How To : Rig a Universal Joint in Maya

Universal Joints, often called cardan joints, are a means of transferring rotational energy from one variable axis to another and are used all over the place. They're basically a pair of hinges and you'll these on drive shafts everywhere where you'll need to compensate for movement. 

How To : Create A Realistic Car Steering Rig in Maya

Turning a car is not as simple as you think. There's some quite advanced geometry at work to order to maintain the correct rotations for each front wheel in order to keep the turn 'on track'. The radii for each wheel change at a non-linear rate as the turn gets sharper.

A best practical solution is the Ackerman Steering Principle, a well documented system. Whilst not 100% perfect, it's pretty much near to and as it's used on most vehicles today, this is what we'll use as our template. No bodging here I'm afraid. For more reading and theory that I will explain here, there's an excellent Wiki page on this Ackerman Steering Geometry.

How To : Rig Accurate Working Springs in Maya

I've seen a few piston or damper rigs, and each one works well until a spring is added. All too often they use a scale system that kind of works ok for a casual inspection, but under close scrutiny falls apart because the scaling produces a noticeable flattening of the spring's cross section under extreme compression.

Here I'll discuss two other ways of achieving this effect with near complete accuracy, and along the way we'll create a couple of rigs in order to demonstrate these techniques.

This gif on the right  is what we're aiming for, a self contained rig that can be used almost anywhere, and will not exceed it's limits. The first method I'll discuss involves Maya's blendshapes.

How To : Create Hoeken's Linkages in Maya

Hoeken's Linkage is quite a special thing, really, it is. It sounds stuffy and technical and yes it is, but trust me it's also quite amusing. No doubt you've seen it before and is remarkably simple.

This linkage is a special case of a four bar linkage system where it converts rotational motion into constant linear motion in such a way as to produce an approximate stepping motion. This motion could be used to provide the mechanism for a walk, a conveyor belt, or other types of modified stepped motion.

How To : Animate Cranks and Pistons in Maya

figure 1

A recent project I worked on required the modelling of an animating crank and a piston similar to those used by steam locomotives. Engines that use pistons as a power source need a way of converting the back and forth (reciprocating) linear piston motion into rotational motion. Cranks are used to do this and these are connected to points that are offset from the main rotational axis on what is called the crankshaft, and these in turn are connected to the pistons. The crankshaft is the part that receives the rotational energy. The system will also work in reverse, turning the rotational movement into linear.

So that's how it works in the real world, so how do we translate this into Maya?