Getting a grasp on Pixels' IK tools can be disconcerting to new users. The purpose of this tutorial is to clear up some common misconceptions, and to give you a better understanding of the IK.

This tutorial requires:

Pixels3D | studio | v3.x
Understanding of Pixels3D | studio Basics

Create a Default Cylinder.

Rotate it 90 Degrees on the x-axis, and park it.

Choose Shape>IK Chain.

Click just Above the Cylinder, then in the center of it, then just below it. Press the ESC Key to complete the chain.

When prompted, give it a name, or accept the default.

Change the Right View to Schematic View.

In the Schematic view, select the Cylinder, then Shift-Select the root of the IK Chain (IKChain_root).

Choose Control>Link and accept the default link options.

The IKChain is now the parent of the cylinder.

Select IKChain_jnt2, and move it around. Notice the Cylinder is only conforming to the angle set by the first segment of the chain. Why? By linking the cylinder to the root of the chain, we are telling Pixels to link every CV of the Cylinder to the first segment.

Undo any movement so that the cylinder is vertical once again.

Select only the Cylinder.

Enable Tag mode, and tag the lower portion of the Cylinder.

The lower CVs are now linked to the 2nd Segment of the IK Chain.

Note: You can link any CV of any object to any IK Segment in the scene. Simply use the above step. This is where the real power of the application becomes apparent. Multiple IK Chains can be used for a single object, or Multiple Objects can be linked to a single IK Chain; It's all up to you.

Move the last IK Constraint once again, and notice the cylinder bends, but is very rigid..

In the Point Info window, there is a slider to control the weight ( influence ) the IK chain has on every individual CV. IK Weights are used to achieve more organic flexing of objects. Think of the weight value as a rigidity setting, whereas 0.0 is completely unaffected by the IK chain, and 1.0 completely enslaves the CV.

We can set the weight for every single CV individually, by selecting the CV, and dragging the IK Weight Slider; however this is very time-consuming.

Tag mode can be used to set the weights for several points at once. Simply tag the points, and drag the slider in Point Info.

The image on the right shows a very basic weight layout. The object should soften & 'give' a little at the joints, and gradually taper to rigidity in the middle of the IK segments.

When a patch is child to an IK Chain, the segment of the chain essentially becomes a rotation axis for the patch.

As an example, by selecting IK_Chain_jnt1, and rotating it on the Y-Axis, the portion of the cylinder linked to this segment will rotate on the Y-Axis, even though the segment is arbitrary to the main axes.

If the cylinder was an arm, the rotation of the IK constraint would create wrist-twist.

Now, the important part -

Let's say this cylinder is a character we're going to animate. In its current state, we would run into problems trying to move or rotate the entire character ( flips, spins, complex motion, etc...).

To avoid these complications, we will create a new coordinate system strictly for the character.

How do we do this? Simple, use a Null.

Choose Shape>Null.

Scale is up until it is larger than the character, then Park it. This makes it easier to select in the views.

In the Schematic View, Select the IKChain, then Shift-Select the Null.

Choose Control>Link, and accept the default.

The IK_Chain's Coordinate System is now derived from the Null, not the scene. Therefore, we can do any arbitrary rotations of the entire character without the scene's up-vector mangling the IK Math and playing twister with the character.

Remember, to move the Entire Character, move only the Null. To move or rotate any part of an object linked to an IK Chain, only move or rotate the IK_Constraint.