It's not really fair to say that 3Impact REQUIRES a yearly payment. There is a yearly payment for new updates, as with many engines. The update currently being worked on is to rewrite it with DX9, add FX shaders, etc, and the reason 3DRad died was because their upgrade policy was too generous.
It's not like your existing version of 3Impact ceases to work or becomes illegal to use if you don't pay. You just don't get upgrades beyond the first year unless you pay again.
It's not like your existing version of 3Impact ceases to work or becomes illegal to use if you don't pay. You just don't get upgrades beyond the first year unless you pay again.