Aim IK Offset

PeterBacall

I’ve been trying a few days to get the aim to hit in the bulls eye of the crosshair. The bullet is launched from and in the direction of the fire-point. Problem is, the fire point is positioned higher than the arm that is following the aim-ik, so the bullet never goes through the crosshair. For example:
In the Spineboy-Pro example, this is also set up wrong(?). The “rear-upper-arm” is set to follow the “aim-ik”. But the Fire Point is positioned higher than the arm, so if I would fire a bullet from the fire point it would miss the crosshair.
The further away you’d aim, the more off the bullet would go.

What’ve tried:

I could setup so the gun also rotates towards the crosshair, but if the crosshair comes close to the player it starts to look really bad (like the weapon is hanging and he doesn’t have a sturdy grip on it). Also it would be hard do manage several weapons with fire points located at different positions on the gun.
I could make the bullets launched from the fire point go towards the crosshair instead of following the direction of the fire point. But this can look weird, especially if the weapon is pointing a laser that is now tilted towards the crosshair...

Question:
How can I make so that the rotation of the “rear-upper-arm” is offset in a way it makes the fire point always aim in the center of the crosshair? Can I make this in Spine, or do I need to apply this by code in Unity?

Nate

You'd probably need to write code at runtime if you don't have a straight line from the gun tip to the target. Probably it'd be better to use the gun tip bone, so you do have a straight line. Different weapons have different projectile spawn positions, for example an over-the-shoulder bazooka versus an off-the-hip shotgun. It's not hard to manage, just get the right bone and use it to spawn the projectile.

Harald

@PeterBacall A precise aim weapon IK setup can get quite complicated when you need to accomodate for all possibilities, also think of e.g. two handed guns, and so on. If you want a working precise reference setup which is rather complicated, you could consider the Gunman asset pack. It contains a more advanced rig which covers many cases. It might be more than you need however, just correcting the bullet direction as Nate described should be sufficient for most cases.