In this blog post, we will examine the role and importance of modeling and rendering techniques in maximizing realism in 3D animation and analyze how they enhance visual perfection.
Recent 3D animations give the impression of being filmed in real life thanks to their detailed three-dimensional images. This realism goes beyond simple technological advances and plays a major role in providing viewers with a more immersive visual experience. For example, even the facial expressions of characters in animations can be expressed vividly, giving viewers the illusion that they are seeing real people in front of them, rather than simply watching a video.
Unlike displaying natural images captured from real objects on a screen, creating and outputting 3D composite images requires two main processes: modeling and rendering. Modeling is the process of setting or modifying unique values related to the shape, size, spatial position, and surface characteristics of objects in a three-dimensional virtual space. This process is similar to a digital sculptor working with clay, using digital tools to adjust the shape of an object and give it detailed characteristics.
When setting the shape and size, triangles, which are usually formed by three vertices, are used. This method expresses the surface of an object as a net made up of small triangles. This method can be used to accurately express even surfaces with complex curves. The vertices of the triangles determine the shape and size of the object. The number of vertices remains unchanged even if the object is transformed, and the relative positions of the vertices remain unchanged as long as the shape of the object remains unchanged. When the object becomes larger or smaller, the distance between the vertices becomes wider or narrower.
When an object rotates or moves, the vertices rotate around the axis of rotation while maintaining the same distance between each other, or move in the same direction by the same distance. This sophisticated modeling process is essential not only for defining the basic structure of an object, but also for subsequent processes such as texturing and applying lighting effects. Each triangle that makes up the surface of an object is assigned a surface property that represents its unique color, texture, and other characteristics. These surface characteristics play an important role in vividly expressing the texture of objects. For example, defining these detailed surface characteristics is essential for realistically rendering the gloss of a metal surface or the texture of wood. Rendering is the process of creating a two-dimensional image based on the observation point, which indicates where the object is viewed from, using this data, which is information about three-dimensional objects in space.
The rendering process goes beyond simply creating images, aiming to produce more realistic scenes by taking into account the interaction of light, the position of shadows, and the effects of various light sources. The entire screen is divided into small dots called pixels, and the screen is displayed with a fixed number of pixels, with each pixel assigned a value representing its brightness, color, and other characteristics. In the rendering stage, the principle that objects appear smaller when they are farther away and larger when they are closer is used to specify the color values, thereby creating a sense of perspective. Based on values that represent surface characteristics, color values are determined by considering factors such as shadows and lighting that are created on the surface of objects due to being blocked by other objects, thereby creating a sense of three-dimensionality.
Through this sophisticated rendering process, all elements on the screen blend together naturally, giving viewers the impression that they are actually in that space. Once the shading values for all pixels that make up the screen are determined, a single frame is created. When this is displayed on a monitor via a display device, a still image is completed. Repeating modeling and rendering to create frames and displaying them in order results in a video. The video expresses vivid movements as the frames are switched so quickly that they are invisible to the naked eye. In this process, the position and size of objects and changes in lighting are calculated for each frame to achieve more natural and fluid movements. When creating a frame, after completing the calculations related to modeling, the results are used to perform calculations for rendering. At this point, the more vertices there are, the higher the resolution, and the more output pixels there are, the more calculations are required, which increases the calculation time. This means that the higher the image quality, the more calculations are required, and high-performance computer equipment and efficient calculation algorithms are essential for producing high-quality animations. The central processing unit (CPU) of a computer performs data calculations one by one in order.
Therefore, when an excessive amount of data is concentrated, a bottleneck occurs where data that has not been processed waits in line, causing frames to take a long time to complete. For this reason, various techniques are used in the animation production process to minimize bottlenecks. For example, complex calculations can be processed in advance, or the calculation process can be divided into multiple steps and distributed for processing.
Graphics processing units (GPUs), developed to complement the graphics processing capabilities of CPUs, are devices that can perform data processing, including calculations, independently. GPUs are equipped with thousands of cores, enabling large-scale parallel processing. Each core of a GPU can only perform calculations specialized for graphics and calculates at a slower speed than CPU cores. However, when the same calculation must be performed multiple times, GPUs can generate output images at high speeds. This is because GPUs transmit the data used in a single calculation to each core sequentially, and then transmit a single calculation command to all cores, allowing each core to calculate all data simultaneously, thereby shortening the calculation time. Thanks to this high-speed processing, complex visual effects in 3D animation can be realized in real time, delivering smoother and more vivid images to the audience.
