Unity & CSharp - Placing Instantiated Object in the Direction of Player

Question

So, I am making a Minecraft ripoff.
I have a raycast that hits a block. It then places a block inside of that block. I am trying to make it place next to the block in the direction the user is facing.
I got some of that figured out. I use:
Math.Round();
to round up the floats. My problem is figuring out what axis to round on. I need it to depend on the direction the player is facing to figure it out.
I tried doing a complicated algorithm to figure out which face of the collider the player is facing, but that didn't work out that well....

How do I solve this? I can't figure it out.

Answer 1

You can base it off of the normal of the surface the Raycast hits. When performing a Raycast, there is an optional out parameter that supplies information about the resulting collision, including the aforementioned normal.

Here's a brief example of how you could do this:

RaycastHit hit;
if(Physics.Raycast(new Ray(transform.position, transform.forward), out hit) {
    objectToInstantiate.transform.position = 
    hit.collider.gameObject.transform.position + hit.normal * blockSize;
}

The object will be translated from the source block by the normal of the face that is hit by the Raycast. In case you're unfamiliar, the normal is the vector perpendicular to a given face (basically, what direction it's facing)