Experimental Foot IK Fix - Project Announcement

This is the mod I've been banging my head against for the past week, and the first monthly post (for the 10th-15th).

TL;DR this mod makes legs and feet look nicer in animations by changing the position of the foot to prevent clipping. Long explanation below.

What is foot IK?

Foot IK is dynamic leg position and angle adjustment for terrain collision. It stops legs from clipping through uneven ground like hills, mountains, stairs, etc. It works alongside animations to make them look better (because clipping looks terrible).

Vanilla Skyrim doesn't have foot IK enabled on stairs, and it doesn't have foot IK enabled on running, presumably for performance/jank reasons.

What does this mod do in a nutshell?

This mod enables foot IK in the above instances where it would be disabled. So there should be a lot less clipping into terrain or architecture when running or on stairs.

But wait, what else does it add?

It enhances Foot IK by adding it for the entire foot, from the heel to the tippy toes, whereas in vanilla only the heel is counted as part of the foot IK.

You can see the effects of this change in the pictures attached.

For example, in vanilla if you're on some stairs and the heels of your feet are on the same step, foot IK doesn't do anything, even if the front half of your foot was clipping through the next step. This mod changes that so it'll properly place feet on the next step as needed to prevent clipping.

Here's a comparison image with vanilla feet and this mod off vs on.

Why did Bethesda make Foot IK so bad?

Bethesda decided to cut out the advanced options for foot IK in Havok and opted for single raycast foot IK.

This decision was probably done for console performance reasons in 2012 and it was never changed with the release of SSE/AE. That changes with this mod though.

Performance impact?

None. On a reasonably modern system (as in better than Xbox 360 specs), there should be zero performance impact going from single raycast foot IK to double.

What next?

• Fine tuning adjustments to reduce jank.

• Solution for potential z-jitter on stairs (more on this later)

• Dynamically adjusting foot IK parameters depending on terrain type, incline, worn boots, etc.

• Solution for turning off Foot IK in special cases (cough cough Ostim scenes cough cough)

• Same treatment for all creatures with foot IK (a handful).

• Maybe add Foot IK to creatures without foot IK?

Download here.