immersive 3D objects.

5. Chaos Vantage

And last but not least – Chaos Vantage, which is a great software for creating stunning visual effects and animations. It’s relatively new on the market, and it comes from the creator of Corona and V-Ray. With Chaos Vantage, you can make changes to a scene in real-time and see the results immediately without the need for time-consuming pre-rendering. The application provides tools for animating objects in three-dimensional space, adjusting light, using shaders, and post-processing images. It also offers users tools for dynamic animation, including parameters such as speed, acceleration, trajectory, force, and more. The interface is simple and easy to use, so you can create effects quickly and effortlessly.

With Chaos Vantage, you can achieve the most realistic results in complex 3D scenes thanks to its real-time ray tracing technique. It offers a seamless connection with other programs like 3ds Max and Rhino, making importing all resources a simple one-click process. Once the project is transferred to Vantage, all changes are reflected instantly without the need to customize materials, lighting, or other options. 

In addition to navigating the scene, you can select the camera’s location in the scene for offline V-Ray rendering and preview your animations. The application also allows you to make simple changes like moving, duplicating, transforming, deleting, or hiding objects. 

Chaos Vantage has a variety of tools and features like support for various plug-ins, tools for working with color, creating and transforming objects, and working with speed. It’s fully customizable and compatible with Windows, Mac, and Linux, making it ideal for various 3D animation projects. The application comes with a vast library of scripts to simplify your work. Chaos Vantage requires an NVIDIA RTX series graphics processor.

There are numerous software for real-time rendering, each with its own features and possibilities. Based on our experience and market demand, we’ve selected a few of the best programs to recommend. However, we encourage you to consider your hardware’s capabilities when choosing a program that suits your needs. Alternatively, you can try various options to determine which one works best for your project and needs.

You can find out more about these programs in our blog post “Best 3D rendering software in 2023”

Challenges in real time rendering

When considering working with real-time 3D rendering, it’s important to keep in mind that while it has many benefits, there are also certain aspects that require attention. For instance, real-time rendering involves complex calculations of geometric transformations, shading, and lighting that must be performed quickly, which can require a significant amount of resources to be optimally effective. Achieving realistic graphics also requires pushing the limits of available software and hardware resources, and real-time graphics heavily rely on GPUs to perform computations quickly. However, not all systems have powerful GPUs, so creators must optimize rendering methods to work on different platforms with different capabilities.

Real-time computer graphics also requires a certain amount of skill and can be more challenging than pre-rendering. Specialists often have to use techniques such as detail level management, occlusion filtering, and frustum filtering to optimize the amount of geometry and effects rendered in each frame. On top of that, a lot of control is handed over to the client, and in industries like architecture or design, where control is often essential, handing over that control to someone who may not understand design on a fundamental or even superficial level can have serious consequences. 

Conclusion

Real-time rendering has undoubtedly become a crucial part of the modern technology landscape. It has completely revolutionized the way we experience and engage with digital content. As technologies have advanced, real-time rendering has become increasingly sophisticated, enabling the creation of visually stunning graphics, immersive environments, and seamless animations. 

From video games and virtual reality to architectural visualization and product design, real-time rendering has expanded the creative possibilities of artists, designers, and developers. It has allowed them to bring their ideas to life quickly, efficiently, and with an unprecedented level of detail and accuracy.

Moreover, real time rendering has the potential to transform many industries, from healthcare and education to entertainment and advertising. It can increase the effectiveness of medical simulations, improve the educational process, and create more engaging marketing content.

In this article, we’ve delved into the world of real-time rendering – what it is, how it works, the various techniques involved, and its main advantages. Additionally, we’ve provided a list of the top real-time rendering software and explored the industries where this technique is most commonly used. Finally, we’ve touched upon some of the challenges you may encounter if you choose to learn this type of rendering. We hope you found this information insightful, and we invite you to stay tuned for more fascinating insights into 3D rendering. Feel free to share your thoughts with us in the comments section.