Insert a key representing position before translation

[4610alice]

Hi all, starting to look at creating my own poses and was wondering how I would add a key frame for a body part but not including any movements. I.e only want the limb to move from that point in the time line and not from the very beginning. I guess therefore acting as another default. Would I have to copy the previous key for that body part to where I want the motion to start from?

 

Thanks for any help in advance. 

[HDiddy]

36 minutes ago, 4610alice said:

Hi all, starting to look at creating my own poses and was wondering how I would add a key frame for a body part but not including any movements. I.e only want the limb to move from that point in the time line and not from the very beginning. I guess therefore acting as another default. Would I have to copy the previous key for that body part to where I want the motion to start from?

 

Thanks for any help in advance. 

You would need to simply activate the body part that drops a key frame for it.  Just keep in mind if you are trying to move it later in the pose, you need to drop a key frame to activate it where you intend to start the movement and than later in the pose make your movement where you intend to stop it.

[MrOllyK]

Say you wanted the hip to begin moving ½ a second after the beginning of the pose, you can simply activate the key there and set the spline curve.  Jagged spline doesn't allow rebounding/inertia movement before the key unless the prior key value is different.  Other splines may introduce some movement before and/or after.  If you have moved the body part prior and want to hold it in place, you can do the same thing at the point where you want to hold it.  Not necessary to copy keys unless you have a special position, just activate the key at that point.

[4610alice]

Thanks both of you for the suggestions will try them out and let you know how I get on.

[onevision]

On 4/19/2021 at 8:54 AM, MrOllyK said:

Say you wanted the hip to begin moving ½ a second after the beginning of the pose, you can simply activate the key there and set the spline curve.  Jagged spline doesn't allow rebounding/inertia movement before the key unless the prior key value is different.  Other splines may introduce some movement before and/or after.  If you have moved the body part prior and want to hold it in place, you can do the same thing at the point where you want to hold it.  Not necessary to copy keys unless you have a special position, just activate the key at that point.

Linear (or spline as you call it) tangent is one of the most useful tangents just for that reason. The basic concept to remember is that there is no movement between identical key values, and a linear (what else?) increase/decrease between different values.

The only exception to the rule is the first key, You get a steady motion (or no motion) there even if the first key tangent is set as "smooth".

[MrOllyK]

46 minutes ago, onevision said:

Linear (or spline as you call it) tangent is one of the most useful tangents just for that reason. The basic concept to remember is that there is no movement between identical key values, and a linear (what else?) increase/decrease between different values.

The only exception to the rule is the first key, You get a steady motion (or no motion) there even if the first key tangent is set as "smooth".

Actually not entirely accurate.  There CAN be movement between identical key values if you have a non-identical value before/after the identical values and a soft/wavy spline curve.  It's hard to explain in words but you'll get end/start "rebound" movement between those values unless you use a jagged spline.  The greater the difference in values the greater the rebound movement.

[onevision]

14 hours ago, MrOllyK said:

Actually not entirely accurate.  There CAN be movement between identical key values if you have a non-identical value before/after the identical values and a soft/wavy spline curve.  It's hard to explain in words but you'll get end/start "rebound" movement between those values unless you use a jagged spline.  The greater the difference in values the greater the rebound movement.

I meant identical key values AND both key tangents set as Linear (sorry for the understatement). And nothing in between, of corse.

The same happens if the very first animation key is smooth, and the second is linear. Or the opposite: very last and second-to-last key identical, linear and smooth tangents respectively.

You may wonder why the first/last frames are special, and are the exception to the rule...

For a simple, logical reason: to allow unused keys to mantain a costant value through all the animation (you won't see any fluctuation, the limb or whatnot remains static).

In fact, if first and last key are identical and have smooth tangent, and the key value never changes in between, there's no "rebound".

Basically they are treated as Linear even if they are Smooth (or plainly ignored, you may say).

 

P,S,

Actually, I'm not so sure about the last key, need to check. But the first key acts as described.

P.P.S.

And the last too. Here's proof (pose attached):

 

Save.7z

[Syke]

3 hours ago, onevision said:

In fact, if first and last key are identical and have smooth tangent, and the key value never changes in between, there's no "rebound".

