Fixing joint axis orientation

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If you build your joint chain and then decide

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you want to change the orientation of the joints,

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you don't need to rebuild everything.

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You can use another tool to help.

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Let's build the joint chain again

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and close

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X.

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Let's imagine you're building the skeleton and you need to reposition the joints.

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So let's move this to here

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and this here

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maybe down slightly too

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and move this up here.

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As you can see, manually moving, the joints has broken the orientations.

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So each axis is now misaligned and no longer points to the next joint.

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So essentially the rotations won't work as we would expect.

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You see,

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we've lost the nice twist we had.

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It's not an issue though.

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All we need to do is go to skeleton orient joint and open the options.

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As you can see, this is exactly the same as a section we had in the create joint tool.

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I'll just reset it.

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So you see, we have the same options here to control where each axis will point.

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We can tell the tool to also affect all the Children of the selected joint.

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So the other joints in the chain,

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if I apply this. Now

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the orientations are corrected using the settings in the tool as a guide.

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So X is now pointing down the joint again

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and Y is pointing up,

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twist is fixed.

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It works here too because we told it to also update the selected joints. Children,

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we can also completely change this setup if we like.

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So let's switch to Y being down the joint

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and we will leave ZED pointing up

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that's updated.

02:01

Good.

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As you can see, it's dead easy to correct the orientations. If you need to,

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the only joint it won't affect is the last joint in the chain.

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Simply because that has nothing to point towards

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what we can do with this though is instead

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tell it to match the previous joints orientation.

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This is essential if this were to be a wrist joint. For example,

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all we need to do is enable orient joint to world again

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and apply that

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because this is already a child of a joint,

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it will just inherit its parents' orientation.

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So that now matches this one's orientation.

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OK. Let's close that

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if you did want the end joint to have a different orientation,

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simply create a temporary child to that joint,

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fix the orientation

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and then delete the temporary joint.