RE: Hairworks Offset / Gravity Error

Hello, we have been having some issues with the integration of hairworks with UE4 versions 4.17.1 and/or versions 4.17.2.

It works fine in maya and it works fine in hairworks however when we export from hairworks into unreal that is where the hair imports at -90 offset in the x-axis, therefore the engine puts the gravity in the wrong direction automatically and there seems to be no option for us to correct this error manually. Can you please help?


The problem could be due to left/right handedness mis-match. This may be due to how the hairworks asset is exported from the content tool.

How handedness is handled can also be controlled when the asset is imported into HairWorks in the API. This is controlled via the ConversionSettings structure - and the members

EAxisHint m_targetUpAxisHint;                            //!< up axis used by the game engine that will use this asset in runtime
EHandednessHint m_targetHandednessHint;    //!< handedness of original tools that generated this asset 

This is used when the asset is read into the SDK via…

virtual Result loadAsset(NvCo::ReadStream* stream, AssetId& assetIdOut, AssetHeaderInfo* infoOut = NV_NULL, const ConversionSettings* settings = NV_NULL) = 0;

So perhaps could be worked around where the asset is read into unreal.

If its possible for you team to supply us with a test scene/hair asset that you are having problems with in the source form (ie in the content tools file format). We should be able to work out pretty quickly what the problem is and get back to you.