Hi guys. I'm new to processing, and I'm trying to program a third-person cube game. There are three problems I've come up with so far:

1. The cube only moves in one direction, i'm trying to make it so it moves whatever way the cube is facing.

2. I want the camera to follow the cube when it turns, and I can't seem to program that.

3. The rectangle I made at the very bottom of draw is not showing up, that is supposed to be my ground.

 

Here's my code:

int playerX=750;
int playerY=500;
int playerZ=0;
void setup()
{
  mouseX = 750;
  mouseY = 500;
  size(1500, 1000, P3D);
}
void draw()
{
  if (keyPressed)
  {
    if (key == 'w')
    {
      playerX=playerX+1;
    }
  }
  if (keyPressed)
  {
    if (key=='s')
    {
      playerX=playerX+ -1;
    }
  }
  background(0);
  fill(255, 255, 255);
  translate(playerX, playerY, playerZ);
  rotateY(mouseX/200);
  box(100);
  camera(0.0, 0.0, 0.0, 750, 500, 0.0, 1.0, 1.0, 0.0);
  rect(750,500,1000,1000);
}