Bullets don't move in a sine wave. Sine waves are periodic. They move in a parabola :) See above. However, calculating the speed every frame due to speed reduction due to air resistance would be an
Originally posted by Silvercord
I don't entirely understand what you mean, but if you are talking about having it move in a sine wave and actually calculate its speed per second then I think it's a waste of calculations. The doom3 engine actually does something like this though, not the sine wave part, but the bullet is treated as a real particle and can reflect off of hard surfaces...when bullets go through smoke, the smoke actually spirals, pretty neat eh?