  We present a powerful new tool to analyse and disentangle the 3-D geometry
and kinematic structure of gaseous nebulae. The method consists in combining
commercially available digital animation software to simulate the 3-D structure
and expansion pattern of the nebula with a dedicated, purpose built rendering
software that produces the final images and long slit spectra which are
compared to the real data. We show results for the complex planetary nebulae
NGC 6369 and Abell 30 based on long slit spectra obtained at the San Pedro
Martir observatory.
