KineBody Pro

Movable 3D Human Model

KineBody Pro Instructions:

(last updated 240530)

Navigating Background Videos


Users of KineBody Pro AnimTools (subscription) can import images or videos into the background of the viewing area, behind the KB skeleton, to serve as templates for creating poses. When using videos, the general approach is to find a frame containing a useful template pose, and, while the video is paused, to fit the KineBody skeleton to that pose; then seek another pose and repeat. Poses obtained from multiple video frames can be assembled into a KineBody animation (as explained in our animation tutorials).

It's important to understand that the app doesn’t provide any capability to automatically convert background videos to KineBody animations, nor can it automatically fit a pose to any individual video frame. Instead, you have to manually find useful video frames, and manually fit the poses. For more about fitting poses, please see KineBody Instructions: Pose Tracing.

This page focuses on using KineBody Pro controls to navigate among the frames of a background video. The controls include: a set of video playback controls, which appear in the lower right, whenever a video is loaded into the background (figure, below left), and a checkbox in the 'Show' subpanel, labeled ‘In Front’ (figure, below right).

The KineBody playback controls serve as an alternative to the video’s native controls, i.e., the playback button, time slider, and other widgets, that lay atop or adjacent to the video, often at the bottom edge (figure below).

KineBody Pro video controls are provided for two reasons:

KineBody Pro video playback controls appear whenever a video is loaded into the background, and disappear when the video is cleared. Here’s a brief overview:


To do this: Proceed as follows:
Find desired content, by scanning through the video Use KineBody Pro playback controls


Use native playback controls (esp: time slider)
(Click 'In Front' to enable/disable).


View/scan the video outside of KineBody Pro: in a dedicated video player, alt browser tab, etc.
Move forward/back by 1 video frame As explained in the Details, KineBody Pro doesn't provide buttons that do this directly. Instead, use the 0.01 sec time step buttons (forward or back), and watch for changes in the video, e.g. every 4 or 5 time steps, for a 24 fps video. For an example, see here.
Move to a specified time. Enter a time value, into the time box (below the Play/pause button).
Note that the timer uses cumulative seconds (with hundredths), as opposed to hours, minutes and seconds, e.g. 4 minutes, 30.31 seconds is shown as 270.31.
Use native video controls Click/tap the 'In Front' checkbox.

When 'In Front' is enabled, the video is presented with colored border and background, as described in the Details below.

Note: while working 'in front', you can't use the KineBody joystick, to move bones or joints, select bones, etc. To resume those operations, uncheck the 'In Front' box.
Resume normal kinebody pro joystick behavior
(i.e., if the joystick isn't working normally)
Uncheck the 'In Front' box
Etc: change or clear the background video (& hide playback controls) Please visit Loading a Background Image or Video.
Move or resize the background video Please visit Moving a Background Image or Video.


Appearance during In Front mode: KineBody Pro provides a couple of visual indicators, when the 'In Front' checkbox is checked: a dark purple border around the video, and a translucent light purple background, to fill the viewing area around the video (figure below). These are provided simply to reinforce that the In Front mode is enabled, espcecially when the associated checkbox is scrolled out of view.

Variable frame durations: When navigating through the frames of a background video in KineBody Pro, you can step forward or back thru time by increments as small as 0.01 sec. If you do so with a standard frame rate (e.g., 24 frames/sec), you may see the frame content changing at unequal time intervals, e.g., every 4 or 5 time steps. Here’s an example of how the frame numbers align with time values:

frame number 1 2 3 4 5 6 7 8 9
(ideal) frame start time 0 0.0417 0.0833 0.1250 0.1667 0.2083 0.2500 0.2917 0.3333
new frame content appears at 0 0.05 0.09 0.13 0.17 0.21 0.25 0.30 0.34
increment - 0.05 0.04 0.04 0.04 0.04 0.04 0.05 0.04

The second row contains integer multiples of the nominal frame duration ( 1/24 sec = 0.0417 sec). The 3rd row shows the times reachable using 0.01 sec forward steps, when the frame content is observed to change. As shown in the 4th row, the increments between these are typically 0.04, but occasionally 0.05, i.e. 4 or 5 time steps.

No framewise stepping: You may wonder why you can't simply step forward or back one video frame at a time – if you search for such buttons, you won't find any! The primary reason for this is that video players (of 2 types used in KineBody Pro) don’t have any way to access frames by number – they can only be accessed by time. You might imagine that it should be a simple matter to define a conversion between time and frame number, but it’s actually not simple. Among the complications are:

KineBody Pro avoids these problems by simply using the video player ‘as designed’, i.e., seeking frames via changing the time values.

Video positioning in background: KineBody Pro controls for adjusting the size and position of the video (discussed here), are a feature of the KineBody Pro app, not the video, and so they act on the video only while it resides in the background.