How Surface Normal is Useful?
Because a surface normal vector tells a lot about the object’s geometry and by geometry, I mean all the intricate details of the object. For example, a normal map of a brick wall can tell us about all the intricate details, gaps, bumps, crevices, and cracks on it. The higher the resolution of the normal map the more details it shows. Now you may wonder how does computer uses those normal maps. When a 3D model is viewed in the computer under a light source, the software simulates light rays from the light source which hit the model and reflect away. When these rays hit the camera the model is visible to the screen (similar to how our eyes see real-world objects). Now when there are more polygons, more light rays are required to render the model, making the calculation very complex and time-consuming.
But if we use the normal maps we can utilize the surface normal vector data in it, so we can re-create a more detailed look with a low polygon model as if it were a detailed model. Normal mapping modifies the way light interacts with the model to create a more detailed look without modifying the underlying geometry. Thus, they can simulate minute surface details such as crevices, bumps, scratches, wrinkles, cracks, gaps and so on. Normal maps are computationally less intensive than polygons. Due to this, they are widely used in 3D software and video games.
This is a normal 3D model with very less polygons, you can see at the edges that the model is plain. This is an example of a model with a low amount of polygons.
low polygon model
This is a 3D model with a high amount of polygons. Look at the edges and see that it is in the shape of the rocks the, same as the texture image. However, this model requires a lot of computation.
high polygon model
This is the same as the first model but with normal maps. You can see the details that normal maps show. The shadows and minute details make it look more realistic. If you look at the edges, they are not bumpy like the second one. This denotes that normal maps only create an illusion without modifying the underlying geometry.
a model with normal mapping
Normal Mapping in Computer Graphics
Computer Graphics has improved a lot in recent years. Nowadays it is much more realistic whether it is animated 3D videos or games. However, rendering such graphics with great detail can be quite hardware-intensive. That’s where normal mapping comes into the picture. It is a technique in computer graphics that uses mathematical computations to create detailed and realistic graphics without using extra polygons. It is a popular method for optimizing the rendering of computer graphics and adding details to it simultaneously. This technique uses something called normal maps which is a 2D image that contains information about the normals of the 3D object. In this article, we will look at what exactly is normal mapping.