How to build your skeleton in your favourite 3D package referring to the outlined specifications?

How to export your scene to an FBX (Filmbox) file using the free plugins from the Kaydara web site
(note, we're using Filmbox 3.5)

http://www.kaydara.com/customer_services/download/index.php?filename=plugins
- Save this template scene in your package's native format -

Required Elements (red):

• a reference null object, placed between the 2 feet
• 1 hips joint, child of the reference
• use a minimum of 1 spine joint, and a maximum of 10 spine joints, first joint is a child of the hips, 2nd joint is a child of the 1st joint etc...
• 1 head joint, which is a child of the last spine joint (or a child of the auxiliary neck joint when used)
• 1 joint for each upper arm, which are children of the last spine joint (or children of the auxiliary shoulder joints when used)
• 1 joint for each forearm, which are children of the upper arms
• 1 joint for each hand, which are children of the forearms
• 1 joint for each upper leg, which are children of the hip joint
• 1 joint for each lower leg, which are children of the upper legs
• 1 joint for each foot, which are children of the lower legs

Auxiliary Elements (blue): (not required, but usually of great help for proper deformations):

• 1 joint for the left toes, child of the left foot joint
• 1 joint for the right toes, child of the right foot joint
• 1 joint for each shoulder, which are children of the last spine joint and are a parent of the upper arm joints
• 1 joint for the neck, which is a child of the last spine joint and a parent of the head joint

• Each finger must have 3 joints(including the thumb)

Roll Elements*(yellow)(not required but see below for an explanation):

• 1 joint for each upper arm roll, children of the upper arm joints, parents of the forearm joints
• 1 joint for each forearm roll, children of the forearm joints, parents of the hand joints
• 1 joint for each upper leg roll, children of the upper leg joints, parents of the lower leg joints
• 1 joint for each lower leg roll, children of the lower leg joints, parents of the feet joints

The naming of the joints can be anything you like as long as it's clear.

Creating a deformation setup which works in ANY pose usually is a task that's nearly impossible. Generic poses might look good but for some very extreme poses with high amounts of rotations deformations might start to look unnatural. When animating a character using keyframe animation the animator can see when a joint is rotated to much and keep the pose within that restriction.

Since motion capture can put pretty extreme motions through a skeleton you will need to make sure your deformation setup can handle it. What can drastically help improve your deformations is using the concept of Roll joints to help in deforming your characters limbs correctly.

The idea is to introduce extra joints halfway up the upper arm, forearm, upper leg and lower leg that only receive the roll-motion. (motion along the bone itself) That way the deformation of that roll motion will not fully occur at the joint (the shoulder for example) but will be more gradually distributed along the limb resulting in more natural deformation.

The character must be delivered in the so called "Da Vinci" or "T-pose". With the legs straight down, the feet pointing straight forward, the arms horizontally with the hand palms facing down to the floor. The fingers should be straight, the thumb should be straight but pointing in the same direction as the fingers do.

Maya specific notes:

• Use polygons or nurbs surfaces
• When you need to use Subdivision surfaces convert them to polygons for the scene that will be exported to Filmbox
• Make sure that all scaling and rotations have been properly frozen
• Negative and/or non-uniform scaling is not supported
• Use "smooth bind" or use "rigid bind" but don't use lattices or other deformers for the scene that will be exported to Filmbox.

Softimage specific notes:

• Use polygons, patches or nurbs surfaces
• Make sure you "freeze scaling" on all the bones.

3DMAX specific notes:

• Make sure that you reset all transformations, the pivot and scale of your models.