At universities, we observe a great range of variation in previous knowledge and decreasing mathematical competences of students -- partly due to less limited qualification rules at universities in Germany. To address the challenges which arise by teaching very heterogeneous student groups we use e-tutorials as an addition to traditional classroom teaching. We show how virtual 3D rooms should be constructed for the purpose of e-tutorials. Based on our experience we discuss advantages and limitations using virtual 3D rooms in university teaching.