Blender to Unreal Scale Fix for Attached Assets

so if you work with blender and unreal and you've ever seen anything like this where you have a normal sized mesh with a normal scale on the skeleton and you go to attach something to the skeleton like a preview asset if you ever see anything like this i'm going to show you how to fix that so in blender i exported the mannequin from unreal i reimported him into blender i set him up with a new rig and what i'm now going to do is i'm going to export him from blender back into black back into unreal and we'll see what happens so back in unreal we go to import the file that we just exported using all the default settings the mesh that just imported we drag him into the world and he looks fine his scale is at one if we open up the mesh asset we check the imported uniform scale the import uniform skill is also one we check the skeleton tree everything here looks normal but if we go to his hand and we add a socket and in that socket we attach this lamp what you're gonna see is that the lamp is scaled up by a factor of a hundred and so what's going on now if you've had this problem you've probably done some digging and you probably found out that there's um a unit conversion issue between blender and unreal where blender is measuring everything in meters and unreal measures everything in centimeters so there's a scaling factor of a hundred that happens when going from one piece of software to the other the problem is that in blender we didn't have to do anything when we exported we didn't have to do anything with any of the units all we did is we just selected our mesh and we exported everything and then re-imported unreal which is kind of weird because in unreal since there is a unit conversion issue he shouldn't be this size since we didn't have to do anything regarding the units and the reason why he looks normal is because inside of the skeleton on the root bone of the skeleton if you look at the scale you see that they account for this unit conversion inside of the transformation on the root bone of your skeleton which is then propagated to all child bones which then winds up with a scale factor of 100 on that hand socket that you just added and to show this if we went to the hand socket and we then scaled everything by 0.01 that mesh now looks totally normal again so now how do we fix this well in blender what you want to do is you want to we need to scale the whole model up the armature and the model itself all of that needs to be scaled up while still meaning all the same proportions and nothing breaking and what we need to do is we need to scale everything up by a factor of a hundred the problem of course is that if you just select the armature and you scale that up by a hundred you now have a hundred scale on the armature itself which would carry over to unreal if we were to export like this so we need to apply the scale if we apply the scale the entire rig breaks so now the bones inside of this skeleton are all over the place so i undo that and i'm also going to undo the scale up of the armature so now what we'll do is instead of scaling up the armature we can go select the armature go into pose mode select the root bone of your armature and scale that up by 100 and i'm going to adjust the view clipping so now that now that the root bone is scaled up it has the scale of 100 applied to it but we're going to need to freeze we need to freeze the transforms on the root bone so that it receives a scale of one because if we export it like this we'd have the exact same problem so if we selected it and went to pose apply apply poses rest pose now the mesh disappears i think what happened is it got scaled i think it got scaled up by a factor of 100 and now it's outside of the clipping region but so now we have a problem where the mesh will scale up so what we need to do is exit pose mode go back into object mode select the mesh alt p and clear and keep transformation so that he no longer has the armature applied to him in the modifiers tab for the mesh find the armature modifier and control a on top of that to apply it now select the armature again go into pose mode again select the root bone now go to pose apply apply poses rest pose and that resets the scale back to one now go back into object mode select the mesh select the armature control p and parent and now if we go back and we try to animate this character again everything is normal so now after we've scaled up the model there's one last thing that we can do to make things easier is if we were to take the model in the format that it said now and import it into unreal we would have to import it with a uniform scale value of 0.01 but in blender if we change the unit scale here to 0.01 then we do not have to do that just remember for anything that you model that it is going to be in it is now going to be modeled in centimeters as opposed to meters so now we select everything export and we come back into unreal and we reimport so now with the new reimported model we take a look at the skeleton the root no longer has that scale applied to it if we go down to the hand bone we have the old 0.01 scale applied so we just change this back to one and now the preview asset the lamp preview asset in the hand looks totally normal and that should solve your issue that solved it for me

Channel: John Savage

Views: 4,853

Keywords: blender, unreal, ue5, ue4, unreal engine, scale, preview asset, fbx

Id: x_S5Poo2o1o

Length: 8min 51sec (531 seconds)

Published: Thu Jul 14 2022