Jack is a human modeling and simulation software solution that helps organizations in various industries improve the ergonomics of product designs and refine workplace tasks. Jack enables you to:

• Build a virtual environment
• Create a virtual human
• Define your human's size and shape
• Position the human in your environment
• Assign your human tasks
• Analyze how your human performs

The information you obtain from Jack can help you design safer, more ergonomically sound products, workplaces and processes faster and for less cost.

STEP 1: Build a virtual environment

In addition to its strength as a human modeler, Jack is a powerful interactive, real-time visual simulation solution. You can import CAD data or build models from scratch with the software, move objects around in the environment, interactively change camera views and create special effects to enhance the realism of your "scene."

Import CAD models -- Jack can import 3D graphics data based on vrml, iges, stereolithography (stl), and inventor (iv) file formats. In addition, the software provides options for reducing CAD data to optimize models for use in real-time simulations. Utilities from OpenGL Optimizer and Decimate dramatically reduce the number polygons in a model without compromising the visual fidelity required for realistic simulations.

Create geometry in Jack -- Jack allows you to build models from scratch for use in evaluating conceptual designs. You can create such geometric primitives as cubes, spheres, cylinders, cones and toroids. By manipulating segments, you can merge primitives to build representations of more complex parts such as machine tools and vehicles. Jack also provides a set of basic tools (hammer, pliers, ladder, ratchet, saw, screwdriver and wrench)

Give your environment a realistic appearance -- Jack's viewing, texture mapping and lighting capabilities help you give your virtual environment a more convincing appearance.

Changing the view in Jack is easy; the mouse buttons enable you to swing the "camera" horizontally or vertically and to zoom in on a reference point. Additionally, you can snap the view reference point to a specified object, attach the view camera to an object such as a human figure's eyes, and create "cutaway" views of a scene. With texture mapping, image files of elements such as clouds, roads, factory interiors or machine control panels can be used to add visual detail to scenes without adding extra geometry. Classic Jack's lighting capability helps you highlight areas of your environment and enhance the realism of a scene.

STEP 2: Create a virtual human

Jack provides the industry's most biomechanically accurate human models. Based on body dimension measurements taken from the 1988 Anthropometric Survey of U.S. Army Personnel (ANSUR 88), Jack human figures:

• have 69 segments, 68 joints, a 17-segment spine, 16-segment hands, coupled shoulder/clavicle joints and 135 degrees of freedom
• obey joint limits derived from NASA studies (Anthropometric Source Book, Vol. 2: A Handbook of Anthropometric Data, Technical Report NASA RP-1024)
• can be represented as stick figures, wireframe, shaded, high-resolution or transparent model

Choose from various types of humans -- Jack enables you to create various types of humans. You can choose from a menu of the following predefined human figures:

• Large, medium and small humans, as defined by SAE measurements -- based on SAE recommended human physical dimensions (SAE J833)
• Short and tall man and woman - human figure extremes based on ANSUR 88 data
• Large, medium and small Japanese humans - based on recognized Japanese body size data
• High resolution man and woman - detailed representations of 50th percentile males and females, as defined by ANSUR 88

STEP 3: Define your human's size and shape

For human simulation software to reliably determine whether a design accommodates the variability among human body dimensions, it must employ a correct approach to human figure scaling. Jack uses three approaches to anthropometric scaling. You can:

• Choose body types from a boundary manikin set of 77 figures that represent a range of sizes for 11 body dimensions taken from the ANSUR 88 database
• Construct figures by specifying the extreme dimensions for a segment of interest, such as shoulder breadth, sitting height, etc; an algorithm then proportions the remaining figure dimensions automatically
• Scale figures by specifying stature and weight; remaining dimensions are automatically generated using statistical models based on the ANSUR 88 database.

STEP 4: Position the human in your environment

Jack allows you to manipulate individual body segments connected by joints that obey angle limits derived from NASA studies. As you move a body segment on a Jack virtual human, the software uses real-time inverse kinematics to determine the position of linked segments and joints. For instance, when you move a figure's hand, the upper and lower arm segments and related joints move like you would expect a human body to move.

Set your virtual human's posture -- Jack allows you to describe the posture of your virtual human by directly manipulating body joints or by choosing from a library of 30 predefined postures. You can manipulate a Jack virtual human by moving its head, eyes, shoulders, torso, center of mass, pelvis, arms, feet or its entire body.

