  We apply an eclipse mapping technique using `genetically modified fire-flies'
to the eclipse light curves of HU Aqr and EP Dra. The technique makes as few
assumptions as possible about the location of accretion stream material,
allowing the emission to be located anywhere within the Roche lobe of the white
dwarf. We model two consecutive eclipses in the UBVR_c band for HU Aqr, and
four consecutive `white'-light eclipses for EP Dra, to determine the changing
brightness distribution of stream material. We find fire-fly distributions
which are consistent with accretion through a curtain of material in both HU
Aqr and EP Dra, and show that the previously assumed two part ballistic and
magnetic trajectory is a good approximation for polars. Model fits to the
colour band data of HU Aqr indicate that the material confined to the magnetic
field lines is brightest, and most of the emission originates from close to the
white dwarf. There is evidence for emission from close to a calculated
ballistic stream in both HU Aqr and EP Dra.We propose that a change in the
stream density causes a change in the location of the bright material in the
accretion stream in EP Dra.
