Two bugs with “Transform (modify) bones” in an animation BP.
I have pawns where I’m trying to set rotations from array variables for upper arm, forearm, and wrist/hand for both right and left arms in the animation BP.
First, if I take the rotation and try to use the component parts (I wanted to negate pitch and yaw for the left side so it would be automagically reflected from right to left), it just reads the inputs as zeroes with a blue “NOTE” saying “info Rotation Pitch/Yaw/Roll was visible but ignored” – the values are all read as 0. If I add a recombine node so it feeds into the transform bone as a single rotator input, it works fine.
Second, no matter what I try, if I add all six transforms, it runs but will crash the next time I try to open the project with a SIGSEV, usually trying to access memory at 0x3 (probably a null pointer bug). If I only use 4 transforms, it works and doesn’t crash. It doesn’t appear to be the variables themselves – if I do just right & left upper + forearm, or just upper + wrist, it works and doesn’t crash. But if I try to do all three for both arms, it crashes the next time I try to open the project.
Added: it also crashes the spun-off thread if I try to cook the content for mac or try to package it.
Added^2: I can cook the content and package it IF I insert a local-to-component and component-to-local around the wrist/hand transforms (and it runs OK), but if I save it like that it still crashes on loading the editor.
Here are two screenshots showing the first bug. I’ve sent in some of the crashes for the second bug:
If this issue applies to the same asset, you can just send the asset once (either here or the other post.) Without your asset, it is difficult to recreate the issue you have described.
For anyone experiencing a similar issue: A corrupted blueprint file seems to have been the culprit. This was fixed by “…copying just the Anim BP and reconnecting the copy in place of the original.”
Thanks, , for communicating the steps you took to resolve the issue.
As far as I’m aware this is only a problem when you Split Struct on a Transform Bone node and has been reported as JIRA [UE-12326] (which is currently being worked on.) If you are experiencing issues with the Transform Bone node that does not have a Split Struct, please let us know. -Thanks
As an update for others coming here with similar problems, as I did on 4.11:
As mentioned, it has to do with Split Struct. Instead of using Split Struct, use a Break Node. In my case, it was a Transform struct. It’s a bug, but at least it has an easy workaround.
Also, as it seems to be common for others with the same problem, mine is a C++ project.
