Character looking, Multi-aim with neck and torso adjustment results in "inaccuracy".

Unity Engine
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1

I’m currently attempting to make a “Character looking” constraint setup for my character here. Which includes not only head looking but eye looking. This all works solid, but then i felt the neck and upper spine bone could use some mild rotation too to be more lifelike.

This causes the look aiming to have some inaccuracies, how can i resolve this?

Correct looking without neck and torso movement
tightpossiblebrontosaurus

Incorrect or “Overshooting” looking with neck and torso movement. Note how the eyes aren’t looking at the camera and instead looking past it.
achingdistantalaskankleekai

I have tried using both multi-rotation constraint and chain IK (The SpineTurn object) with the same results.

Here’s how my constraint setup looks.
5218106--519920--upload_2019-11-27_1-50-1.png

To explain a bit the head is not directly using the aiming it is instead a damped track of a child empty object.

5218106--519923--upload_2019-11-27_1-51-19.png
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This is so the eyes follow faster than the head, and also for more realistic movement overall. there’s no native damped setting for the aiming script alone it seems.

The eyes simply aim at the target

5218106--519926--upload_2019-11-27_1-52-50.png
5218106--519926--upload_2019-11-27_1-52-50.png1282×265 19.6 KB

The neck and spine bone with use chain IK or multi rotation like above with a reduced influence.

If not for the over shooting of the eyes this would all be perfect.

2

Looks like a doubled offset due to incorrect constraint evaluation order ie. the eye aim constraint evaluates, then the spine evaluates, offsetting your eyes after they’ve been aimed at the camera. If you move the eye constraints beneath the spine constraints (in your rig hierarchy), the eye aim constraint will be evaluated after the spine and it should all work.

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3

Oh wow i didn’t know the order of objects was important :open_mouth:

That does seem to have fixed it! Awesome!

EDIT: Wait i might be mistaken

4

Ok so the problem the order makes is if the spine movement is supposed to reference the head movement, if the spine movement is processed first it doesn’t seem to read the head movement at all (even with chain IK).

If i place the spine after the head but before the eyes it seems to work ok for the eyes but not the head.

i’ll dig into it more…

5

I decided to just make the neck and spine also aim constrains with reduced influence.

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