How to Quickly Put Target at the Top of the Constrained Bone in Animation

wpw1221

Hi everyone!

I created an IK constraint to connect limbs, and in the setup, I placed the target directly at the top of the bone, using compression to achieve a certain perspective effect. However, I encountered a problem during the animation process. When I drag the target to other positions to move the limbs, if I drag it too far, the target takes some time to "run back" to the top position before it can start the normal compression action, causing the compression to appear very abrupt. If I key the target at the bone top every time, this issue doesn’t occur.

Because "dragging too far causes animation stuttering," and dragging too close causes the bone to "compress," I need to maintain relative accuracy every time I key the limbs. Considering that limbs are very frequently keyed, I want to ask if there is a quicker way to place the target at the top of the IK bone. Thank you very much!

Spinebot

To quickly place the IK target at the top of the constrained bone during animation, you can follow these steps:

Create a Helper Bone: Create a new bone that is a child of the constrained bone. This bone will act as a reference point for the IK target.
Position the Helper Bone: Set the local translation of this helper bone to the length of the constrained bone (e.g., if the constrained bone's length is x, set the helper bone's local translation to x, 0). This will place the helper bone exactly at the tip of the constrained bone.
Copy and Paste Transforms: When you need to place the IK target at the top of the constrained bone, select the helper bone, copy its transform (ctrl+C), then select the IK target bone and paste the transform (ctrl+V). This will move the IK target to the exact tip of the constrained bone.

This method ensures that the IK target is always placed accurately at the top of the constrained bone without manually adjusting it each time. Here is a more detailed breakdown:

Create a Helper Bone:
- Select the constrained bone.
- Create a new bone as a child of the constrained bone.
Position the Helper Bone:
- Ensure your coordinates are set to 'parent'.
- Set the X location of the helper bone to be the same as the length of the constrained bone (e.g., if the constrained bone's length is x, set the helper bone's local translation to x, 0).
Copy and Paste Transforms:
- Select the helper bone and copy its transform (ctrl+C).
- Select the IK target bone, ensure 'World' axes are selected, and paste the transform (ctrl+V).

By using this method, you can quickly and accurately place the IK target at the top of the constrained bone, ensuring smooth and consistent animations.

For more information, you can refer to the following discussions:

wpw1221

Thank you bot, but your suggestion seems a bit more complicated than just dragging the target back to the top 😃 I wonder if there is some shortcuts or something

Nate

Sorry, there currently isn't a way to restrict the target bone from going outside the range of the IK constrained bones. This could be tricky with non-uniform scale and 2-bone IK, which makes the range an ellipse. Also it wouldn't make sense when there are multiple constraints.

Usually you can just eyeball placing the target very near the maximum range.