Animation Terms – 3D/Maya
This is the third post in a five part series. The following is a list of terms associated with 3D Animation and the software most commonly used for 3D Animation – Autodesk Maya. Most of these terms are commonly used in a 3D Animation environmentâ€¦
Axis – In 3D software we work in virtual three dimensional space. To keep track of where we are in this space we use three dimensions (thus 3D). The three dimensions are X, Y and Z. It can be explained this way – X axis being east/west, Y axis being up/down, and Z axis being north/south. Every object created in 3D software has xyz translations(to move any way), xyz rotations(to rotate any way), and xyz scale values(to scale to any size). We refer to a dimension as an “axis”. e.g. – “I rotated the cube on the X axis”.
Bump Map – An image file whose Black and White values are used for the shadow information in rendering the surface of a Computer Generated object, making the object look bumpy.
Channel Box – Part of Maya’s interface (usually in the right sidebar). This section of the interface shows you which object is currently selected and all of that objects channels. e.g. translate x,y,z/rotate x,y,z/scale x,y,z and a visibility channel. Other attributes are also displayed.
Channels – Every 3D object has Translate, Rotate and Scale channels which are keyable attributes. This is how 3D objects are animated – by keying the objects channels.
Clipping Plane – In 3D software, Near and Far Clipping Planes are user defined distances (orthographic planes) from the camera between which all geometry is displayed, beyond which no geometry is displayed.
Constraints – A function in most 3D software packages that limits an objects movement or behavior in some way. There are several types of constraints – Maya’s constraints are Point, Aim, Orient, Scale, and Parent constraints. Often used in rigging characters. Also can be used to get objects to “stick” to a character. e.g. – May be used to have an object stick to a character’s hand after picking up an object.
Displacement Map – An image file in which Black and White values are used to affect the actual geometry of a Computer Generated object before rendering its surface.
Forward Kinematics – Usually referred to as FK. A method of animating a hierarchy or chain of bones by rotating each joint separately to achieve the desired position in 3D space. FK is often used for characters arms, although some animators prefer IK arms (see also Inverse Kinematics).
Frame Buffer – A portion of a computers memory dedicated to the storage of an image so it can be recalled, manipulated or pasted into anther file.
3D Geometry – The surfacing or skinning used in 3D software from which all objects are created. Can come in the form of nurbs surfaces (Nurbs), polygonal surfaces (Polygons), or subdivision surfaces (Sub-D’s). Which surfacing method to use (when modeling objects) is usually a preference of the user – the different surfaces have their own properties and capabilities.
Gimbal Lock – Occurs when X, Y, and Z axis of rotation is lost to the user. It manifests itself in two of the rotational axies appearing to have the same effect on a CG models rotation.
Graph Editor – A tool in Maya that is most commonly used by animators to refine animation using spline curves, most commonly referred to as “animation curves”. All key-frames, and the space between the key-frames can be edited in the Graph Editor.
Hierarchy – A Hierarchy is composed of a series of nodes that are combined for some purposeful relationship. Hierarchies are structured in a top-down manner, with one node at the top (the parent node or root node) and other nodes (child nodes or leaf nodes) attached and interconnected beneath the top node.
The Hypergraph – A window in Maya that shows how the nodes and their connections are organized in your scene. You view object hierarchies and dependencies in the Hypergraph.
The Hypershade – A window within Maya that serves as a central working area for Maya rendering. This is where you put color and textures to objects. More advances functions include building shading networks by creating, editing, and connecting rendering nodes, such as textures, materials, lights, rendering utilities, and special effects.
Inverse Kinematics – Usually referred to as IK. A method of animating a hierarchy, or chain of bones with an IK handle by simply translating the last bone at the end of the chain; each joint in the chain is automatically rotated by an IK Solver. Usually used for characters legs.(see also Forward Kinematics).
Lens – The optics of a camera. In 3D software a virtual camera is created and used to shoot animation. This virtual camera duplicates the properties of a real world camera – properties such as f-stop, focal length, film gate, aperture, etc.
Matte – A separate black and white image that controls the transparency values of every part of the frame of a composited or rendered image. Mattes are used for leveling objects from BG to FG and for creating the illusion of transparency of an object. (see Alpha Channel).
3D Modeling – The process of molding 3D geometry into the desired object or character.
Node – A sort of placeholder in 3D software that represents the attributes of a CG object and into which numerical data may be stored, processed then piped into another node. For example, on a 3D character, the control for each body part has it’s own node.
NURBs Curve – Non-Uniform Rational B-Splines are spline curves used in modeling. The curve’s shape is defined by CV’s (Control Vertices) that lie off the path of the curve. CV’s are joined by Hulls. The curve passes through Edit Points. (see also Spline Curves).
Orthographic View – A camera view in which parallel lines do not appear to converge. Objects appear perfectly flat. This refers to the side, front, and top view panels in 3D software.
Outliner – A window within Maya that allows you to view hierarchies and make selections.
Panels – The viewing areas in which you work. Orthographic views and a perspective view panel.
Playblast – A function within Maya that lets you preview animation quickly by performing a screen grab of the view at each frame then blasting the resulting images to a movie player for viewing. Animators use this constantly to check the progress of their animation.
Polygon – A type of surfacing used in 3D software. An individual polygon can take the shape of a triangle or quadrangle. In polygonal modeling one can edit the faces of the Polygon, the edges between the polygons and the vertices (the points where the edges converge).
Primitives – The basic geometrical shapes from which objects and characters are built. For example, in Maya the Polygon Primitives are Sphere, Cube, Cylinder, Cone, Plane, and Torus.
Rendering – Computer Generated images made from calculating all of the models lights, texture, and animation information.
Texture Map – An image file that is used for the color information in rendering the surface of a CG object.
Time Slider – At the bottom of the Maya interface is a time slider. This is where most animators set key poses and adjust the timing of their animation. On the time slider there are numbers which represent frames (like frames of a film).
Toolbox – Mayas’ tool box is usually located on the left side of the interface and contains tools to Move, Rotate and Scale 3D objects once they have been created.
Spline Curves – Commonly referred to as Animation Curves. In Mayas Graph Editor, these curves are a graphic representation of an objects motion. These curves have control points that can be controlled by handles. Mays Graph Editor is normally used to refine animation.