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Start Page » DEMoCap: Drag[en]gine Motion Capture » Motion Transfer Tracker

Motion Transfer Tracker

Most motion transfers use VR devices as input to do calculations. For every use of such VR device motion transfers have tracker parameter. This parameter is shown in the UI as a collapsible group typically with a name like “Tracker”, “Base Tracker” or similar. The information in this page applies to all such uses.

Slot

Tracker slot to use. List shows all tracker slots defined in the character configuration. If no slot is assigned the tracker is not altering the functionality of the motion transfer. See the documentation page of each motion transfer to learn which trackers are mandatory and optional.

Position

Position offset relative to tracker target coordinate system.

Click on the label or any of the text fields next to it to activate coordinate edit mode. In the preview window a coordinate gizmo is shown. You can move the coordinate system which updates the position in the text fields or you can enter values directly.

Most of the time you leave this at 0 for all components.

Rotation

Rotation offset relative to tracker target coordinate system.

Click on the label or any of the text fields next to it to activate coordinate edit mode. In the preview window a coordinate gizmo is shown. You can rotate the coordinate system which updates the rotation in the text fields or you can enter values directly.

Most of the time you leave this at 0 for all components.

Auto Transform

Sets how the transform from the reference coordinate system to the target coordinate system is calculated.

The reference position for each tracker slot type is calculated from the actor profile parameters and represents the location on the motion capture actor. This is called reference space since this provides a well defined coordinate system no matter what VR input device is used nor how it is placed and oriented.

It is recommended to use “Full” or “Orientation”.

Full

Attaches the target coordinate system to the reference coordinate system. This has the same effect as if the tracker target is directly attached to the VR device itself. Think of the target being attached with a sturdy iron bar to the VR device. This is the most predictable transform mode but can cause strange results if the distance between the target and the VR device is large.

This is typically used for hip or feet.

Orientation

Attaches only the target orientation to the reference coordinate system. This has the same effect as placing the tracker target at the reference position and then directly attaching it to the VR device. This literally shortens the iron bar to make the target to be located where the VR device is. As the name implies this transform is used to transfer the rotation of VR devices.

This is typically used for hands.

Orientation Reference

Similar to orientation but also applies the distance between target and reference position. This transform is complicated to explain and use. It is similar to “Full” but applies first the rotation then the position while “Full” does it the other way. This has the effect of moving the reference coordinate system before calculating the transform. You can think of this transform as using the target position as rotation pivot point.

This transform can be used for long limbs like necks or tails. Since this transform is tricky better use “Full” or “Orientation” if possible

Orientation Target

Behaves the same as “Orientation Reference”. Might change in the future.