Getting started with hand keyframing
Mocap capabilities of iPi Mocap Studio lack tracking finger poses. Mainly because the resolution of input data is not sufficient for that. When it comes to hands, there is a need for employing the traditional keyframing technique in 3rd party animation software.
However, when doing keyframing over mocap data, it is very convenient to have a video reference. Why not to do this right in the mocap software, which natively deals with video? Now you can. Meet the hand keyframing feature of iPi Mocap Studio.
In iPi Mocap Studio, each key frame is actually represented by a segment of time, much like takes. Usually it occupies more than a single frame of the animation. The last frame of this segment contains a pose essential to this key frame, the key pose. Within the duration of the key frame's time segment, the pose gradually transitions from the beginning pose to the key pose. After the last frame of the key frame, the key pose continues till the beginning of the next key frame.
Timeline has got 2 new tracks — Right hand and Left hand. You use them to manage key frames for finger poses of the two hands of the model, accordingly. To insert a key frame in the current frame, you can do one of the following:
- Manually edit one of the finger bones with the Rotate tool
- Click Insert Key Frame for Right Hand or Insert Key Frame for Left Hand menu item from the context menu of the timeline
- Paste a pose data containing the finger bones rotations from the clipboard
Key frames are shown as triangles, with an apex at the beginning. You can easily move a key frame by dragging it with the left mouse button. When moved, the key frame retains its key pose in its last frame. Also, dragging the left edge of a key frame will change its duration (or, in other words, the position where the transition from the previous pose starts). Double-click on a key frame to quickly go to the last frame of a key frame, which contains the key pose.
Right click on a key frame brings up its context menu, containing items for:
- Going to the last frame (same as double click)
- Setting one of the predefined poses like fist, relaxed etc. as well as recently used poses from files
- Deleting this key frame
Managing hand pose library
You may add your own hand poses to the list of standard poses present in the context menu for a keyframe. For that, you just need to save the hand pose somewhere in a file. 10 most recently saved/loaded/applied pose files are listed in the context menu for corresponding hand. To access older poses, use Edit > Load Pose from File to Clipboard menu item — the hand pose will be automatically placed to the context menu (replacing the oldest one from 10 items).
To save a hand pose in file, do the following:
- Setup the needed pose for fingers with the Rotate tool (or copy from another hand)
- Select the appropriate hand bone (RHand or LHand)
- Hit Edit > Copy Pose of Selected Bone's Children to copy the pose of fingers to the clipboard
- Hit Edit > Save Pose to File from Clipboard to save the pose in a file
See also the video tutorial.
Transferring a pose from one hand to another
Sometimes, after you have carefully edited a pose for the hand, you realize that this pose needs to be copied or transferred to another hand. Oh, no! That's too much effort to repeat this manually, especially when you need exactly the same pose (are you creating a pose library?). We thought about this while authoring predefined poses for both hands, and included two menu items in the Edit menu. One to copy the pose in the current frame from the right hand to the left, and other — in the opposite direction.
- When using the Paste Pose within ROI command, the finger bones are not touched. Use direct manipulation with hand key frames to massively edit finger poses.
- When editing the fingers pose in the middle of an existing key frame, it is automatically split in two parts. When editing the pose in the last frame of a key frame, its key pose is changed, and no new key frame is created.
- Finger poses for the whole animation are fully recomputed based on the key frames when opening a project. If you see some "glitches" with finger poses (they do not look like poses driven by the key frames), just reopen the project.