Introduction
Animations with resounding graphics, virtual reality, and the ability to control a character and its environment. Sounds like a video game, right? What if I told you that this technology has profound uses apart from gaming? But first, let us understand the science behind those animations.
Real time rendering is the process through which animations are rendered so quickly that they appear to be generated in absolute real time. A sub field of computer graphics, it is focused on producing and analyzing real time images. The images are produced using either a coarse description or an analogous model which helps your software analyze the same and produce renders using Graphics Processing Unit (GPU).
For a human eye to perceive things as natural, the image or animation must be between 30 frames per second (fps) to 60 fps. Advancement in technologies has resulted in programs rendering animations in less than 30 fps.
Difference between real and non-real time rendering
The main rationale behind real time rendering is to ensure interactivity. As a user or controller, one interacts with virtual reality in real time. Therefore, the scene composed of multitude of images must be calculated instantaneously just before being displayed on the screen, for the user to perceive it as real time.
Nonreal time rendering refers to one where the animations are created using high quality graphics. As the name suggests, everything is calculated beforehand.
Although the holistic motive behind both is to enhance visualization, the rendering time makes all the difference, resulting in differentiated applications.
Real time rendering has found profound uses in video games, whilst non real time rendering is used in cinema, where high quality renders close to reality are created.
Techniques of real time rendering
There are two techniques which have gained popularity in rendering.
- Ray tracing
- Rasterization
Let us delve deeper into each of these techniques.
Ray Tracing
The basic premise behind this method is to create an equivalent mechanism of how light behaves in the real world onto a virtual scenario. Rays of light from a light source (consisting of photons) are reflected when they bounce of a surface or are refracted when they absorb in a transparent surface.
Similarly, ray tracing technique involves tracing the virtual (simulated) light source by tracking virtual photons (millions of them!) through GPU. The number of photons that the GPU calculates is directly proportional to the brightness of the virtual light source.
This process, which mirrors reality, offers a major advantage in terms of the accuracy of depiction of the image. Through ray tracing, shadows are made more dynamic and realistic looking, with softer edges and greater definition.
Since millions of photons are to be tracked and calculations need to be done to depict the accuracy as per description, the processing speed of the GPU must be high, resulting in a capital-intensive setup which many organizations would not want to invest in.
To portray a level of accuracy which seems natural to the human eye, ray tracing takes a lot more time than rasterization, another technique of rendering which we will discuss next.
Rasterization
In this technique, the image is described in vector graphics format, i.e., on the 3D (x,y,z) plane, which further is converted onto a raster image, which, in turn, is an image made entirely of pixels. A common method is of triangle rasterization.
Digital 3D models are represented as polygons, which are broken into triangles before the rasterization process. This creates a model of 3D triangles, ensuring that, adjacent triangles leave no holes between them, and no pixel is rasterized more than once, i.e., the rasterized triangles do not overlap.
To ensure the above criteria, rasterization rules are applied, one of those roles being the top left rule which states that a pixel is rasterized only if its center lies
- completely inside the triangle
- exactly on the triangle edge
The quality of rasterization is further improved through antialiasing, a method through which smooth edges are created, thereby improving the quality, and producing a higher resolution output.
Ray tracing vs rasterization
Rasterization and ray tracing are both techniques of rendering which can be applied as per the requirement of one’s domain. Rasterization has been around for decades now whilst ray tracing was only recently introduced.
Rasterization involves an object-based approach, meaning – each object is colored first and only those pixels are shown which are closest to your eye. On the contrary, ray tracing colors the pixels first and then identify them as an object later.
Rasterization involves special techniques and vector calculations to create realistic visuals. Since this method identifies objects and then converts them to pixels, the logic and rationale behind each object and each scene is to be calculated. Although this may not take much processing power, it involves a lot of efforts from the developer.
Ray tracing is based on light rays completely. The result is based on the calculations of virtual photons hitting a surface and the results being computed according to the same. It involves a lot of processing power from the GPU, especially if one is rendering high resolution output close to reality.
Which technique is preferred?
The hardware advancement decades ago was nothing compared to what we are experiencing today. Affordability also played a major factor due to which rasterization was the preferred technique for rendering. In fact, ray tracing took a lot of time and resources for it be ready for mainstream adoption. Companies like NVIDIA and AMD have recently introduced ray tracing into the gaming arena.
In fact, some companies do use a hybrid of both techniques, rasterizing the object and ray tracing for the shadows to carve out high resolution output.
Applications beyond gaming: Interior Design and Space Management
Architectural visualization has come a long way from being a time and cost intensive process involving days to weeks of creating exhausting 2D designs only to be rejected by the client. Minute changes or amends would take up days to change.
But now, real time rendering has also found applications in interior design, through which one can create, collaborate, and modify a design which can be visualized within seconds across various display systems including extended reality (XR).
Advanced tech start-ups like Tooliqa have already started to leverage this technology for innovative use cases in industries beyond gaming saving immense time and cost. This also fosters better and healthier collaboration between all the stakeholders involved in the process.
Not only that, the necessity of realistic visuals for decision making in industries like interior design makes real-time rendering immensely valuable for reducing the turnaround time for the projects.
Conclusion
The world is developing and growing at an exponential pace, with innovative technologies penetrating existing applications and making the lives of people easier. What is to look out for is real time rendering creating new opportunities in greater realms.
Also read: The Future Of 3D - Above Today and Beyond Tomorrow | Insights - Tooliqa
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