2d raycast null

Question

 bool dropper = false;
 RaycastHit2D hit = Physics2D.Raycast(new Vector2(x-1,y), -Vector2.up, y);
 if (hit == null){
     dropper = true;
 }
 else if (hit.transform.GetComponent<pieceControls>().NormalType != NormalPieceType.Block){
     dropper = true;
 }

I'm getting a null reference exception pointing to the else if line. What's going on here? It's only supposed to go to that line if it's not null.

Answer 1

Best Answer

Answer by Bunny83 · Apr 04, 2015 at 01:52 AM

You got something fundamentally wrong with Physics2D.Raycast. I admit that the way it works is a bit counter intuitive. Raycast will always return a RaycastHit2D. Since RaycastHit2D is a struct it can't be null since it's not a reference type.

Like you can see in the example of Physics2D.Raycast you should check if the collider field of the RaycastHit2D struct is null or not.

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ProtoTerminator · Apr 05, 2015 at 09:31 AM 0

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Ah, ok, that makes sense. Thank you.

Answer 2

Answer by Rednalreden · Apr 03, 2015 at 02:40 PM

It's probably the object thats hit which not contains the following script: pieceControls which will trigger a nullpointer.

Try to place a Debug line with the name of the hit object so you know what was hit with the raycast.

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ProtoTerminator · Apr 03, 2015 at 03:09 PM 0

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I did that, and the only thing that's ever hit is a gameobject with that component on it.

ProtoTerminator · Apr 03, 2015 at 03:20 PM 0

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 RaycastHit2D hit = Physics2D.Raycast(new Vector2(x-1,y), -Vector2.up, y);
 if (hit != null){
     Debug.Log("not null, position: " + hit.transform.position);
 }

I did that, and now it's throwing the exception to the debug line. Not every time, but sometimes.

Rednalreden · Apr 03, 2015 at 03:30 PM 0

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If it throws an nullpointer exception on hit.transform.position the only other option is that the transform component is null. Since it's an 2D object shoudn't you get the RectTransform ins$$anonymous$$d of a transform?

ProtoTerminator · Apr 03, 2015 at 03:51 PM 0

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Rect is screen space. There is no RaycastHit2D.RectTransform

ProtoTerminator · Apr 03, 2015 at 06:09 PM 0

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Every gameobject has a transform. I don't understand what's happening here.

2d raycast null

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