I remember older versions of Cake allowed drawing velocity curves with a straight line (in piano roll, using a draw tool that changed the velocities of multiple notes in a straight line.)
  Where is this option in Sonar 8.5?
 
It's there, though, right?
 
JG

You can drag the mouse across the velocity pane of the PRV, which has its uses but is generally not terribly useful. Mostly you do that to put in some random variations, crescendos, or to limit the maximum value.
 
Other than that, I don't know of another way to draw velocities in. There's the Scale Velocity feature, which can do things such as crescendos, but it's not as simple as drawing in a line.