Currently, I'm writing codes using OpenGL to render 2D and 3D models of ocean currents, temperature, salinity and so on. Since a number of numerical data involved in these models, it is hard and unreasonable to increase machine memory continuely to execute and/or improve the effects of rendering. Therefore, I'm considering to use glDeleteLists() command following glCallList() immediately to release the space. Unfortunately, it doesn't work well. Are there any other ways to carry out implementation without increasing machine memory?