Collision remains after asset reimported without it

Hi. Messing around with collision meshes and interesting issue was discovered.
You can use attached max-file for experiments, it was saved in 3ds Max 2014. If you need older please let me know.

bolt.zip

So, I’ve exported asset like this:

  • selected mesh bolt_a and all 3 UCX_
  • exported Selected to FBX
  • imported into Unreal. After Alt+C it looks good

Second experiment:

  • selected mesh bolt_a and just one UCX_
  • exported Selected to FBX
  • reimported into Unreal. After Alt+C it looks good - only selected collision is visible

The most interesting part:

  • selected mesh bolt_a and no UCX_ at all
  • exported Selected to FBX
  • reimported into Unreal. After Alt+C I see collision from the last export. I expected to see no collision at all

I’m using Unreal 4.6, windows 7, 64 bit, geForce 560 with more or less fresh drivers

Hi CryShader,

A couple of things, Could you possibly provide a 2013 version of the Max file? Also can you provide an FBX version of the three test cases?

Currently my 3Ds Max is crashing on start up and I won’t be able to look at this issue fully until that is resolved by our IT department. I can get a head start though if you provide the FBX files with the different scenarios though.

Thanks!

Tim

Hello. Thanks for reply. File resaved in Max 2013. Two FBX inside too. Actually you don’t really need FBX, just export bolt_a with it’s collisions, import it and place into the scene. Reexport for example with one collision only and reimport in UE4. It will show that only one collision remained, like it should be. But export mesh only, without collisions at all, then reimport in UE4. In my case collision remains until Editor restarted.
I came from CryEngine and there was a bug with proxy not being updated until total mesh reload (delete and Ctrl+Z afterwards). Looks like collisions are cursed in some way :slight_smile:

By the way, FBX was exported with following options ON: smoothing groups,
tangents and binormals, triangulate. Exporter throwed some warnings about turned edges, but looks like it’s gone after manual triangulation in Max, so I don’t care them.

Thanks!

Hi CryShader,

Apologies for the delay.

I’ve submitted a report for this issue (UE-7551).

As a workaround you can manually remove any collision primitives that are not needed by opening the mesh in the mesh editor and selecting the primitive and hitting the delete key.

Thanks!

Tim