4.18.0 seemed to cause 3 problems, two of which were fixed in 4.18.1; I think all were caused by Two Bone IK changes, though I didn’t see anything in the 4.18.1 hotfix list that appeared related.
The buggy Two Bone IK is at the end of a long Anim BP with lots of conditional bone transforms before it, some of which can modify the bones affected by the IK. I kind of doubt that this bug would be overlooked if it always failed, so I’m assuming it’s connected to the earlier bone transforms in some way.
Attached are images from the same anim BP – the two on the left are from 4.17, the two on the right 4.18.1
The top ones are with the player mesh, the bottom with the mesh not drawn. All of these images have the Enable Debug Draw flag set, but only the 4.17 images show any red IK debug lines. I’ve also clipped out the Two Bone IK call and the details panel.
I’ve taken a look at how your settings are affecting the UE Mannequin on Mac and Windows machines and am unable to see any differences between the results. Reading above it sounds like you ran into a few issues, could I get some more clarification on which issue is causing the problem you are seeing above? Also, what you are expecting verses the results that you are seeing. If you can post a repro project, I can take a look at how you have your Anim Blueprints set up, since you mention there are a lot of conditional bone transforms.
The issue seems to be the Two Bone IK not working; even with constant Effector Location and Joint Target Location inputs, turning on Enable Debug Draw under 4.18.1 draws no red debug lines, while 4.17 does. If I remove my IK nodes completely, my animations act exactly the same, so it looks like Two Bone IK isn’t doing anything in this situation.
I’ll see if I can create a simpler repro project that shows the bug.
UPDATE: I’ve found that it works if I use Component Space instead of Parent Bone Space. I’m not sure what the difference is, but it looks like Parent Bone Space might be broken.
I took another look at the issue and was able to get the red debug lines to draw after tampering with the settings some. I also tried it on OS 10.13.1 and had no issue getting them to appear. I have a few general questions as to what your settings are, however a repo project will probably be easier.
What is your Effector Location Space set to?
Is there an Effector Target set?
What are the Joint Target settings?
When you say your animations act the same, are you referring to only in the preview window?
To start debunking what is causing the issue/for the repro project, I would recommend keeping it simple and creating a clean project without all of the conditional transforms maybe as well as sending me the one with them. This will give a good starting point when check to i see if it is the Two Bone IK node itself. When I looked into it, I was only tampering the settings for the Two Bone IK node. See screenshot below but disregard the strange values/settings since I was changing everything to extremes to get more visible results/seeing if I could break it. Also, the image is using Windows, just so I could get a very rough comparison of results in order to get a better idea as to what I was looking for.
Effector is Location Space; the Effector and Joint targets are literals as shown in iksettings.png. The animations act the same in both the Preview window and when I run the game in the editor.
Have you tried using Parent Bone Space for the Joint Target?
Above you mentioned the Two Bone IK is what is causing problems (by not showing up). This is usually for use on limbs for characters, so I’m not sure how you have the asset pictured above set up and would need to see your setup in order to gain a better understanding what you are trying to accomplish. Have you run into this issue using the Unreal Mannequin in a clean project with the core functionality of your set up? If you can post a repro project I can take a look at what may be causing this.
Due to how long this thread has remained inactive I will be closing it out. If you have any further questions regarding the issue above, feel free to reopen it.
