Truck (rigging)

A truck is a nautical term for a wooden ball, disk, or bun-shaped cap at the top of a mast, with holes in it through which flag halyards are passed. Trucks are also used on wooden flagpoles, to prevent them from splitting.

Without a masthead truck, water could easily seep into the circular growth rings of a wooden mast. However, the grain in the truck is perpendicular to that of the mast, allowing the water to run off it.

References

Rigging

Rigging (from Anglo-Saxon wrigan or wringing, "to clothe") is the apparatus through which the force of the wind is used to propel sailboats and sailing ships forward. This includes masts, yards, sails, and cordage.

Terms and classifications

Rigging is the mechanical sailing apparatus attached to the hull in order to move the boat as a whole. This includes cordage (ropes attached to the spars and sails in order to manipulate their position and shape), sails (aerofoils, usually made of fabric, used to catch the wind), and spars (masts and other solid objects sails are attached to). Cordage is more usually the term for stocks of rope, yarn, or other types of line in storage, before it has been put to some use in a vessel, whereafter is commonly referred to as part of the rigging.

Certain sail-plans are used for certain purposes according to their aerodynamic properties. All sailing vessels are classified according to their hull design and rigging.

In Antiquity, ships used only oars during battle. The sails could hinder the quick maneuvers needed in advancing the warship. Since the main rig took time to put up and take down, they implemented another rig, which was capable of being erected faster than the main rig. It was called the emergency rig, and was named as such because its main use was to get the ship to sail (away) faster if it got into trouble and the crew was not able to get the main rig up quickly enough. There is question on what equipment was in the emergency rig. Since there are no pictures/drawings of the emergency rig in use there are questions as to what exact material it consisted of. There is a comparison of the rig to a bow-sail, because it could be carried at all times. After the 4th century BC the existence of the emergency rig is questionable in the Athenian Navy, because there is evidence that the entire emergency rig was substituted for a lighter sail.

Fly system

A fly system, flying system or theatrical rigging system, is a system of lines (e.g., ropes), blocks (pulleys), counterweights and related devices within a theater that enables a stage crew to quickly, quietly and safely fly (hoist) components such as curtains, lights, scenery, stage effects and, sometimes, people (e.g., in Peter Pan). Systems are typically designed to fly components between clear view of the audience and out of view, into the large opening, fly loft, above the stage.

Fly systems are often used in conjunction with other theatre systems, such as scenery wagons, stage lifts and stage turntables, to physically manipulate the mise en scène.

Theatrical rigging is most prevalent in proscenium theatres with stage houses designed specifically to handle the significant dead and live loads associated with fly systems. Building, occupational safety, and fire codes limit the types and quantity of rigging permitted in a theatre based on stage configuration. Theatrical rigging standards are developed and maintained by organizations such as USITT and ESTA (now PLASA).

Skeletal animation

Skeletal animation is a technique in computer animation in which a character is represented in two parts: a surface representation used to draw the character (called skin or mesh) and a hierarchical set of interconnected bones (called the skeleton or rig) used to animate (pose and keyframe) the mesh. While this technique is often used to animate humans or more generally for organic modeling, it only serves to make the animation process more intuitive and the same technique can be used to control the deformation of any object — a door, a spoon, a building, or a galaxy. When the animated object is more general than for example a humanoid character the set of bones may not be hierarchical or interconnected, but it just represents a higher level description of the motion of the part of mesh or skin it is influencing.

This technique is used in virtually all animation systems where simplified user interfaces allows animators to control often complex algorithms and a huge amount of geometry; most notably through inverse kinematics and other "goal-oriented" techniques. In principle, however, the intention of the technique is never to imitate real anatomy or physical processes, but only to control the deformation of the mesh data.