TransformToBoneSpace doesn't seem to work properly

Hello, i’m trying to make the head bone rotate to a certain direction in world space. The way i’ve set it up is the following:

Anim Graph:

Update Animation Event:

The result i get is a really fast spinning head that is all over the place. Since i’m using a fixed world space direction to transform, shouldn’t the resulting rotation always pointing to the same place in world space? He’s acting like i had Add to Existing instead of Replace Existing in the Modify Bone node. To replicate this issue just create a third person template project and do what i did above. Am i missing something?

Hey xlar8or,

I didn’t experiment enough to find a way to do it with replace existing, but I usually achieve “look at” functionality with Add to Existing and World Space. Generally I’m trying to get it to follow an actor, but if I want his head to aim a certain direction, here’s what my Event Graph looks like:

If you still think your behavior is a bug, we can investigate further.


Hey , thank you for replying :slight_smile: I still think it’s a bug, at least it makes sense to me that if you’re supplying a World Direction (1,0,0 for example) to the TransformToBoneSpace and you apply the rotation modifier with replace existing and bone space and use the rotation you got, he should always be looking at the same direction.

I still haven’t been able to do the look at with the way you suggested.

Please be sure to use Add To Existing and World Space. Also use the minus node to set the rotation (I just entered 45 for this example, but you can calculate the “LookAt Rotation” however you want to). This will only rotate the head left and right, you can use the same method for up and down.

Your original setup was creating a loop by referencing and changing the head bone at the same time. This is not a bug, however.

I’ll try it out and let you know. Thanks.

Hi xlar8or,

We have not heard back from you in a few days, so we are marking this post as Resolved for tracking purposes. If you are still experiencing the issue you reported, please respond to this message with additional information and we will offer further assistance.