void CalculateTriangleTangent ( const [FSoftSkinVertex](API\Runtime\Engine\Rendering\FSoftSkinVertex) & VertexA, const [FSoftSkinVertex](API\Runtime\Engine\Rendering\FSoftSkinVertex) & VertexB, const [FSoftSkinVertex](API\Runtime\Engine\Rendering\FSoftSkinVertex) & VertexC, [TArray](API\Runtime\Core\Containers\TArray)< FVector3f > & OutTangents, float CompareThreshold )