Are you new to creating three-dimensional (3D) models? Do you want to understand how to create these models? Then you have come to the right place. This article will give you a step-by-step understanding of how to make a 3D model.
What is a 3D model?
A 3D model is a three-dimensional representation of an object, surface, or environment. It means that you can see three dimensions of the object, namely its height, width, and depth. In computer graphics, specialized software is used to make these models. This process is called 3D modeling. Here, a collection of points connect to form triangles, curved surfaces, lines, etc., and form a 3D model.
Now that you understand what a 3D model is, let’s learn how to make one.
How to make a 3D model using various methods?
Professionals use different methods to make 3D models. One method is to make them from scratch using 3D modeling software. Another method is turning real-world objects into models through 3D scanning and photogrammetry. In this section, we will look at each of these techniques. But first, let’s start with the basics and learn some important terms and concepts.
3D model components
- Vertex: This is a single point. It is the smallest part of a 3D model.
- Edge: Two vertices connected by a straight line become an edge. It defines the shape of your model.
- Polygon: This refers to any shape formed by connecting the vertices with straight lines. The most common polygon shapes are quads (four-sided polygons) and triangles.
- Mesh: It is a cluster of polygons connected along their edges. One or more meshes can constitute a 3D object.
- Face: It refers to the space between edges. It is a single polygon that makes up a mesh.
3D environment components
- Vector: It refers to the direction and orientation of a 3D environment. It uses three axes: the X axis, the Y axis, and the Z axis.
- Plane: It is a two-dimensional surface on one of the three axes mentioned above.
Vectors and planes make 3D environments navigable in all 3D modeling software.
Different methods of creating 3D models
3D modeling techniques using software
In this method, an artist can create three-dimensional models from scratch using 3D modeling software. This method gives artists the flexibility to create something that doesn’t exist. It is a great method for those who create design products, mechanical parts, and 3D characters.
It is also useful to those who make three-dimensional replicas of existing objects. This method is used when artists can’t use 3D scanning or photogrammetry. Like designing a historical building located in a foreign country, for example. They turn references like videos and 2D images into a 3D model.
Below are the various modeling techniques:
- Wireframe modeling: This is one of the easiest methods to make a 3D model from scratch. Here, you bend “wires” along the edges of an object to create a three-dimensional structure. These objects consist of points, arcs, lines, curves, and circles. Triangles are the basic elements of a wireframe model. A model that has more triangles looks more realistic.
- Surface modeling: It is a mathematical method of modeling used to display solid objects. Here, the artist focuses on the external parts of the model (or the surface) so the object only appears solid. The aim here is to allow viewers to look at specific angles or solid surfaces of an object. It is usually used in architectural illustrations and video game animations.
- Solid modeling: As the name suggests, it makes solid shapes. It is a complex method as the artist focuses on the internal and external parts of the three-dimensional object. The aim is to ensure that the models are geometrically accurate. It is useful when designing, animating, and visualizing functional models. Like creating machine parts, engines, or automobiles, for example.
- Polygonal modeling: This technique is popular for making games and movies. It is driven by concepts rather than measurements. Here, you create a model by representing surfaces with polygon meshes. You can alter the object’s shape by changing the coordinates of its vertices. Artists use polygonal modeling to create 3D characters and other 3D assets (weapons, vehicles, armor, etc.).
- Digital sculpting: Artists use this technique to create hyper-realistic objects or characters. The end product usually has organic and smooth shapes. This technique is best suited for making video games and animated movies. Digital sculpting is also used for creating prototype models for 3D printing. This process is like the sculpting process in the real world, where a sculpture is made from stone or clay. 3D sculpting requires high artistic skills and specialized software.
The software typically has brush-like tools that help manipulate polygonal meshes. You can pull, push, or twist different parts of an object’s geometry to mimic an organic structure.
This is a very time-consuming process. So, to make a sculpture, one artist makes a polygon model and sends it to a 3D sculptor.
- Box modeling: It is a quick and efficient technique. Box modeling is popular with beginners as it is an organized and structured way to create detailed models. In this technique, an artist makes a model by starting with a primitive shape (cube, sphere, etc.). Large portions or entire objects are manipulated to make a basic model. The artist continues to work on the basic shape till they reach the final model.
- NURBS: It stands for non-uniform rational basis spline. NURBS is an advanced 3D modeling technique that can create complex shapes. Here, complex mathematical equations make realistic shapes from 2D lines. It is like the polygon modeling process. But, the major difference lies in how the software calculates the meshes. Also, NURBS models are more flexible, efficient, and precise.
- NURMS: It stands for non-uniform rational mesh smooth. It is also known as the subdivision surface technique. Here, you start with a base mesh. Then, a single surface is divided into regions so you can use a single surface to create complex shapes. Dividing the surface into subdivisions gives you greater control to make fine details. This technique is used to smoothen poly meshes and allows you to create intricate objects like human hands. It essentially turns a low-poly mesh into a high-poly mesh.
You don’t have to create 3D models from scratch with this method. With 3D scanning, you can create an accurate digital representation with a scanner in real time. You can combine it with polygonal modeling or sculpting to get highly realistic models. In sports gaming, for example, artists scan famous athletes’ faces, so their 3D characters look as realistic as possible.
The scanning process varies depending on the scanner’s technology. Here are some types of 3D scanners:
- Laser-based scanners: These scanners use trigonometric triangulation to scan an object. They project millions of laser beams onto an object. Sensors placed at fixed distances then record the reflections. Once scanned, the object is represented as a 3D structure made of millions of points.
- Structured light scanners: Although these scanners are called white light scanners, most use blue or white LED lights. The scanner uses light patterns to project a geometric shape onto the object. The edge of the pattern is used to determine the object’s shape. These scanners are typically used to get external dimensions.
- Medium and long-range scanners: The scanners rotate 360 degrees to capture millions of points as a mirror spins to redirect a laser toward an object or area. This technology makes it easy to scan large areas or objects. They are great for scanning large objects like planes, buildings, etc.
- Arm-based scanners: These are highly portable scanners attached to an arm. The software tracks the joint movements to know where they are in 3D space at all times.
- Short-range scanners: These scanners use laser triangulation or structured light technology to scan objects.
This method is similar to 3D scanning in that a real-world object is converted into a model. Here, professionals arrange many cameras around an object to photograph it from different angles. They may even use a single camera to take multiple pictures if the object is small enough. Then, they make a 3D model with the photos by “stitching” them together. Computer software typically handles this step of the process.
Photogrammetry is best when you need a 3D model of large objects or landscapes. For example, buildings, college campuses, or a park. Basically, things that are too big for 3D scanning. Photogrammetry also helps you create digital representations with high-quality textures.
However, this technique has a few downsides. Firstly, it is a time-consuming method. Secondly, it doesn’t build a model in real time. The images need to be combined to make the model. It means you can only tell if something has gone wrong after processing the images. Therefore, combining 3D scanning and photogrammetry is recommended for the best results.
The best way to learn how to make a 3D model is to start with a simple project. Decide what you want to create, what you want it to do, and which software is best for your project.
This article has covered some basic concepts of modeling in three-dimensional space. We reviewed the important terms used for the parts of a 3D model and went through the terms used for 3D environments. We also helped you understand how to create an object’s digital representation.
Now, it should be easier to choose your next step and work towards becoming a skilled 3D modeler. Happy modeling!