Specify Jack's behavior parameters -- Jack allows you to specify how a virtual human "behaves" when its movement is controlled, not by dire-ct manipulation, but by external forces. The Jack figure then automatically moves according to the parameters you define. For instance, if Jack is holding an object over his head and you put the object on the ground, "behavior controls" determine whether Jack will bend at the waist, take a step to maintain his balance, keep his eyes fixated on the object, etc. Jack allows you to define:

• Bring factories on-line faster
• Optimize manual workflow
• Improve worker safety
• Lower workers' compensation costs
• Reduce downtime and retraining costs

In the manufacturing phase of the product lifecycle, human simulation allows you to answer these questions:

• Whether the head and eyes track an object
• Whether or not the head and eyes hold their position
• How the torso is positioned and how it bends (from the waist, curling from the neck, or using specific vertebrae)
• How the figure maintains its balance and whether it takes a step to regain balance
• How the pelvis is oriented
• How the arms are positioned
• How the knees are positioned
• How the feet are positioned

Define Jack's relationship to the environment -- Jack's constraint system enables you to specify how your virtual human interacts with its virtual environment. Jack allows you to define constraints between human figures and objects in a variety of ways. For instance, you can create constraints that keep Jack's lower back attached to a car seat, and his right foot attached to the accelerator. When the seat is moved, Jack will obey these constraints, and the rest of his joints will move accordingly.

To define how human figures grasp objects, Jack provides five predefined grasp types. You specify the grasp type and the software calculates how to close the hand realistically around a given object.

STEP 5: Assign your human tasks

For some types of human factors or ergonomics studies, users simply need to evaluate Jack in a static position. (What can he see while reaching for a given control? Do different-sized figures have the same field of view?) Other studies require Jack to move. (Can Jack reach around an obstacle to remove or replace a part?) Jack enables you to define the movements of human figures with its built-in motion system and its interface to VR tools.

Direct the movement of your human figures -- Jack provides a built-in motion system for defining tasks that must be performed under time constraints. Jack simulations consist of several distinct motions, many occurring simultaneously, defined over a specified interval of time. You can create motions interactively in Jack to control the movement of the head, eyes, torso, pelvis, center of mass, arms, hands, feet, and more. In addition, you can make objects and the camera perspective move.

After you create a simulation, you can save it and replay it, swapping in different-sized virtual humans to perform the same tasks. Alternatively, you can adjust the size or position of various objects in the environment and re-run the simulation to study changed spatial relationships, timing and clearances.

Use Virtual Reality tools to define human motion -- Jack enables you to work with a variety of VR tools to create realistic motions or to experience a simulation. The software supports:

• Ascension Technology's Flock of Birds
• Virtual Technology's Cyberglove and Cybergrasp
• Virtual Research Systems' Head Mounted Display
• Stereographic's Crystaleyes
• NuVision Shutter Panels

STEP 6: Analyze how your human performs

Jack provides a number of basic tools to help you evaluate the performance of your virtual humans. More advanced ergonomic analysis tools are available with the optional Task Analysis and Occupant Packaging Toolkits.

See what Jack can see -- Jack offers several features for evaluating visibility. You can:

• Create Eye Windows to see from Jack's point of view
• Create View Cones to illustrate a 'third-person" perspective of what Jack sees
• Measure distances between Jack's eyes and any object
• Set Jack's head/eye control to track an object's movement

Evaluate what Jack can reach -- Jack's reach analysis capabilities enable you to:

• Determine whether a human figure can reach a target object
• Measure the distance between Jack's hand and any object
• Create and position reach envelopes to graphically display what large, medium and small SAE-defined humans can reach
• Export reach envelopes to your CAD system to serve as design boundaries

Test fit and accommodation -- Jack helps you to determine whether your design accommodates various-sized humans. You can:

• Position one virtual human, then use that posture to test a range of different-sized humans
• Interactively measure distances between any two points in the environment as their relative positions change; this helps quantify the extent to which a design accommodates your target population
• Highlight collisions in real-time between human figures and objects as objects move

Calculate human force and torque -- Jack enables you to compute the forces on a human figure's joints and segments in a given posture. With the results, you can compare the forces that must be exerted to accomplish various tasks. The software also allows you to factor in the weight of objects that your virtual human is holding and to represent additional external forces, such as a g-force.

Use animations and images to communicate your findings -- Jack's ability to generate compelling animations and still-frame images helps communicate your findings in a way that statistical reports can't. You can create anti-aliased .rgb images of any scene in Jack. And you can easily turn your simulations into .avi or Quicktime movies.