1

Hi!

I am trying to get mye raycast to change its direction.

          Vector 3 direction = transform.forward;
				direction.x += (Random.value - 0.5f) * spread;
				direction.y += (Random.value - 0.5f) * spread;
				direction.z += (Random.value - 0.5f) * spread;

The problem is that when the transform is looking at an axis, it adds the spread to 0 (if its pointing at the Y axis, Y is zero so it will do 0 += (Random.value - 0.5f) * spread;), so it will raycast in a straight line, instead of all directions.

Does anyone know how I can fix this?

EDIT

bulletDirection = barrelEnd.forward;
				bulletDirection.x += (Random.value - 0.5f) * shotSpread;
				bulletDirection.y += (Random.value - 0.5f) * shotSpread;
				bulletDirection.z += 0f;
				
				shotSpread += spreadAmt;

Is the code for the bulletDirection and this is how I cast the ray:

Physics.Raycast (Camera.main.transform.position, bulletDirection, out info, Mathf.Infinity, shootmask)

What happens:

[13556-straight++down.png|13556]

Looking downwards (staright at an axis)

[13557-at+an+angle.png|13557]

Looking at an angle

What I am trying to make happen:

For the bulletDirection to change so that I can get bullet spread like a real gun (like in image 2), just independant from looking at an axis or not.

4

To sum up your idea, the “perfect” shot flies along the blue “forward” line coming out of the barrel. To get some spread, move the tip of that line a little bit left/right and up/down. That method does work, and is nice since it’s very easy to visualize.

The trick is moving the barrel’s left/right (the formal term is Local Coords.) Changing x will move left/right only if you’re facing north. If you’re facing East, then changing x just moves it closer/further.

The standard Unity way to move left/right is transform.right (which is your red/x arrow.) Very common, handy trick for lots of things. Using it looks like:

bulletDir = barrelEnd.forward; // note that this is length 1
bulletDir += spread * (Random.value-0.5f) * barrelEnd.right;
bulletDir += spread * (Random.value-0.5f) * barrelEnd.up;

Note how you don’t use dot-x. It’s like you’re saying “add part of my red arrow to my blue, and just work out the proper x/y/z for yourself.”

Now, moving forwards 1 and left by 0.3 is longer than a straight-ahead shot. If you were just setting speed, that would be a problem (badly aimed bullets would go too fast.) But ray casting doesn’t care how long the direction is, so it’s fine.

2

If you are looking to make a spread like for a shotgun, here is one link:

http://answers.unity3d.com/questions/492916/shotgun-bullet-spread.html

3

Looks like gimble-lock to me. Quaternions would probably help you here, do your offset with them or axis/angle functions. Or, detect that you are looking along Y (up or down) and special-case that to use alternate code.