Help with animations imported from Blender

HungryMoogle · July 4, 2022, 5:52am

Hello once more, I was wondering if anyone could help me out with the issues I’ve been having with animations I’ve imported for characters I made in Blender. I’ve done process a number of times, generally without incident but recently I’ve been having a number of issues with the animations for the last couple of characters I imported into Unreal.

With the most recent character model I’ve added, the model itself was imported without any noticeable problems:

But when I tried adding animations to the character, the animations ended up looking up like :

The strange thing is that when I initially imported the armature & mesh into Unreal, it created a animation file entitled ‘enemy_springcap_Anim’ based on the death animation for the character, which actually plays the animation properly:

Unlike the file ‘anim_springcap_ko’, which is the animation I manually imported, which instead looks like :

I just don’t know why the animation file which wasn’t created by me plays the animation correctly while the one that I did make doesn’t.

Other examples that have been plaguing the animations of the last couple of character models I’ve imported into Unreal also include the following:

The above character’s tongue is rotated in the wrong direction.

And character’s feet are messed up when they should look like :

I thought I should also point that problem has only been affecting the newest models I’ve made, as I’ve also recently created & imported a ton of new animations for the earliest character model I made & imported into Unreal and I haven’t had any incidents with the new animations I added.

As always, any help whatsoever would be greatly appreciated!

HungryMoogle · July 7, 2022, 6:27am

Can anyone please help?

AngelBieliukas · July 7, 2022, 2:17pm

Hello Hungry_Moogle!

Blender and Unreal have a couple of differences in their base behavior and that causes .fbx to sometimes have issues, but it’s nothing that can’t be fixed.
Try .

When exporting the .fbx from blender.
In the configurations of export, in “Bake Animation”

Uncheck “NLA Strips” and “All Actions”

Also, by default, in the category “Transform” I recommend:

In “Apply Scalings” = “FBX Unit Scale”
( might help you with some scaling issues that are sometimes generated in Blender’s .fbx)

And check “Apply Transform” in case there is some transform that Blender have and the .fbx can’t read properly.

Hope helps!

HungryMoogle · July 7, 2022, 6:02pm

I tried as you suggestions but it still doesn’t work.

The one thing I have noticed is error message that always appears when I to re-import an animation:

I tried looking at Unreal Engine’s official documentation for FBX Import Errors [Link] as suggested by the Message Log but I can’t make head or tails out of any and how it relates to the problem I’m having.

Animation

Mesh contains the root bone in the description, but animation does not contain that bone track. The animation data should contain at least root bone track.

Make sure if animation FBX is supposed to be for the given skeleton.

Make sure the original mesh contains same bone hierarchy as the animation.

Failed to build skeleton to create animation track.

Could not find an animation track.

Animation track length is zero. You can try different options of time options.

Exported Time: Find scene’s local start and end time

Animated Time: Find root’s animated time

Set Range: Set range of the frame

Root bone of animation does not match with the root bone of the skeleton it is importing for. Is the animation file intended for skeleton?

Animation contains duplicated bones.

Animation contains bones that are not found in skeleton.

Animation does not contain any valid animation tracks, takes, or blendshapes.

can be caused by using shearing or other forms of transforms the importer does not support. Or can possibly happen due to a math error. If the animation looks fine in Persona, you can ignore warning.

As far as I can tell the problem is specifically with the animations I’m importing and not the models themselves.

I mentioned in my initial post how the tongue of one of my models is rotated in the wrong direction. I decided to take a look inside the head of the static model to see whether was a problem with the model itself or the animations. After taking the camera inside the character’s head, I found that the character’s tongue was in its proper location, albeit culled out a bit, presumably the result of me moving the camera so close.

And has been a consistent problem across all the animations of the new character models I’ve made. The models themselves are fine after being imported but the animations always seem to have one bone that’s consistently rotated in the wrong direction.

Presumably, the reason that happening to particular model is because the bone that the main body is attached to is rotated in the wrong direction. Noticeably, the model’s eyes and feet are in the correct position while the body is not.

I also don’t understand why seems to be only effecting my newer models, as like I mentioned before, problem isn’t effecting the oldest character model I’ve imported into Unreal, the model used for the main character. At the same time I was importing the newer characters & animations into Unreal, I also imported a ton of new animations for the main character and none of them have had any problems despite using the same import settings as the newer ones.

AngelBieliukas · July 7, 2022, 6:40pm

Have you tried to activate the Root Motion option ?

In Unreal, inside the Asset Details panel in the Animation Editor check “Enable Root Motion” can fix some mistakes in the animations.

Here is the documentation about it:

Let me know if it helps.

Husky211 · July 7, 2022, 10:59pm

works for me

maybe your change the bone rotation in blender in the export panel?

HungryMoogle · July 21, 2022, 5:58am

Okay, I’ve managed to fix one issue with my animations imported from Blender, I think I’ve also managed to fix a second but the third still remains unresolved.

With the first issue, the problem was that the bone that the character model’s body was parented to shared the same name as body mesh. I don’t why causes problems but after I renamed the main body & re-imported it into Unreal, the character’s body was no longer rotated in the wrong direction. Although for some reason, the various animation preview pictures now makes the character look huge which initially had me worried that the character model’s scale had been messed up. Fortunately though, that hasn’t been the case as the character appears their proper size in-game. I’m not sure why the preview images of the character’s animations are messed up, it may be harmless but its still annoying.

As for the second issue, the second character’s tongue also shared the same name as the bone it was parented to and so like the previous issue I renamed the bone that the tongue was parented to. appears to have fixed the problem but its kinda hard to tell, as every time I try to take the camera inside the character’s head to view their tongue, the tongue appears to be partially culled out. It seems look to fine in-game but once again its kinda hard to tell since the character’s tongue is only visible briefly when their mouth is opened when they take damage. It certainly doesn’t seem to be rotated in the wrong direction like before so I think the problem is fixed.

As for the third issue, the third character’s feet still look messed up. Unlike the other two issues, one I haven’t been able to fix as the character’s feet do not share the same name as any of the bones its parented to. However, the nature of problem differs from the other two in that the other two are cases of bones being rotated in the wrong direction. With particular character, their feet are facing in the right direction, it’s just that the geometry is messed up looking.

Anyone have any ideas on why is potentially happening & how I can fix it?

HungryMoogle · July 23, 2022, 5:54pm

I really don’t know what’s going on with the remaining problem model .

After taking another look at the model I noticed that the scaling & rotation hadn’t been applied on the feet and I thought that might be what’s causing the problem. So I applied the rotation & scaling and then tried re-importing the skeletal mesh into Unreal and along with all of the animations but it ended up not fixing anything.

So if its not a problem of scaling & rotation not being applied then what’s the problem? As far as I can tell its not the same issue as the other two models as I can’t find any bones within the armature that share the same name of the foot mesh. The closest I could find are bones named ‘foot_1.L’ & ‘foot_1.R’ which aren’t the same as the feet mesh as those are named ‘foot.L’ & ‘foot.R’ respectively. I’m not sure why the bones are labelled as ‘foot_1’ as there no other bones in the armature with ‘foot’ in the name but whatever at least they’re not sharing the same name as the feet mesh.

However, I don’t think the problem is being caused by bones with the same name as part of the mesh they’re parented to as in situation the mesh of the feet are distorted, whereas the other two models that had that problem instead had body parts facing in the wrong direction.

All I can deduce is that the problem appears to an animation one as the model itself looks fine after being imported into Unreal and its only within the model’s various animations that the feet are being warped.