Panning the fence (23/25)

This video is a part of the - "Create TV/Broadcast Ready Animations with Adobe Animate" series. In this series, Prof. Greg Araya from the Savannah College of Art and Design (SCAD) teaches how to create TV and broadcast ready animations with Adobe Animate. You can download Adobe Animate from https://www.adobe.com/in/products/ani....

What you learned: If you know the distance and the time it takes for a cycle to repeat, you can animate something precisely by its stage coordinates.
Determine the number of frames it takes for your walk to go from the first to the second contact. In this example, the first contact pose is at frame 1 and the second contact pose is at frame 13, which means one stride has a duration of 12 frames. The entire cycle of two strides is double that, or 24 frames.
Extend the exposure of your walk cycle and fence layers to one cycle plus one frame. In this example, it is 25 frames.
Go to the halfway point of your cycle (frame 13) and set a Keyframe on the fence layer.
Nudge the fenceposts so that the one registered to foot position on frame 1 is now foot position on frame 13.
Add a Classic Tween to the frame span between the fence’s Keyframes. It should track perfectly with the near foot.
Now you can determine the distance of the stride by subtracting the X coordinate of the fence on frame 13 from the X coordinate of the fence on frame 1. The result is the number of pixels covered in one stride. Round up or down to a whole number. In this example, it is 119.95 or 120 pixels.
To determine the distance of one complete cycle, double the stride value (two strides = one cycle). In this example, it would be 240 pixels.
With this information, we can calculate what the X position of the fence should be at frame 25. It would be the X position at frame one minus the cycle distance. Add a Keyframe at frame 25 and enter your calculated value for X in the Position Property of the Object Property panel. Apply a Classic Tween to this span as well.
The fence has moved too far behind the feet to know if the distance is correct. Go to frame 13 of the Timeline and edit the fence Symbol in place by double-clicking on it.
Once inside the fence Symbol, select the three fenceposts and alt/option-drag copies of them toward the forward foot. Register the center of the new duplicates to the foot position guide. There should now be six fenceposts in registration with each other and the stride length guide.
Back out one level of the Symbol hierarchy to the to the main stage. Delete the Keyframe at frame 13 of the fence layer. The tween span should extend to frame 25 and the fence should track with the feet for one walk cycle.
If the walk tracks at this point, we can calculate the rate of pixels per frame by dividing the number of pixels in the cycle by the number of frames in the cycle. In this example, it is 240 pixels over 24 frames or 10 pixels per frame.
At this point we have one second’s worth of fence built. We need to determine how much more fence we need to make in order to have a seamless looping effect.
Look at how much of the stage the fence currently takes up. In our example, it is roughly one third of the stage in one second. By this estimation, the fence section needs to be duplicated two more times to cover the screen, which amounts to two more seconds of time, for a total of three seconds.
Extend the exposures of your layers to the three second mark (frame 72) and then advance one more frame. We want to set a keyframe on frame 73 and not 72 for the same reason we keyframed frame 25 of a 24-frame cycle – frame 73 will be identical to frame 1, so if we trim the tween span to frame 72, it will loop seamlessly.
Now, the X position of the fence needs to be set for frame 73. Simply take the stride length (240 pixels), multiply it three, for three seconds (720 pixels), and subtract the result from the X position at frame 1. In our case, frame 1 X=615.50 and frame 73 would be -104.50.
Edit the fence symbol in place by double-clicking on it. Now we need to duplicate the fenceposts enough to fill the screen.
Turn on Snap to Object and select all the fenceposts. Alt/Option drag the selection with snapping to drag out a duplicate of the entire selection. Register the fence to itself by overlapping three fenceposts from the duplicate selection over an end of the original section. Then delete the overlapping duplicates. You should have perfectly spaced out fenceposts.
Repeat this aligned duplication of fence sections until the entire stage is covered. If your alignment is correct, you will have created an endlessly panning fence loop.
The fence at frame 1 should be identical to frame 73. Convert frame 72 of the fence layer to a Keyframe and deleted the exposures at frame 73 on all layers.
Record the rate of distance per frame somewhere in the notes layer of your walk cycle symbol.
Hide the foot position and stride length guide layers in the walk cycle Symbol.