How do i prevent cycle drift?

[peter wassink]

Hi,
I'm trying to create a walk, using "Cycle Interpolation" set to additive cycle. The character is not "in place" but actually moving forward.
I created the poses for a complete cycle and it looked fine, but when i set the animation to cycle, the character starts displaying a 'drift' meaning an incremental deviation on each cycle on some of its parts.
i suspect it is caused by slight deviations in bone position between the poses in the start (the absolute frame i point to in the Cycle) and end frame of the cycle.

How to prevent this?

i thought it could be prevented by using an exact copy of the bone keys from the frame i cycle back to.
but how to do this?
Any tips and tricks in how to hunt down the bones/keys that cause the problem?

how do you copy a pose and reposition it to the new position in the walk?
if i select/ highlight all the bones i cannot move them to a new location.
i had created an screenshot to illustrate , but the forum doesn't allow adding an image

[slowtiger]

The first thing I do in a cycle is copying the bone keys on #1 to the 1st frame after the cycle - repeatedly, if I make adjustments on #1 later. This is easy as long as everything is in one bone layer.

When my cycle consists of several layers, and keys in several channels, I double-check each channel if 1. I set the cycle 2. I set the cycle to the same frame number each. This became much easier since Moho allowed to select more than one layer and show all channels.

[peter wassink]

Hi Markus, Thanks for responding.
I have a single bone layer anim.

What do you mean with 'copying the bone keys on #1 to the 1st frame after the cycle'
For arguments sake say you have an 8 frame anim you want to cycle:
you copy the bone keys of frame 1 to frame 9, then you set the bone keys on that frame 9 to cycle 'absolute' to frame 2 (because 9=1)
this works fine for a static cycle.

but when the cycle moves you need to adjust the position of the character on frame 9 to match up and continue from frame 8 and this is where my trouble starts.
because i'm not sure how to do this.
i tried only adjusting the main/motherbone to shift the position horizontally using the shift key and that seemed to help drift on the body,
but i couldn't get the pinbone on the feet to a position to have them cycle without drift
is there a way to shift the position of a selected character without disturbing the relative positions of all its bones?
you could maybe using the layer? but i tried that too and ran into other issues...

how do you re-use pose 1 on frame 9 without the walk drifting?
surely this is a very common scenario, but i havent found a tutorial addressing this yet

[slowtiger]

Ah, I see - or I think I do ...

1. Use relative cycling.
2. For the forward motion, I usually use Layer transform, but translating the root bone should do as well. Same cycle length, only this is set to relative and additive.

This works nicely for me, but I only use rotational bone movements and no pinbones. If I have an element which stays on the ground while the character moves on, I set it to step on #1 and on #9 (in your example) to relative and additive cycle again.

[Víctor Paredes]

This tutorial could help you: