Interactive evolutionary computation (IEC) is an effective solution for problems of user subjectivity. However, a significant problem with IEC is user fatigue. IEC requires direct evaluation, and so increasing the number of generations results in increased fatigue. We previously reported a method for building a three-dimensional (3D) model using interactive evolution. Here, we propose a method of direct manipulation (DM) using IEC to reduce user fatigue, whereby direct encoding is applied to the final results during post-processing. This allowed instant changes to the shape of the final model, reducing user fatigue. This method can manipulate several parameters of 3D models in real-time. Test results show that IEC with DM is superior to IEC alone.