Tip:
Highlight text to annotate it
X
Welcome back to the advanced mega rig tutorial in the leg's phase.
Now is time to see the cartonish effect of the leg's stretchiness.
In other rigs this effect is used in a way that can't change between fk and ik.
Because in most cases the character doesn't even need more than the ik part and that's enough for the character.
But here we are looking the advanced mega rig. So, in this case we'll implement all we can to the character.
And this is no exception. In this port I show you how to make the strech effect, but, also,...
...how to make it change between the fk mode and the ik mode.
Let's begin.
I go to the outliner and activate the kneepointer for selection.
Select knee and kneepointer, I asign them to the ik layer again.
I change to b-bones, select shinGEO, being that I have the GEOs active.
I extrude a bone which sticks out from the center, I call it kneeStr-Prnt. knee-stretch-parent.
Duplicate it and call the new one kneeStr. knee-stretch.
This one is going to be the son of kneeStr-Prnt in keep offset.
The parent is unparented, because this one is going to follow diferent bones.
Ok, I make a copy location and rotation to shingeo towards shinFK . Both are named fk.
Later I add a stretch to towards the kneeStr. There.
I put a copy location in the parent towards the thigh ik.
Extrude a bone from thighIk, align it with thighIK, and name it thighTipFK.
I duplicate it, scale it a little in b-bones.
ThighTipFK.001 scale it a little.
Duplicate that bone, then scale it and call it ThighTipFK-IK, that means that is going to be changing positions.
To the other duplicated bone parent it connected with thighGEO and call it thighTipGEO.
thighGEO is going to stretch with thighTipFK-IK so I add a stretch to and...
... the tipGEO is going to copy the rotation of thighTipFK-IK.
Now I select ThighTipFK and then shift+ select ThighTipFK-IK.
I give it a copy location and rotation. These are going to be the FKs. Well, like the name says it, these will change from fk to ik.
Now deactivate the ik layer to only select bones in fk.
I duplicate ThighTipFK, scale it a little.
I scale this one too.
Now, select the recently duplicated and I'm going to parent it with keep offset to the foot bone.
I test the rotation to everywhere because the rotation in fk is somewhat different to the iks'one.
Well, this is going to be the almost general foot control.
Now this ThighTipFK.001 is going to be the one controlling the ThighTipFK's rotation. So, I add a copy rotation to ThighTipFK.
To make the ankle turn better.
Select shinGEO and I take off everything except the stretch to.
I put in a copy location and copy rotation targeted to thighFK.
Ok, something's weird. And that is that the stretch to is at the top, You need to put it at the bottom to be the last to be calculated.
In fact, is still wrong, because of the copy location, so I take it out and by that it's restored.
Now I test the rotations.
I'm going to change to yzx euler for the ThighFK.
I block z and go back to test scales and the like.
The thighGEO is parented to kneeStr in keep offset.
Block everything except the location for the kneeStr.
For the toes bone I block everything except the scales and the X rotation.
And for foot, I block the location axes.
I select kneeStrPrnt and I add it a copy location towards the thighIK to copy the location of this bone.
Now to the shinGEO, I add a copy location and a copy rotation targeted to shinIK. And send the stretch to to the bottom in the hierarchy.
The same for thighGEO. I add a copy rot. and name it IK with the target in thighIK, and send the stretch to to the bottom.
Check.
I set the side view.
I turn on all the layers except the fks and I check all the bones to see if the work well in the ankle's change point.
Select thighIK-Tip and shift + thighTIpFK-IK and put to it a copy location and rotation.
And now we see that everything turns perfectly in the IKs.
Select foot-Ctl_IK, and copy the custom property fk-ik by right-clicking over the value in the properties bar...
... or in the bone's tab.
If you don't have this property it, create it. the minimim in 0.0 and the maximun in 1.0, the value in 0.0.
Select thighTip FK-IK.
Change the names of the constraints to ik.
I add a driver to the copy location ik.
I split the screen and turn it into a graph editor in drivers mode.
Put the variable in single driver, put the armature, and paste the data path and change it to averaged value.
Now I go to the copy location, to copy the driver by right-clicking over the constraint 's influence...
...and selecting copy driver.
I paste it in the copy rotation ik by right-clicking again over the influence and selecting paste driver.
Also paste it to the thighGEO's copy rotation ik, to the kneeStr-Prnt's copy location ik...
... and to the shinGEO's copy location ik and rotation ik.
And now when I slide the fk-ik slider I can change the influence of all those bones.
Select kneepointer and change the target to TighIK for the copy location. To make it point to the ik bones.
We see how they stretch with the fk bones, but not with the iks,...
...because the mechanism's iks don't know that they should stretch.
Select thighIK. In the bones tab open the Inverse Kinematics section.
There is a slider named stretch to which I set in 0.001.
Repite for shinIK.
Select knee and turn off inherit scale in the bones tab, under the relations section.
Move the mechanism bones and the helper ones to other layers to not to have to see them.
To thighTipFK.001 call it footFK_follower.
The kneeStr put it in the fk and ik layers.
At last, reach the kneepointer in the outliner to deactivate the selection option.
And like that is that I end this tutorial, see you in the next one.