FBX to UDK import

JamesTKirk · May 2011

Hi guys!
I searched over forums but couldn't find straight answer, is it possible to use fbx as the only format for bringing 3dsmax models to UDK? There were random posts from people having different problems with it and no solutions.
Personally when I’m trying to import skeletal mesh to udk it seems that no smoothing groups imported. Is there a way to make it work?

jocose · May 2011

Make sure you are exporting your vertex normals (smoothing groups) in the exporter options. Its a checkbox, if its unchecked, they wont export.

JamesTKirk · May 2011

I have Smoothing groups checkbox turned on. And when I choose Import type - Static Mesh in UDK import window smoothing groups import fine. So they actually are in FBX file. Unreal just ignore them when importing as Skeletal mesh.
I can't believe I'm the only man who have this problem.

passerby · May 2011

check off implecit normals in the udk fbx import options

JamesTKirk · May 2011

You mean "explicit normals"? I tried it, but it only works when Import type set "Static Mesh".

JamesTKirk · May 2011

Ok, I've found it. It was "split non-matching triangles".

passerby · May 2011

JamesTKirk wrote: »

You mean "explicit normals"? I tried it, but it only works when Import type set "Static Mesh".

ah ya sorry, it was pretty early when i wrote that.

r4ptur3 · Dec 2011

This was recently driving me nuts and it took me quite some time to find the answer so I thought I would bump the thread.

MAYA FBX EXPORT SETTINGS:

Select the root bone, all meshes attached to the rig and then hit export selected.

Make sure smoothing groups as well as tangents and binormals are checked. Although epic claims you need to triangulate your mesh, it is not necessary to check this box. The UDK will do it for you.

TO GET HARD NORMALS IN UDK:

On import, make sure skeletal mesh --> advanced --> split non matching triangles is checked.

IF YOU GET "IMPORT FAILED" ERROR IN UDK:

Chances are you have multiple bones in your rig. Make sure skeletal mesh --> advanced --> import meshes in bone hierarchy is turned on. If this box is not checked the UDK will attempt to read your meshes as bones.

Hope this eventually helps someone -- there are so many options when exporting/importing skeletal meshes as FBX files!

Prtofdacrowd · Dec 2011

UDK will triangulate your mesh in most circumstances however it is always best to use the FBX triangulate check box in MAX's FBX export as this will do a much better job as it is a modelling package and Unreal is a fully fledged engine. If there are still problems its best to manually clean your mesh.

I usually drop my object to a mesh before export as this ports the smoothing groups a lot better in my opinion that or my smoothing group assignment has gotten a lot better in recent weeks

PeteHawk · Nov 2013

Hey guys,

Been having some issues trying to import a mates spinner model into UDK.
It looks fine in Maya, but after I've cleaned it up, made sure it was the right scale, with appropriate vertex normals, frozen transformation, deleted history and triangulated.

I'm still getting some whacky results:

monster · Nov 2013

You pretty much tried all the standard stuff.

What version of Maya? Do you have have the latest service packs and FBX plugin installed? What does it look like when you re-import into Maya?

You might be bumping into the static mesh vertex limit of 65K. http://udn.epicgames.com/Three/FBXStaticMeshPipeline.html#General%20Setup

PeteHawk · Nov 2013

Importing it back into Maya is completely fine, same results as shown in my previous post.
I'm using Maya 2014 service pack 2. I've tried different FBX file formats (2014/2013/2012) all of which were binary. And I am sitting around 35,000 tris

monster · Nov 2013

Couldn't send you a PM, but if you still want help, PM me and we can dig into it.

haiddasalami · Nov 2013

Have you checked for non-manifold geo? Maya is quite notorious/easy to create that stuff

big_beluga · Nov 2013

Sharing my skeletal mesh FBX export/import settings. Hope this helps.

PeteHawk · Nov 2013

Sorry about that monster, I thought I had fixed my PM restrictions.

I have looked into non-manifold geometry, cleaned is up a little, not too many problems. Do N-gons cause problems? I'm only presuming 'no' because I end up triangulating it all anyway.

and thanks beluga for sharing that, it looks like we have slightly different export/import options but I did follow it as much as I could:

Something to consider, my UVs are showing up fine within the file, but just not on the mesh. It turns black when I add the material:

monster · Nov 2013

The screenshots show that you are over the VERTEX limit of 65K. This is not the number of vertices in Maya, it's after they've been split by UVs and normals. I've never bumped into that limit so I don't know if that could be the issue. Try importing the FBX into a clean Maya scene, and then exporting it again from there.

Also make sure all your UV verts are in 0-1 space.

And maybe uncheck Remove Degenerates. It looks like the windshield was build double sided. If there are verts on top of each other they will be removed. That might be causing the fragmenting there.

PeteHawk · Nov 2013

I went and crunched those polys down hoping to reduce the vertex limit...but it says it's now around 90K vertices with about 30k tris.
Now I'm even more confused hah!

Feel free to have a look:
Spinner FBX

The good news it that I fixed the UVs, they had a 2nd channel for no apparent reason and UDK didn't like the idea.
So the textures work, it's just the geometry is a little funky

haiddasalami · Nov 2013

Try putting the whole mesh to 1 smoothing group (all soft) and import that in and see if you're vertex count changes. Basically for every hard edge the vertices are broken so you get 2 vertices while soft edge is one.

PeteHawk · Nov 2013

Eureka! I finally got some solid results. It seems like I cut down more and more on the tris until my verts went under the limit. then it worked.
Fingers crossed it stays okay.

But for now its golden, cheers guys for your help

PeteHawk · Nov 2013

PS: I'm struggling to find out why my Maya exports have increased the vert counts on all my assets...On a lot of them it's exactly double.
Check it out here on the content browser:

nubitol · Sep 2014

hello everyone, I'm sorry for jumping on this thread; I cannot start a new thread.

I'm new to UE4 and having FBX export/import issue.

when imported to UE4, some geometries were missing, although I had selected all the necessary geometries and bind joints, exported them from Maya 2014 to FBX 2013.

any hints on this issue?
thanks in advance.

r4ptur3 · Nov 2014

holy shit, i can't believe this thread kept going!

@ nubitol -- make sure your mesh is the correct scale. if your mesh is super tiny you will lose your geometry due to precision errors. Other than that, make sure you aren't importing ten billion tris. I'm not sure what the max vert count for UE4 is, but it was around 64K tris in UE3.

@ peteHawk -- do you have more than one UV set? Also, if you import your meshes with hard edges it will double or triple your very count. Make sure your mesh is smooth

FBX to UDK import

Replies