How do you do a shifty on ssx 3 for GameCube?

To perform a shifty in SSX 3 on GameCube, start by gaining some speed on a jump. As you launch off the ramp, quickly press the left or right directional button while simultaneously pressing the grab button (R). This will cause your character to shift their body sideways mid-air. Timing and positioning are key, so practice to get the angle and execution just right for a successful shifty!