Category: Computer Animation Fundamentals

It was last week’s class, but technically it’s this week’s class, so it’s here.

• Using the UE Mannequin: The UE Mannequin is a standard humanoid skeleton and rig that comes with UE. You can use it as a reference or a template for rigging your own models. You can also import models from external sources, such as Mixamo or Blender, and retarget them to the UE Mannequin skeleton. 
• Using Control Rig: Control Rig is a feature in UE that allows you to create custom rigs and controls for your models using a node-based graph editor. You can use Control Rig to create simple or complex rigs, such as full-body IK, spline rigging, pose caching, and more.
• Using UModeler: UModeler is a plugin for UE that enables you to model, rig, and animate 3D objects directly in UE. You can use UModeler to create low-poly or high-poly models, and rig them with bones, joints, and constraints. 

With the models and terrain creation tools in the UE model library, you have everything you need to make a scene quickly. The problem with character controller binding that we had last week is solved now, and you can achieve better animations.

I wanted the art to be weathered and discarded in the unknown canyon, but the actual effect was not so good…… But in addition to the functionality of UE itself, there are other plugins that work well throughout the process.

• Quixel Megascans: A library of high-quality 3D scans of real-world objects and surfaces that you can import and use in your UE projects. Quixel Megascans can add a lot of detail and realism to your scenes, especially for natural elements like rocks, plants, and water.
• Path Tracing / Ray Tracing: A rendering method that simulates the behavior of light rays in a scene, producing accurate reflections, shadows, and global illumination. Path tracing and ray tracing can greatly enhance the realism and quality of your scenes, but they also require more computational power and optimization.
• HDRI Maps: High dynamic range images that capture the lighting and color information of a real-world location. You can use HDRI maps as backdrops and light sources for your scenes, creating a consistent and realistic mood and atmosphere.
• Physically-Based Materials: A material system that uses realistic parameters and properties to define how a surface looks and interacts with light. 

Grease Pencil Tool

With the Grease Pencil tool in Maya, you can sketch in two dimensions on the monitor. You can use it to draw the poses and paths of the motion, and to show how the tail moves according to the object’s motion curve. This can help you understand the movement better.

Be Careful! You also need to pay attention to the model’s shape and balance, and adjust the center of gravity and dynamics accordingly, so that the model does not look like it is going through itself.

Now that the terrain shape is complete, we need to add some materials to make it more like the real world. But before that, first set up the folder, will create the content and migrate it into the project. Start by creating a new folder called Landscape in the Content folder of your project.

Then create the following three folders in the Landscape folder:

material

ASSETS

texture

In 3D animation, the motion of one part can affect the motion of other parts, creating a follow-through and overlapping action. This means that some parts will lag and overlap with the main motion, resulting in a smooth and natural effect. Follow-through and overlapping action can be shown in these ways:

• The motion of accessories: For example, long hair, tail, cape, etc. These parts will keep moving after the main motion stops, creating an effect of inertia and elasticity. This effect can be achieved by changing the position and angle of the accessories in each frame, or by using hair and cloth systems in animation software.
• The motion of the body: For example, waist, arms, head, etc. These parts will stretch and squash each other when the main motion happens, creating an effect of force transfer and rhythm. This effect can be learned by watching videos or pictures of real people or other characters, or by using skeleton and muscle systems in animation software.

• Create a Lens File Asset that stores the distortion and nodal offset data for your camera and lens combination. You can do this by right-clicking in the Content Browser and choosing Miscellaneous > Lens File, then double-clicking the asset to open the Lens File Asset Editor. You need to fill in the lens information, such as the lens model name, serial number, sensor dimensions, and lens model. You also need to set the camera and media source under the viewport settings. For more details, see Camera Lens Calibration Quick Start Guide or Camera Lens Calibration Quick Start for Unreal Engine.
• Add a Live Link Controller Component to your CineCamera Actor and set the Lens File Picker to the Lens File Asset you created. This will allow you to control the camera parameters and lens distortion through Live Link data from your physical camera and lens. You also need to set up Live Link Source that provides the camera tracking and focus, iris, zoom (FIZ) data, such as Livelink Source or Livelink Blueprint Virtual Subjects.
• Create a Lens Distortion Component and add it to your CineCamera Actor. This will apply the lens distortion from the Lens File Asset to your camera view. You can adjust the distortion scale and the overscan factor to fine-tune the distortion effect.
• Create a Lens Settings Asset that stores the aperture, focal length, and focus distance for your camera and lens combination. You can do this by right-clicking in the Content Browser and choosing Miscellaneous > Lens Settings, then double-clicking the asset to open the Lens Settings Asset Editor. You need to fill in the lens settings, such as the minimum and maximum aperture, focal length, and focus distance, as well as the focus method and focus smoothing. You also need to set the camera and media source under the viewport settings. For more details.
• Add a Lens Settings Component to your CineCamera Actor and set the Lens Settings Asset to the Lens Settings Asset you created. This will allow you to control the aperture, focal length, and focus distance of your camera through Live Link data from your physical camera and lens. You can also enable the depth of field effect and adjust the bokeh shape and size. For more details, see.

To create 3D animation, one can apply the general principles that emerged from the development of animation. However, these principles alone are not enough. One also needs to use realistic video references for animation and master the process of using these knowledge skillfully.

For the UE project, we have redesigned the scene map. The next step is to create models based on the model assets.

One way to improve the animation quality is to make the motion more fluid. The ball animation can be more engaging by adding variations like squashing and stretching the ball. These variations are subtle and last for only a few frames, but they make a significant difference in the outcome.

Revisiting the animation survival kit, employing Overlap in animation can boost the cartoon action effects. Nevertheless, like every animation, each frame should be exact and authentic, because the works cannot deceive the spectators.

To make a material, you need to create one in the Content browser and open it in the Material Editor. There, you can use nodes to set up your material’s properties and effects. You can drag and drop things like textures, constants, and functions from the Content browser to the material graph, or right-click and search for nodes you want. You need to link nodes to the right slots of the material output node, such as base color, metallicity, roughness, normal, etc.

We will learn about how to adjust the camera settings in the next lesson. To help me prepare, I have gathered some useful documents on how to operate the camera.

使用摄像机 | 虚幻引擎文档 (unrealengine.com)

使用虚幻引擎摄像机 | 虚幻引擎5.1文档 (unrealengine.com)

Summarize what I learned：
First, you need to design your hair style (groom) in digital content creation (DCC) software, such as Maya or Houdini. Then, you need to export your groom as an Alembic file, which is a familiar format for exchanging 3D data.
Next, you need to open Unreal Engine and activate the plugins and settings related to hair rendering and simulation. After that, you can import your Alembic file as a Groom asset, which is a special type of asset that stores hair data.
Then, you need to edit your Groom asset in the Groom Asset editor. Here, you can apply varied materials to your hair, adjust the level of detail for different distances, enable and tweak the physical properties of your hair, and debug your hair using various view modes.

Adding a relevant URL in case I need it.

• 虚幻引擎毛发渲染 | 虚幻引擎5.3文档 (unrealengine.com)