Author Archives: Dalton Witham

Maya Bone Skeleton System: Individual Research Dalton Witham

The bone skeleton system in Autodesk Maya is used for animating geometries. This is done through the use of the skeleton and the joints the associated with each part of the skeleton. There are child joints, the secondary joints, and parent joints, or the main joints. When animating the actual skeleton you use kinematics. Kinematics is a branch of classical mechanics that describes the motion of points, objects, or a system of objects without considering the causes of motion. So basically it is only moving the joint without thought of how the joints should logically be moving in connection to one another.

In order to solve that problem, Forward Kinematics is used to create a joint hierarchy among all of the joints within the skeletal system of the object. This means that the parent joints in the object will control all of the child joints connected to it, and those child joints will move with the related parent joints. But this causes another problem within itself. When animating a bipedal character to walk. The bipedal character will place its foot on the ground, and logically that foot should remain on the ground until it is lifted off of the ground again. But while using only Forward Kinematics, when there is any movement in the hips or legs that takes place, the foot will also move and not remain planted on the ground, as it should. So in order to solve this problem we turn to Inverse Kinematics.

Inverse Kinematics consists of a more complex system that allows you to calculate the movement of the parent joints and move the related child joints according to where you allow them to move. There are several different types of solutions that you can find when using Inverse Kinematics. The first being, Single Chain Inverse Kinematics Solver, which works best while animating an object in Two Dimensions. It allows you to control the movement of joints compared to their related parent joints. Next there is the Rotate Plane Inverse Kinematics Solver is another type of solution that is similar to the Single Chain Inverse Kinematics Solver but also allows you to rotate the orientation as well. This solution works extremely well while animating in Three Dimensions. The third type of solution found in Inverse Kinematics is called Inverse Kinematics Spline Solver. This is based off of the use of a NURB curve and a Spline curve. What it does is help with the issue of forward kinematics in curved elements within an object through the use of a spline. For example when animating a human skeletal system, the spine or neck of the system will have to be animated with Inverse Kinematics Spline Solution due to the natural curvature of those elements.

The simple operations of Forward Kinematics and more complex operations of Inverse Kinematics will ultimately be blended together using a technique call FK/IK blending. This is done to give the animator a more logical control of the object or objects that he is animating.

004 Dalton Witham

Ball State University gave a small group of recent graduates, also known as PROJECTiONE, one week to create this site-specific instillation. EXOtique was the result. It is a dropped ceiling located in the west entrance of the campuses architecture building. The idea behind EXOtique was to create a simple piece, constructed using a hexagonal system to act as the suspended ceiling for that space that would also light up. EXOtique is suspended only using the hangers required for the lamps used.

I think this project is particularly interesting due to its simplicity and also its dynamicity. Its form creates a smaller space for the room that it is in due to its changing ceiling height. EXOtique is also a lit installation, which adds an interesting lighting quality to the room. All of the light from the installation is diffused through the piece itself.

What I find most interesting about this project is the amount of time it took to produce it. One day dedicated to design, one day to model, and the rest were assembly and installation. For such an elegant piece to be constructed in such a short amount a time is an achievement in itself.

source: http://www.core77.com/blog/architecture/exotique_digital_fabrication_in_a_week_18871.asp