How to use rendering software

Rendering: definition, typology and visualization techniques

Rendering is widely used by planners and businesses: let's see what it is, the types of renderings, and the techniques of visualization

For many years, rendering has been considered best friend" by planners and companies as it has proven to be an excellent communication tool. It helps clients and clients understand design decisions, but it is also a tool for analyzing and controlling the work being produced.

What is rendering

The term rendering defines the Process, which with the help of special software, digital images can be obtained from three-dimensional models. These images are intended to simulate photorealistic environments, materials, lights, objects of a project and a 3D model.

Interior rendering realized with Edificius

It is a computer-generated image that follows three-dimensional modeling based on project data. The generated geometric model is covered with images (textures) and colors that are identical to the real materials, and is then illuminated with light sources that reproduce the natural or artificial light.

For the case in which the parameters are set based on the existing in nature (actual sunlight), HD textures, real perspective recordings, etc. then the rendering can be called photorealistic.

Typologies of rendering

There are two main types of renderings. The difference lies in the speed with which the images are calculated and finalized.

Real time rendering or real time rendering

Real time rendering will mainly used in games and interactive graphics, since images have to be calculated very quickly from 3D information. Therefore, there will be special graphics hardware to ensure fast processing of the images.

Offline rendering

Offline rendering is used in situations where the need for processing speed is lower. Effects work where visual complexity and photorealism are at a very high level. There is no unpredictability, unlike real-time rendering.

Rendering made with Edificius

Rendering: visualization techniques

Z-buffer

One of the simplest algorithms for determining visible surfaces uses two data structures like the Z-buffer (a memory area in which the Z coordinate closest to the observer is stored for each pixel) and the Framebuffer (which contains the color information about the pixels contained in the Z-buffer). The largest Z value is stored for each pixel (assuming that the Z-axis runs from the screen towards the observer's eyes) and at each step the value contained in the Z-buffer is only updated if the point in question, has the larger Z coordinate than the current one in the Z buffer. The technique is applied to one polygon at a time. When scanning a polygon, information about the other polygons is not available.

Scanline

It is one of the oldest methods. It combines the algorithm for determining the visible surfaces with the algorithm for determining the reported shadows. The algorithms that work on the scan line are frame-accurate and get their name from the fact that for each scan line the distances (Intervals) of the visible pixels can be determined. It differs from the Z-Buffer in that it works with one scan line at a time.

Luminous colors in the environment - rendering created with Edificius

Raycasting

Raycasting is able to create a 3D perspective in a 2D map. Raycasting can get a ray from the pixel through the camera and calculate the intersection of all objects in the image. The pixel value is then obtained from the nearest intersection and set as the basis for the projection. An important advantage of ray casting compared to the older scanline algorithm is the ease with which solid or non-flat surfaces such as cones and spheres can be handled. This method is used in the medical field: Computed Tomography (CT), Magnetic resonance imaging (MRI) or Positron emission tomography (PET).

Architectural rendering made with Edificius

Ray tracing

Ray tracing is used to calculate light rays in order to obtain the most realistic possible lighting model with accurate shadows, reflections and indirect light. This is based on the assumption that of all light rays that leave a source, only those contribute to the image that reach the viewer after hitting the object. The light rays can reach the viewer both directly and through interactions with other surfaces. Of course, it is not possible to follow the line of every single ray; but if we reverse the path of the rays and look only at those emanating from the observer's position, we can determine the rays that contribute to the image. That is the idea behind the ray tracing process, which simulates the path of the light radiation back to the viewer.

The popularity of ray tracing forms the basis for one realistic light simulation compared to other rendering models (e.g. scanline or raycasting). Effects like reflection and shadow, which are difficult to simulate using other methods, are the natural result of the algorithm. A relatively simple implementation leads to impressive results, with ray tracing often being the entry point in graphical programming.

Interior rendering made with Edificius

Radiosity

Here is another image-accurate method that further improves the photo-realistic quality of the image because it also takes into account the physical phenomenon of interreflection between objects. In reality, a surface that contains a reflective light component appears not only in our image but also in neighboring surfaces. The reflected light carries information about the objectthat triggered it, especially the color. Thus the shadows are “less black” and the color of the almost well-lit object is perceived, a phenomenon that is often referred to as “color loss”. In a first step, the radiosity algorithm identifies and breaks down the surfaces into smaller components and then distributes the direct light energy. In a second phase, the diffuse energy is calculated, assuming that the surfaces reflect the light in the same way. It also calculates the surfaces that reflect more energy and redistribute it.

 

 

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