Character animation and rigging

What is rigging and how does it work?

Rigging is the process of equipping a finished 3D model with a virtual skeleton, in which all the connected bones are in a parent-child relationship, which greatly simplifies the animation process. For example, if a character moves his shoulder, his forearm and hand bones will also move.

To adjust the interaction of the 3D model with the skeleton, the designer manually sets the weight of each bone. The heavier the bone, the more it affects part of the mesh, so it is important to distribute the load correctly at this stage.

When developing large-scale games and videos, it often happens that some characters have the same structure. Therefore, to save time, such skeletons can be copied and assigned to a new mesh. After equipping the model with a skeleton, the designer adds inverse kinematics to the bones.

This is most often needed for animating arms and legs when talking about a humanoid character, but the technology can also be applied to various body parts of mythical and fictional characters, such as a dragon's tail.

Properly setting up inverse kinematics allows you to keep the model's joints in the correct direction, which makes it easier to create realistic animation.

Then, movement constraints are set on the bones so that they can only move within specified ranges. For example, the model's head should not rotate 360 degrees.

The advantage of rigging is that it gives good control over the deformation of the model, but at the same time it is practically not used for the animation of detailed surfaces. Therefore, to create facial animation, methods that go beyond the usual work with bone structure, such as morphing and blendshapes, are most often used.

Overview of the main technologies used in rigging

A whole stack of technologies is often used to create complex rigging. Let's consider the main ones, which practically no project can do without:

• Joints . The connection points of bones used to control a 3D character model . For example, when rigging an arm, the shoulder, elbow, and wrist joints are added. This allows for the most realistic movement of the limb.
• Controlled keys . These are special elements that activate control of multiple points of the model at once.
• Inverse kinematics. Used to position the character's skeleton as realistically as possible in the space of the game world or animation. The principle of IK is that daughter bones and joints affect the position of the parent bones. For example, moving a character's finger should affect the overall position of the hand.
• Direct Kinematics . This is a type of motion planning in which the model's skeleton does not follow a specific chain of interactions between its elements. This allows the designer to create a variety of realistic poses for the model.
• Morphing . A technique that creates the appearance of one object smoothly transforming into another. As mentioned earlier, this visual effect is most often used when creating complex facial animation.

Levels of 3D character animation

There are 3 levels of 3D character animation. Let's look at how they differ from each other:

Simplified animation

Most often, this type of animation is used during training of specialists, and is used for commercial purposes.

Using simplified animation, you can depict the physics of a process, the functioning of a simple system, etc.

Intermediate level animation

This is a relatively inexpensive animation that is great for solving most presentation and marketing business problems. This 3D animation is characterized by a minimum of complex objects, simple image physics, and simple textures. Despite the fact that the visual series is simplified, the picture has a fairly high-quality appearance.

Photorealistic 3D animation

Animation with a high level of detail, in which every detail and texture is carefully thought out and drawn.

Photorealistic graphics are characterized by:

• many textures;
• the presence of physics of all objects in the frame;
• the presence of skeletal and facial animation of the character;
• working out the physics of liquid objects (if necessary) - reflections, waves, etc.

When creating photorealistic animation, you can overlay real footage onto a 3D render, creating a truly lifelike image. Such characters look vivid and are more memorable to the viewer than others.

Photorealistic 3D animation is widely used in advertising, including television, game development, and animated film creation.

Character animation and rigging at Arionis Games

Developing 3D animation takes a lot of time and this process is not carried out by one person, but by a whole team, where each person is responsible for their own process: designers, animators, screenwriters, etc.

Arionis Games has been developing and animating 3D characters for over 10 years. Our staff consists of qualified employees who can implement animation of any level, depending on the needs of the client's business.