Unity Animation Controller and walking diagonally keeps switching between the two diagonals?

Question

Using Unity 2019.4.1f1 Personal.

I have the above Animation Controller. When only walking in one direction at a time and when you stop you stay facing that direction, this works as planned.

All of the transitions do not have an exit time and have a fixed duration of 0. I don't know what info to give as this is the first time I've used animation. Let me know and I'll add relevant details.

Here's my update function that updates the variables in the animator:

void Update() {
  float h = Input.GetAxisRaw("Horizontal");
  float v = Input.GetAxisRaw("Vertical");

  animator.SetFloat("Horizontal", h);
  animator.SetFloat("Vertical", v);

  if (Mathf.Abs(v) < Mathf.Abs(h)) {
    // flips the renderer to reuse other handed image
    spriteRenderer.flipX = h > 0;
  }

  // no actual movement until I figure this out
}

What I'm experiencing that I want to fix is when running diagonally:

It seems that when walking diagonally then the animator variables for Horizontal and Vertical are both either 1 or -1 and this causes the alternating of the sprites. What I'd like to happen is that the state machine would deterministically pick either N/S sprites or E/W sprites when moving diagonally. Turning on "Can Transition To Self" seems to properly pick a direction and stick to it but it fails to animate when only moving in a single direction. It looks like it's constantly transitioning to itself which starts over the cycle so I've left that unchecked on all transitions.

I'm not sure what the best way to fix this is. Most attempts I've tried so far complicate the state machine to the point it's unmaintainable. I also couldn't find anything about introducing priorities in a way that fixed the jitter.

What's the idiomatic Unity way to achieve clean diagonal movement in 2D?

Answer 1

The cause

Now you have selected that walk in some direction can be triggered from Any State. Thus, if you have vertical = 1 and horizontal = 1 in WalkingNorth state, your transition to WalkingEast is triggered (it meets the condition for horizontal = 1) and vice versa (transition to WalkingNorth is triggered when in WalkingEast state because of vertical = 1).

Solution

Consider changing your animation state transitions, so that Entry points to IdleSouth - this will be your initial state. Then, make transitions from every Idle_ state to every Walking_ state based on triggers. Leave Walking_ -> Idle_ transitions intact. This will prevent you from going from WalkingNorth to WalkingEast when horizontal = 1 and vertical = 1.

Answer 2

You can add a condition as when any one of the input is not 0 then randomly assign a value to the animator.

If(h==1){ If(y==1){ Anim.SetFloat("Horizontal",0); Anim.SetFloat("Vertical",1); }else if(y==-1){ Anim.SetFloat("Horizontal",0); Anim.SetFloat("Vertical",-1); }}

Same could be done with h = -1