About Moving?

[zero16832]

I'm not sure I understand what you're trying here... unless your floor has friction or you're using velocity damping, or some other external force is slowing the softbody down, it should simply keep moving once you've added a force/acceleration to it.

This already happens in the game: once I press the screen the softbody just keeps moving forward even after lifting the finger, as no forces are acting to slow it down.

Is this what you want? in that case, there's no need to do anything in Update(). Inertia will keep the softbody moving. If you want the softbody to have a "base" velocity, just giving it an impulse at the start is enough. Again, assuming there's nothing slowing it down.

It's my fault. I've got friction on the floor。

other question it:

How can I limit softbody speed(use addForce)?

How can I slow down the softbody speed?