Perform a good Range of Motion (ROM)

The following information covers a range of motion (ROM) that helps you achieve good calibration for your subject. The range of motion is a series of movements performed by an actor that Shogun uses to generate a skeleton based on the subject's size, proportions, and the extent of their movement. The ROM is made up of individual motions such as the Raised leg kick and Elbow roll.

A good calibration results in the highest possible accuracy in capturing the performance and reduces the cleanup effort during post-production. Range of motion refers to a series of movements performed by an actor that the software uses to generate a skeleton based on the subject's size, proportions and the extent of their movement. Some studios refer to this as “the Dance” and range of motion is often shortened to ROM.

All of the motions on this page come with a set of directions that you can give to the actors who are performing the ROM.

In Shogun Live, use the Subject Calibration Feedback panel to see your subject's calibration progress. For a good calibration, aim to have a coverage of at least 30% for each joint. If a joint has at least 30% coverage, its corresponding progress bar turns green. Joints that have at least 30% coverage are better calibrated and we recommend you aim for at least 30% coverage on as many joints as possible. For more information on the definition of coverage and the subject calibration feedback, see Calibrate a subject.

We recommend working through each motion outlined in this page, and then returning to any joints that need additional coverage after each motion has been completed.

The range of motion covered in this guide are:

A-pose

An A-pose is the first motion of any ROM and any selected template. An A-pose is required because it is a pose that Shogun can recognize in the absence of calibration data. Shogun can recognize many poses, but an A-pose enables the software to boot the marker labels onto the subject.

For an A-pose, ask the actor to stand with their feet hip-width apart and to straighten their arms with their hands pointed at the floor. This pose looks like an arrow or the capital letter “A”. If Shogun can't find the subject’s A-pose, see Troubleshoot subject calibration.

Open

When the actor stands in an A-pose, check the Tracking panel and look for the Accept A-pose button. If Shogun has recognized your actor’s A-pose, the button becomes active, and you can see the subject’s skeleton tracked in the 3D View.

To begin your calibration, click Accept A-pose.

Open

Hip rotation

Ask the actor to keep their feet hip-width apart and bow forward. As they bow, have the actor lean their upper body to one side and make a circular motion with their torso. Ensure the actor leans backward as they return to the upright position. Tell the actor to imagine they are trying to draw a giant circle at a 45-degree angle with the volume floor, using only their head.

Joints covered :

• Hips, which include:

  • Spine

  • LeftUpLeg

  • RightUpLeg

Twist waist

Ask the actor to keep their feet hip-width apart and to bring their arms up to their chest, with the palms of their hands facing the floor (you can tell the actor to imagine they are hugging a big friendly bear). Ensure the actor keeps their feet planted on the floor and their arms lifted, and then ask them to twist around so they can see behind them. Repeat this motion in the opposite direction.

Joints covered:

• Spine

• LeftShoulder

• RightShoulder

• Hips, which include:

  • LeftUpLeg

  • RightUpLeg

Roll thighs

The roll thighs motion focuses on the leg joints. While standing in the same position, ask the actor to lift one of their legs and bend their knee so it makes a 90-degree angle. Then have them rotate their leg outwards to one side. Repeat this motion with the other leg. Tell the actor to imagine they are stepping over a knee-high fence.

Joints covered:

• LeftUpLeg

• RightUpLeg

• LeftLeg

• RightLeg

• Spine

Roll arms

Ensure the actor keeps both feet still and ask them to stretch both their arms above their head. Then have them rotate their fully stretched arms forwards for one full circle and then in a backward direction. Tell them to draw large circles with both arms, at the same time and in the same direction.

The coverage of this motion focuses on the arm joints, but also covers the shoulder joints.

Joints covered:

• LeftArm

• RightArm

• LeftShoulder

• RighShoulder

Shrug shoulders

Ask the actor to plant their feet and shrug their shoulders several times. If you are struggling to get coverage with this motion, ask the actor to roll their shoulders backward and then forward.

Joints covered:

• LeftShoulder

• RightShoulder

• Head

Raised leg kicks

Ask the actor to stand on one leg and to kick their raised leg forward, to the side, and then kick behind them. Have them repeat these kicks with the other leg.

If the actor is struggling to balance, let them know that this range of motion does not have to be done quickly. Tell them to use their arms to balance as this also increases the coverage of their arm and hand joints too.

Joints covered:

• LeftLeg

• RightLeg

• LeftUpLeg

• RightUpLeg

• Spine

• LeftFoot

• RightFoot

Knee roll

Have the actor stand on one leg and ask them to bend the knee of their raised leg into a 90-degree angle. With their raised leg, ask them to draw a circle with their whole lower leg (which rolls their knee). Tell the actor to keep the sole of their foot parallel to the floor. Ask the actor to draw the circle in a clockwise direction, and then in a counter-clockwise direction. Have the actor repeat this motion with the other leg. As with the Leg kick motion, the knee roll does not have to be done quickly. If the actor is struggling to balance, you can skip this step as other motions provide sufficient coverage for the leg joints.

This motion mainly focuses on the leg joints, but it does cover the feet and toe joints also.