Basically they are treated as Linear even if they are Smooth (or plainly ignored, you may say).

This is true but sadly still has issues where the last key is still 'repeated' in time. I mean, it's not unsurprising - there are two keys - but it makes having smooth transitions relying on smooth tangents impossible: there will always be a 'pause'. You'll note this especially when you compare duplicating animations rather than the first and last frames repeating an animation. This wouldn't be as bad if it also didn't mean that not infrequently, where you do try to duplicate to add other variations, it can mess up the 'loop' you think you've gotten with the core loop relying on first and last frames . The bane of trying to make 'dance' animations for me 

 

The best way I've found is to try to design an animation where natural 'stops' occur... e.g. peaks/valleys/major direction changes of movement and have those finish on the first/last frames, using a flat tangent... but this works best for 'slower' crests in a way, where the flat tangent isn't unexpected in the movement in a... derivative = 0 sense.

 

Though, this is a comment not exactly directed at you as you're probably familiar with this but a note for others reading along for tips lol

[onevision]

On 5/13/2021 at 7:04 PM, Syke said:

This is true but sadly still has issues where the last key is still 'repeated' in time

Sadly, I don't get the meaning of your post. I am completely unaware of these "stops" you mention. If the first frame is copied multiple times (clearly for the purpose of obtaining a loop with "variations") and the smooth tangent doesn't work as intended, you can always force that behavior using additional keys. Speaking of loop chains, I think it's best if you remove the redundant keys with TKX_Utils before editing further the animation. Might even solve this problem you have.

[Syke]

1 hour ago, onevision said:

Sadly, I don't get the meaning of your post. I am completely unaware of these "stops" you mention. If the first frame is copied multiple times (clearly for the purpose of obtaining a loop with "variations") and the smooth tangent doesn't work as intended, you can always force that behavior using additional keys. Speaking of loop chains, I think it's best if you remove the redundant keys with TKX_Utils before editing further the animation. Might even solve this problem you have.

It's not the redundant keys - that shouldn't generally be an issue at all in this case. 

I've attached a file to clarify. It has three poses: Demo1, 2, 3:

LoopRepeat.zip

Demo 1: I've set it up to show the translation animation that finishes at the ends. To keep to consistent, I've used flat tangents so I can lock intermediate frames which don't do anything in this case with smooth tangents. You can delete these intermediate key frames and the animation won't change here. I have them here to use as a basis for Demo 2.

Demo 2: I shift the phase of the animation such that instead of starting/ending at 'ends' of the movement, it now starts in the 'middle' of the movement. If you look carefully, you'll see that in one direction, it's quite smooth but in the other, where it crosses the end/start frames, it 'pauses' ever so briefly (1/24s in fact...).

Demo 3: Just duplicating the frames in Demo 2 so you can clearly see that it works find when not finishing/starting on end/start frames, and when it is, it has this 'pause'. The only way you can kinda get around this is to set all the key frames before the finishing smooth tangent and deleting the last key frame (assuming you only have smooth tangents). I haven't done this much because it makes it really difficult to edit poses  and use them to construct others, for what should be obvious reasons, and I don't even know for sure if this is truly feasible to try and correct this, especially if you want to mix tangents.

Note that this behavior is not limited to smooth tangent finishes but is the most noticeable since that's when you typically want fluid, continuous motion. Thus, this makes something like repeating a loop of a rotating hip (e.g. my allusion to dance poses), incredibly difficult.

Now, because of this repeating frame thing, you build a pose with this base movement, but when repeating, because it behaves differently, it can mess up what you had assumed was good and you have to do tweaks on the repeat frames that are now different from your start/end frames. It's subtle and not always there but it can be quite a nuisance if you're really trying to get something to look right by observing a repeating action.

[onevision]

I'll have a look at these poses. In the meantime, I can only anticipate that when trying to change the phase of the animation, you need to be very careful as all sort of shit may happen.

I guess you changed the starting point of the base loop, and then replicated this new loop (the best way to do it). Shifting the full animation would be much more difficult, if possible at all.