  We simulate shock propagation in a wide range of core-collapsing
presupernovae: from compact WR stars exploding as SNe Ib/c through very
extended envelopes of the narrow-line SNe IIn. We find that the same physical
phenomenon of radiating shocks can produce outbursts of X-ray radiation (with
photon energy $3kT \sim 1$ keV) lasting only a second in SNe Ib/c, as well as a
very high flux of visual light, lasting for months, in SNe IIn.
