How to corectly rig/export skeletal mesh from Blender to UE4

I’m trying to make a ragdoll in UE4. I created and rigged a character in Blender and exported it as an FBX file.

First off, UE4 failed to create physics asset, because some bones were to small, even though all the bones are farely big (bigger than the character from premade projects). So when I manualy created the physics asset, all the bones just bunched up together and it was going all over the place, even when I turned off collision between bones.

Then I tryed to delete all the bone collision boxes except lower body and upper body. And when I started the simulations, the upper body flew about 100m up in the air an it stayed there, rigidly attached to the lower body.

Also I noticed, that when I view the skeleton in Persona and try to rotate individual bones, it takes multiple whole turns to rotate bones even a little bit. I don’t know if that has to do anything with the problem, but it probably does.

Do I have to do some extra steps in Blender? Also, I don’t know what exactly it is I have to avoid in Blender (like maybe bones that are attached but not connected).

Thank you for any help :slight_smile:

I finaly got it!

I Blender, under the scene settings, there is a scale option in the Units section. For the skeleton to work properly, you have to set scale to 0.01.

I knew you should do that before, but I thought it’s not necesery and I just kina worked around it. It still worked fine with static meshes.

Anyway, this resolved all my issues. There is no more “bone size too small” error, the bones rotate just fine in Persona and ragddoll works much better now (still had to change it a bit).

I hope you’ll find this useful if you have similar problem.

This fixed my error, so I just want to give some specifics for others who are looking for a solution. I am using Blender 2.77 with the 7.4 FBX binary export and when I exported my skeletal mesh to UE4 it was huge (6000 units tall) and moving the bones in Persona did not move the mesh. As soon as I went back into the FBX export options in Blender and set the Scale from 1.0 to 0.01 it imported into UE4 perfectly and now the mesh moves with the bones. This is a strange error, but my guess is UE4 has some kind of size constraint. I also tried export to UE4 from Blender 2.68 and it did NOT need the scale set to 0.01 to work.