Animation
skeletal
is a computer animation technique, this is particularly used in the animation of vertebrates, where a character is represented into two parts, a surface representation used to draw the character, called the skin, and a hierarchical construction of bones used only for animation, this is called the skeleton.
This technique is used to build a series of "bones", each bone has a transformation three dimensions, which includes position, scale and orientation, and an optional parent bone. In this way the bones are a hierarchy. The complete transformed a child node is the product of his father and transformed itself transformed. So move the thigh bone will also move the shinbone. As the character is animated, the bones change their transformation over time while under the influence of some animation controls.
Each bone skeleton is associated with any portion of the visual representation of the character. In the most common case of a character polygonal mesh, the mesh is associated with a group of vertices, for example, in a model of a human thigh bone will be associated with the vertices are the polygon model of the thigh . Portions of the character's skin can be associated with multiple bones, each having a scale factor called the vertex weight, or weight of the mixture. The movement of the skin near the joints, can therefore be influenced by the two bones.
For a polygonal mesh, each vertex can have a mixing weight for each bone. To calculate the final position of the vertex, each bone transform is applied to the position of the vertex. Scaled by its corresponding weight. This algorithm is called matrix palette of skin, because the whole blood processed, stored and transformed matrices, form a palette for each vertex of the skin to get elected.
skeletal animation is useful because it enables animators to control only those features of the model that move independently. A character can not move your lower shin at the top regardless. Instead of making a vertex by vertex animation just move the bone and it s related vertices. The disadvantage of this type of animation is that it provides a realistic animation of the muscles, to solve this special controls are added muscle which are attached to bones, all to represent the full movement of the muscle.
skeletal animation is a standard way to animate characters or mechanical objects for a long time, usually more than 100 pictures, is generally used in video games and film industry can also be applied to mechanical objects and any other object with rigid elements joints.
FBX
FBX provides a universal 3D asset exchange, this is an exchange format and 3D CREATION, platform independent and completely free (but not free), the FBX file format supports all major 3D data elements and 2D elements, audio and video media.
in if FBX format is a mix between binary and ASCII code, because it can handle, store, convert and convey complex 3D scenes with 2D agreed, as an example of this is:
· polygonal meshes and NURBS
· mapping of textures and materials
· normal vertices per vertex color mapping
· Links checkpoints
· Multiple cameras and camera exchange
· Multiple types of lights
· Bookmarks
· skeleton segments (root, limbs and extremities nodes)
· Several shots mocap animations
· positions in a linked list of nodes
· video clips (embedded or referenced)
· audio clips (embedded or referenced)
· Shaders
Format X
X format The DirectX file format, this format is an architecture and file format free of context. It is driven by templates and is free for any use. The file format may be used by any client application and is currently being used in Direct3D Retained Mode to describe the geometry data, pictures and animation hierarchy
format. X stores everything in a hierarchical approach. Each level of the hierarchy can have any number of "objects" to keep data, but you should only have a small number of "objects" for each level. The "object" principal geometric hierarchy model is a picture. For animations, the "object" in the hierarchy is a set of animation.
0 comments:
Post a Comment