UDK/UT3 Video Tutorials List and Support Thread

[DemoMan2]

Now that I think about it, I started building this vehicle model using Blender 2.63 so the problems may be in the .blend file. If that's the case it would explain why even the older version of the program can't translate the model correctly. Of course, it could also just be a lose nut at the keyboard issue as well. I am still pretty new to 3D modeling.

[DemoMan2]

Well, I gave Blender 2.62 and 2.61 a go and neither of them where able to fix the problem. It's probably something I did with the mesh that just sort of blew UDK's mind. BTW, I am using July 2012 UDK.

[geodav]

basically what i did was to make a sphere then uvw map, apply material/texture, add an armature with 3 bones and skinned it, then exported the mesh via the udk tools as a psk, after that i made a simple morph-target exported as psk both imported fine.
darknet thinks this could be a problem with the new bmesh system in blender which was introduced with version 2.63 atm the best thing to do is use 2.62 or register on the blender site and report the bug.

as and when i get time i'll try a more complex mesh/rig

[DemoMan2]

For what it's worth I've been having trouble importing a new vehicle skeletal mesh using Blender 2.63 & 2.64 into UDK. It seems that many of the faces just disappear. It doesn't seem to matter if I use .FBX or .PSK formats. I have no idea why this is happening.

[geodav]

ok just re-created the same mesh in blender 2.63a and did the morph, so far everything worked fine

Darknet mentioned if you have moved your mesh from 2.62 or before you might try to rebuild the armature as this could fix the problem
or the unlucky fact that the new blender mesh system breaks the old meshes in some way

[geodav]

i did a quick test last night and i couldn't get the fbx morph to load at all, i'll try some simple meshes in older blenders to where the problem started and then report it to the blender people

ok hear is what i've just tried, in 2.60a i made a sphere+rig+uvw map saved 2 files
1. Clean
2. Damage
exported using the blender Unreal Tools , the morph worked fine
using the same files it all works in 2.60a 2.61 2.62

guess i'll have to report it tomorrow when i have a bit more time

[PsychotropicDog]

looks like we need to speak to the blender people to fix the exporter but before we do that let me try something else

nope that worked fine !!!! there must be some sort of problem between blender and udk as the blender morph loads fine as a normal mesh ?

You mean as a static mesh or a seperate skeletal mesh? Err, it should load fine...
Sure there 'might' be a problem with the psk exporter, I am not ruling that out, but it concerns me that the very same behaviour happens with FBX importing - which leads me to guess that there is something odd in the way UDK handles vehicle morphs.

[geodav]

looks like we need to speak to the blender people to fix the exporter but before we do that let me try something else

nope that worked fine !!!! there must be some sort of problem between blender and udk as the blender morph loads fine as a normal mesh ?

[PsychotropicDog]

Well I was going to take a nap, but it's niggling at me, so maybe I will try FBX morphs and see if this problem creeps into them as well.

Edit:
yes, you can get this same strange behaviour with FBX morphs.
It seems to involve the 'update morphs' function that automatically crops up.
Sadly, unlike (maya2009) actorX psk's and FBX 2013 morphs that can be deleted and simply re-imported to fix, I can not get this type of work around to work with blender's psk exporter.

[geodav]

just tried with blender 2.64_RC2 and get the same problems !!!!!!

[PsychotropicDog]

The mesh was parented to the armature - empty groups, then the verts assigned. Yes I checked. a lot.
There is no other way I know to find the weights of the verts besides having them in seperate vertex groups, and 'N' properties in 3D viewport with a single vert selected also shows that vert's group(s) weights.
There is something odd going on.

tried blender 2.60a .. it doesn't like newer blends; didn't work. to test 2.60a, I will have to import as obj, rebuild the armature blah blah blah. Later.

edit: started a thread in reporting forum.

[geodav]

long question short answer, skinning problem. you get the same sort of problems with other programs.

the problem i had with blender skinning is that i find it hard to see if some verts have weights for other bones

you can also try an older version of blender, with someone elses mesh it had errors with 2.63 but worked fine with 2.6

[PsychotropicDog]

Well, I've watched all the vehicle tutorials, however I have a problem with morph targets.
As you can see, there is some undesirable vert action going on.

Edit: I moved the video to the reporting issues area.
http://forums.epicgames.com/threads/...arget-woes-psk

I tried March UDK as well.

Is it a skinning error? Unlikely. Even though it looks just like one. (I double checked in maya after an FBX export, note FBX export from blender still does not work due to armature node - it seems to crash UDK when trying to import the skeletal mesh, and comes up as invalid morph target if trying to bring in a morph)

I made a nothing changed morph, and nothing happened.

Is it a floating point error? Well, since rotation is usually handled in radians then converted to degrees (with some arcane formula involving pi) - there will be some. Since I modeled it normally then rotated it afterwards before binding, the verts not 'precisely symmetrical'. SO I went and cobbled a python script to run in blender - it doesn't rotate the object, it moves each vert one at a time. Great, it's super precise that way. And it did not solve this problem.

So... is there a problem with psk export from blender or UDK import (deprecated)? I can not find an updated or experimental version of the psk export script.

Or, is it possible the morph targets for vehicles rely on some sort of proximity - or is there some other factor involved? Like a poorly painted damage mask (which I figured only to affect textures/materials)?

Is it remotely feasible that there is something funky going on with the mesh? Like vert sort order, non manifold geometry, misaligned planets...

Possible 'solutions'
- FBX export of mesh and armature, then add the morphs in another package and export from that. I am likely to try this.
- redo the skeletal mesh and morphs in something other then blender - which would suck if the problem is still there.
- Since I once had a morph with only one stray vert, try smaller damage areas? - which is the kind of trial and error fun that makes hulk want to smash things.

[jlhill17]

Thanks! And thanks for the tip

[geodav]

sorry the rapidshare got deleted its now on gamefront
https://sites.google.com/site/ut40km.../udk-tutorials
http://www.gamefront.com/files/22336351/LandWalker_rar

have fun

ps if you change the code to use a wheeled vehicle it doesn't slide down the hills