In this article, I’ll explain in simple terms what’s behind the 3D animation you watch in movies and what makes it different from conventional two-dimensional animation.
What is that extra 3rd dimension? Take a piece of paper and sketch a simple figure on it (a cat, a dog, or whatever comes to mind). Let’s say it’s a cat and it’s looking at you from that sheet of paper. So you have the front view of the cat in front of you. Suppose you feel you want to see the cat from one side. Does it help if you flip or flip the paper? No why? It’s simply because the sketch you drew is missing the 3rd dimension.
Every object in the real world that you see around you has the 3rd dimension, and that is why you can take it and rotate it to see it from different angles. The sketch you drew had a length and a width, since the paper you drew on also had a length and a width. But it lacks a thickness (3rd dimension) and that’s why your sketch didn’t have that extra dimension.
Assume that instead of sketching your fantasy on paper, you decided to sculpt it out of a handful of clay. Since the medium you used (clay) had volume, you had to define the cat’s shape from all angles when sculpting. Hence, you unconsciously added that 3rd dimension to it, and that is the reason you have the freedom to run it however you want. How does
conventional 2D animation work?
Before computers started playing their indispensable role in the animation industry, everything was done manually by animators, who were essentially artists. They would create a series of slides with images on them, with each slide image being the continuation of the previous one in the series. For example, if an animator wanted to simulate a falling ball, they would create a series of slides with the first slide showing the ball at the top. The next slide shows the ball. It may be 1 cm lower than the one on the first slide. In the next lower again, and so on, until the last slide shows the ball hitting the ground. When the entire series of slides is shown in front of the viewer at a fast pace, the feeling is created that the ball is falling down.
The whole process was tedious and time-consuming. When computers came into play, frame redrawing was minimised because copying and pasting duplicate elements between successive frames was very easy with computer help. The artist only needs to make the necessary changes that should exist between successive frames. As technology progressed, software evolved that again minimised the work of a 2D animator, in such a way that several things started to become automated. Motion tweening and other techniques let an animator set an object’s start and finish positions and shapes, then let the computer do the work of making the intermediate frames.
What was missing in 2D animation?
Because all real landscapes and objects are 3D, and when converted to 2D, they lose their reality, 2D animation has always missed the essentials.Later, cartoons started to simulate the 3D effect by using gradients and different highlights, but it required a huge extra effort on the part of the artist.
How 3D graphics work:
The stages in 3D animation are more numerous as compared to 2D animation. The first part of 3D animation starts with character sketching and 3D modeling. In the next stage, the characters are rigged for animation. In the next stage, they are animated. This is actually too compact a form of what happens in the background. Let’s look at each of them in a little detail.
Character Sketching: This is the stage where an artist sketches what the character should look like from different angles. Typically, the sketch is created on paper or canvas.Because many variations of poses are made, it would help the 3D modeller to make a 3D model of it.
Character Design:A 3D artist, who specialises in a 3D modelling and animation tool, will examine the sketches and begin sculpting the figure using his imagination and skills. I used the word “sculpt” because the process is very similar to the real sculpting we do with raw materials like clay. The software tool that the artist uses offers several approaches to perform the modeling. Commonly, organic modelling techniques such as polygonal modelling (a polygon is subdivided to get the desired shape), NURBS modelling (curves are arranged to create a surface that flows through it), and subdivisional modelling (a hybrid mixture between polygonal modelling and NURBS modeling)
The 3D model finally obtained will be in an editable form, and the model will depend on the approach used. For example, a NURBS technique will yield a 3D model in the NURBS view (curves and surfaces). Once the modelling is complete, the artist converts it into the basic polygonal mesh (vertices only). The polygonal mesh is nothing but a huge number of polygons arranged in such a way that they make up the entire character. This change to a polygonal mesh has a lot of benefits, like faster rendering speed and compatibility with a lot of different programs.
Scene construction: In addition to the characters, the animation will contain an environment and related objects. 3D modelling software provides methods to simulate the environment, model the world, the sun, etc. For example, in the 3D modelling and animation software called Maya, the artist has a huge library of paint effects that include trees, leaves, etc., from which he can drag and drop to a scene and modify it according to his needs.
Texturing: During this phase, all objects in the scene are given appropriate textures using the specific facilities of the 3D animation tools. Some tools only provide facilities for mapping an image texture onto the 3D model, while more advanced tools even let you paint on the 3D mesh texture surface.
Lighting and camera setup:
This process is very similar to that of real-world movie making. The 3D animation software provides different types of lights that you can position in the scene in any direction you want. You can adjust the intensity, the cone angle, or even the shade of the individual lamps. The camera is also a replica of the real camera we use for shooting. We can place multiple cameras in a scene and adjust the focal length, aperture, and almost every other parameter you would find in a real camera.
once the static elements are set, the 3D artist applies motion to them. This process, called animation, is performed by setting keyframes. To animate a falling ball, the animator would set the first keyframe to 0 seconds with the ball at its original top position. He would set the next key to, say, the 5th second, with the position of the balls touching the ground. The 3D animation software interpolates the falling action of the balls between the 0th and 5th second. The animator can adjust the interpolation behaviour using graphs or by setting intermediate keys.
Similar principles are applied in character animation. The skeleton is animated by the animator, and the 3D mesh skinned on the skeleton is automatically animated. Character animation is often supported by plug-in tools (e.g. bipedal) specifically made for creating character animation sequences such as walking or running. The various scene elements, cameras, and lights are animated using basic key-frame animation, based on the requirements of the storyboard.
Once the scenes are animated, they go through a process called rendering, where the 3D rendering is converted to a video format that can be read and edited with professional video editing software.
Edit and mix:
The rendered scenes are imported into video editing software and edited. In the case of movies where human characters have to interact with animated characters, mixing is done well at this stage, although the creation of 3D scenes would have been done for that purpose, using techniques such as motion tracking.
The advantages of 3D animation
You may have wondered why we should go for 3D animation when the whole process itself has a number of stages and turns out to be very complex. Apart from the complexity involved, it also offers many advantages. Once the modelling process is complete, the 3D software offers very flexible control over the scene and animation. You can rotate the model to any angle you want (unlike in 2D). 3D animation software also provides a rich collection of tools that support the process of modelling and animation. You can choose from a wide variety of modelling techniques based on your needs. The lighting and camera settings are the exact replicas of a real movie environment. Apart from all this,