[TArray](API\Runtime\Core\Containers\TArray)< [TPBDGeometryCollectionParticleHandle](API\Runtime\Chaos\Chaos\TPBDGeometryCollectionParticleHa-)< [FReal](API\Runtime\ChaosCore\Chaos\FReal), 3 > * > CreateGeometryCollectionParticles ( int32 NumParticles, const [FUniqueIdx](API\Runtime\Chaos\Chaos\FUniqueIdx) * ExistingIndices, const [FPBDRigidParticleParameters](API\Runtime\Chaos\Chaos\FPBDRigidParticleParameters) & Params )