UV Mapping UV Mapping is the process of taking the surface of a 3D model and flattening it into a 2D representation in order to apply texturing accurately. Think of it like skinning an object and putting this skin on a canvas so you can paint it’s surface easier. The word UV is actually the co-ordinates that indicate the axes in 2D space which determines the placement of the images on a 3D object. The reason why it’s UV is because it’s the two letters that come before X, Y and Z which are already used for displaying geometry co-ordinates. Creating a UV map is similar to creating a complex puzzle as you have to arrange the pieces of the unwrapped model in a coherent way that the texture artist can understand.
Texturing and Shaders
Once UV mapping is complete, texturing and shading can commence. Even though texturing and shading are two separate processes, they both combine to achieve the model’s overall aesthetic look. Textures are flat images usually created in various image editing software packages like Photoshop for example. Using the UV map from the previous step as guidelines, an artist can accurately apply textures to achieve the look they desire of their model. Texturing isn’t limited to just colour’s however and can achieve photo-realistic qualities with roughness, highlights and translucent effects through the use of multiple maps like diffuse, specular, and bump/normal maps. Diffuse maps is the most basic and necessary map as it applies to the colouring of the texture. Specular maps are generally grayscale images that map out the highlights of an object to emphasize highlights to specific areas of the object, like the white reflection of a characters eye’s for example. Bump or Normal maps add realism to an objects surface as it defines the bumps, scratches and graininess. Without Bump maps objects like a brick or tree wouldn’t look convincing at all as the light wouldn’t reflect off their surface realistically.
A shader is a vital component of a 3D asset as it informs the renderer of how the model’s surface should interact with the light. Without a shader, a 3D object would be invisible, existing only as a set of data points. Just like texture maps, there are numerous shader types to enable various surface types to appear realistic, like wood, metal, glass, ceramics etc. Some of the base shader types include Lambert, Blinn/Phong, Anisotropic and are generally included as standard in most 3D programs. Lambert is the most basic type which scatters light evenly around all of the object it is applied to. Blinn/Phong are used for reflective surfaces that require a strongly defined specular highlight. Anisotropic also shows highlights similar to the Blinn/Phong type, except it in this case the reflection appears as an elongated ellipse which is generally used for hair, brushed metal, and glass to name a few.
Rigging is the process of creating a skeleton for a 3D model in order for it to be moved. Without a rig, a 3D model is nothing more than a statue locked in its pose indefinitely. There are many processes and ways to rig an object to suit specific needs such as joint rigging, facial rigging, forward and inverse kinematics, blend shapes, deformers, control curves, skinning, and weight painting. The most common of these methods is joint rigging, where the model is essentially given a skeleton which has numerous joints that allow the bones to be animated. But thanks to joints, riggers can set constraints that determines how the skeleton can and can’t move. This level of control enables animators to bring the objects to life realistically or to suit the desired goal of the project brief.
The animation process is where the 3D object finally comes to life. An animator uses the rig setup in the previous step to manipulate the model through numerous key frames which is then compiled together at the end to create a (hopefully) smooth running scene or sequence of actions. This process is very similar to the way 2D flickbook works to bring a series or chain of still images to life. In 3D however, the process isn’t as tedious with the animator setting the 3D object in a certain pose for each key frame. The software package will then automatically move the model within the constraints set by the animator with the key frames.
Mike Wazowski and Boo from Monsters Inc image sourced from: http://giphy.com/gifs/disneypixar-disney-pixar-Hp4lpOT1Ns60o
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