Foot through the floor

[Lori Hiatt]

I am working on Exercise 5-take a walk and I'm so proud, all looks perfect 0-15. see picture.

 

Then I do the edit copy keyframe. edit paste mirrored to 20 and I get rabbit's foot going through the floor starting on keyframe #11. I don't want to fix all of this manually. What am I doing wrong? Here's a picture of #15 after pasting #20.

 

Thanks in advance.

 

Lori Hiatt

[Stuart Rogers]

What am I doing wrong?

By default the bones interpolate between keyframes using smooth splines, so as you pull CPs up, some parts of the spline may dip down, resulting in the effect you're seeing.

 

To fix this, bring up the PWS - select menu View->Project Workspace. The drag the right hand edge of the PWS to the left to reveal a timeline of your animation - by default it'll show your keyframes as little tick marks. Select the wavy coloured lines button in the bottom left of the timeline window to show the curve your bone is bone. Select one of your foot bones and you should see its curve dipping below the zero line. Select those keyframe CPs to either side of such a dip, right click on the selection and choose Interpolation Method -> Zero Slope. That should fix it.

[attachmentid=20639]

[LurkerAbove]

That's a great solution, and the shortcut on the keyboard is 7. You can select the CP in the PWS, press the 7 key, and you'll see the line change.

 

The reason this is not in the tutorial is because the tutorial suggests using more keyframes to fix the problem. This also works, and you probably should play with both solutions because each has different applications at different times.

 

So basically, you're not doing anything wrong

 

Cheers!

[Stuart Rogers]

...and the shortcut on the keyboard is 7.

I do it my way because I'm a bear of very little brain - there's only so many keyboard shortcuts I can remember!

[Lori Hiatt]

Hi,

I am trying to work with the graph solution. I did not have IK Left foot but left foot target as shown. I tried several lines and went to zero slope but nothing helped.

 

Lori

[heyvern]

This looks like one of those times when you need extra keyframes.

 

That bunny has huge, big, floppy clown feet. They are going to dip into the floor even with zero slope for the foot location.

 

You need to tweak one of the "extreme" spots by rotating the foot to bring it up. Notice that the foot is not below the floor... it is ROTATED below the floor. His heel and the null controling the foot are right where you want them.

 

A situation like this demands "human intervention".

 

It may not even require a bunch of extra keys... probably just a few at specific trouble areas.

 

-vern

[robcat2075]

If that's the Rabbit with the AM2001 rig, part of the problem may be that it doesn't really have a way to lift the heel. One has to raise the whole foot, then tilt it down and bend the toe to get the same effect, which you appear to have done.

 

In interpolating between flat foot pose and "raised heel" pose, the toe may move down faster than the foot raises, causing it to dip below the ground.

 

But without seeing your project I can't be sure .

[LurkerAbove]

Rabbit doesn't have a heel, but his toes are long.

 

You know, I cannot remember if I ran into this problem. I don't think I did. For some reason, 'Take a walk' was one of those that if you did exactly what the book told you, it worked.

 

Now the pitch, that's where the extra keyframes come in.

 

Now I think that walking for me did have a false start or two, and I had to start over. Its not too long of an exercise, and one well worth doing a few times.

 

But, if it still goes wacky, go ahead and post the project up, and I'm sure we'll be able to figure out what's up.

 

Cheers!

[Lori Hiatt]

Thanks to all. I am getting better results with adding extra keys. Didn't know if there was an easier way! I'll let you know how it goes. I used the book and the video combined step by step and it looked great until I started copying and pasting!

 

Lori

[Stuart Rogers]

I am trying to work with the graph solution. I did not have IK Left foot but left foot target as shown.

Sorry for the confusion - the screenshot came from the project I was working on at the time I wrote my reply. It's pure coincidence it showed that particular bone (it's from my home-brewed rig).