Joints covered:

• LeftLeg

• RightLeg

• LeftUpLeg

• RightUpLeg

• Spine

• LeftFoot

• RightFoot

Ankle roll

In a similar way to the Knee roll, have the actor stand on one leg and ask them to bend the knee of their raised leg into a 90-degree angle. With their raised leg, ask the actor to draw a circle with their toe (which rolls their ankles). Have them repeat this motion with the other leg.

Raising the leg to perform this motion makes it easier for the cameras to see the markers and therefore the joints get better coverage.

Joints covered:

• LeftFoot

• RightFoot

• LeftToeBase

• RightToeBase

• LeftLeg

• RightLeg

• LeftUpLeg

• RightUpLeg

• Spine

Elbow roll

Ensure the actor keeps both feet still and then ask them to stretch their arms out to the side to make a T-pose. When their arms are stretched, have the actor rotate their forearms parallel to their upper arms and in a circular motion. Ask the actor to try and keep their elbows in one place. This motion is similar to the propellers on a small plane. Ask the actor to rotate their arms in one direction and then in the other.

Joints covered:

• LeftForeArm

• RightForeArm

• LeftHand

• RightHand

• LeftArm

• RightArm

Wrist roll

In a similar way to the Elbow roll, ask the actor to keep both feet flat on the floor and then have them stretch their arms out in front of them. When their arms are stretched, ask the actor to rotate their forearms in the direction they are facing. One way to achieve good coverage for this motion is to tell the actor to have the palms of both their hands facing the floor and then rotate their hands so the palms face the ceiling. When performing this motion, ask the actor to keep their arms straight and to rotate their elbows inward and then outward. While performing this motion, ask the actor to rotate their wrists in a circular motion also as this provides additional coverage of the hands.

Joints covered:

• LeftHand

• RightHand

• LeftForeArm

• RightForeArm

• LeftArm

• RightArm

Head roll

Ensure the actor keeps both their shoulders and feet in a fixed stance. Then ask them to roll their head in a clockwise direction and then counterclockwise. You can ask them to imagine they are drawing a circle with the top of their head.

Joints covered:

• Head

• Spine

• Neck (Note that the Neck joint is not shown in the Subject Calibration Feedback panel.)

Lunge

Have the actor take a long step forward with their left leg while keeping their right foot at the starting position.

During this lunge, the knee of the left leg has a roughly 90-degree bend, with the right leg extended behind the actor. This motion usually causes the actor to raise their right heel, which provides coverage to the right toe joints. To get more toe coverage during this motion, ask the actor to keep their right foot flat on the floor and then raise the heel of their left foot, bending their knee slightly.

Return to the starting position and repeat with the opposite leg.

Use this motion to get better coverage of the toe and foot joints.

Joints covered:

• LeftToeBase

• RightToeBase

• LeftFoot

• RightFoot

• LeftLeg

• RightLeg

• LeftUpLeg

• RightUpLeg

Motion for fingers

The next few finger motions ensure better coverage of finger joints. If the template you have chosen doesn’t require coverage of the finger joints, these motions are not necessary.

If your skeleton template has finger joints, you can follow the progress of coverage for these joints by looking at VRA:Lefthand and VRA:Righthand in the Subject Calibration Feedback panel.

Wiggle fingers

Ask the actor to extend their arms in front of them and wiggle their fingers. You can tell them to play an invisible piano.

Joints covered:

• VRA:LeftHand

• VRA:RightHand

VRA joints are collected into VRA groups to make the Subject Calibration Feedback panel less cluttered and easier to read.

Fingers to thumb

Have the actor extend their arms in front of them with their fingers spread on each hand. Then have the actor pinch each of their fingers on one hand towards their thumb, keeping their thumb in place. Do this for both hands.

Joints covered:

• VRA:LeftHand

• VRA:RightHand

Pinch and flex fingers

Ask the actor to extend their arms in front of them with their fingers spread on each hand. Then have the actor pinch all of their fingers against their thumb. Then have them quickly expand their fingers so they are spread out again. Repeat this pinch and flex motion several times. Tell them to imagine they are performing with an invisible sock puppet.

Joints covered:

• VRA:LeftHand

• VRA:RightHand

Crouch

Have the actor place their legs hip-width apart, extend their arms in front of them, and squat down as low as they can. This crouch motion can be done slowly if necessary.

This final motion covers all the leg joints again and helps to finalize the calibration.

Joints covered:

• LeftLeg

• RightLeg

• LeftUpLeg

• RightUpLeg

• LeftFoot

• RightFoot

• LeftToeBase

• RightToeBase

• LeftArm

• RightArm

• Spine

Additional calibration steps

In the Subject Calibration Feedback panel, check to see if any joints have less than 30% coverage.

If any joints require more coverage, repeat the corresponding motions until the progress bars turn green. If you’re still not getting enough coverage for these joints, ask the actor to face a different camera or go to a different part of the volume and repeat the motions that cover the joints that require more attention.

While 30% coverage is the goal, ultimately the best calibrations are those that adequately represent your actor's ability to move comfortably and naturally.