This answer is based off the the method described by robertbu, an example can be found in the unity car tutorial in the skidmarks script. I have no idea and cannot find where this ‘Unity Footstep’ script is.
For my answer, here is a footprint gameObject with a mesh that gets updated by the player object. Player object tells the Footprints script where to place a footprint and what type of footprint, then the Footprints script calculates where that footprint goes, also if it is a left or right footprint, then updates the mesh information.
- create a new scene, delete the camera (first person controller prefab has a camera)
- add a terrain, set the layer to “Water”
- add a first person controller (and a directional light)
- create an empty gameObject
- name it “Footprints”
- set the position to 0,0,0
- attach the Footprints script to the Footprints object
- create a footprint material, attach it to the Footprints object
- set the terrain layer on the Footprints object to “Water”
- attach the PlayerFootprints script to the first person controller
Hit play, walk around, footprints should be left behind. These footprints are random, just to show how the player script adds the footstep, but also states what type of footstep to leave. The Footsteps script looks after the size and offset of the footprints.
Variables :
Footprints :
public var maxFootprints : int = 256; // Maximum number of footprints total handled by one instance of the script.
public var footprintSize : Vector2 = Vector2( 0.4, 0.8 ); // The size of the footprint. Should match the size of the footprint that it is used for. In meters.
public var footprintSpacing : float = 0.3; // the offset for the left or right footprint. In meters.
public var groundOffset : float = 0.02; // The distance the footprints are places above the surface it is placed upon. In meters.
public var terrainLayer : LayerMask; // the layer of the terrain, so the footprint raycast is only hitting the terrain.
PlayerFootprints :
public var footprintSpacing : float = 2.0; // distance between each footprint
Now for the scripts :
Footprints :
//------------------------------//
// Footprints.js //
// Written by Alucard Jay //
// 6/19/2013 //
//------------------------------//
#pragma strict
@script RequireComponent( MeshFilter, MeshRenderer )
public var maxFootprints : int = 256; // Maximum number of footprints total handled by one instance of the script.
public var footprintSize : Vector2 = Vector2( 0.4, 0.8 ); // The size of the footprint. Should match the size of the footprint that it is used for. In meters.
public var footprintSpacing : float = 0.3; // the offset for the left or right footprint. In meters.
public var groundOffset : float = 0.02; // The distance the footprints are places above the surface it is placed upon. In meters.
public var terrainLayer : LayerMask; // the layer of the terrain, so the footprint raycast is only hitting the terrain.
private var mesh : Mesh;
private var vertices : Vector3[];
private var normals : Vector3[];
private var uvs : Vector2[];
private var triangles : int[];
private var footprintCount : int = 0;
private var isLeft : boolean = false;
// Initializes the array holding the footprint sections.
function Awake()
{
// - Initialize Arrays -
vertices = new Vector3[ maxFootprints * 4 ];
normals = new Vector3[ maxFootprints * 4 ];
uvs = new Vector2[ maxFootprints * 4 ];
triangles = new int[ maxFootprints * 6 ];
// - Initialize Mesh -
if ( GetComponent( MeshFilter ).mesh == null )
{
GetComponent( MeshFilter ).mesh = new Mesh();
}
mesh = GetComponent( MeshFilter ).mesh;
mesh.name = "Footprints_Mesh";
}
// Function called by the Player when adding a footprint.
// Adds the information needed to create the mesh later.
public function AddFootprint( pos : Vector3, fwd : Vector3, rht : Vector3, footprintType : int )
{
// - Calculate the 4 corners -
// foot offset
var footOffset : float = footprintSpacing;
if ( isLeft )
{
footOffset = -footprintSpacing;
}
var corners : Vector3[] = new Vector3[ 4 ];
// corners = position + left/right offset + forward + right
corners[ 0 ] = pos + ( rht * footOffset ) + ( fwd * footprintSize.y * 0.5 ) + ( -rht * footprintSize.x * 0.5 ); // Upper Left
corners[ 1 ] = pos + ( rht * footOffset ) + ( fwd * footprintSize.y * 0.5 ) + ( rht * footprintSize.x * 0.5 ); // Upper Right
corners[ 2 ] = pos + ( rht * footOffset ) + ( -fwd * footprintSize.y * 0.5 ) + ( -rht * footprintSize.x * 0.5 ); // Lower Left
corners[ 3 ] = pos + ( rht * footOffset ) + ( -fwd * footprintSize.y * 0.5 ) + ( rht * footprintSize.x * 0.5 ); // Lower Right
// raycast to get the position and normal for each corner
var hit : RaycastHit;
for ( var i : int = 0; i < 4; i ++ )
{
var rayPos : Vector3 = corners[ i ];
rayPos.y = 1000.0;
if ( Physics.Raycast( rayPos, -Vector3.up, hit, 2000.0, terrainLayer ) ) // also add a layermask for the terrain
{
var index : int = ( footprintCount * 4 ) + i;
// - Vertex -
vertices[ index ] = hit.point + ( hit.normal * groundOffset );
// - Normal -
normals[ index ] = hit.normal;
}
}
// - UVs -
// what type of footprint is being placed
var uvOffset : Vector2;
switch( footprintType )
{
case 1 :
uvOffset = Vector2( 0.5, 1.0 );
break;
case 2 :
uvOffset = Vector2( 0.0, 0.5 );
break;
case 3 :
uvOffset = Vector2( 0.5, 0.0 );
break;
default :
uvOffset = Vector2( 0.0, 1.0 );
break;
}
// is this the left foot or the right foot
switch( isLeft )
{
case true :
uvs[ ( footprintCount * 4 ) + 0 ] = Vector2( uvOffset.x + 0.5, uvOffset.y );
uvs[ ( footprintCount * 4 ) + 1 ] = Vector2( uvOffset.x, uvOffset.y );
uvs[ ( footprintCount * 4 ) + 2 ] = Vector2( uvOffset.x + 0.5, uvOffset.y - 0.5);
uvs[ ( footprintCount * 4 ) + 3 ] = Vector2( uvOffset.x, uvOffset.y - 0.5 );
isLeft = false;
break;
case false :
uvs[ ( footprintCount * 4 ) + 0 ] = Vector2( uvOffset.x, uvOffset.y );
uvs[ ( footprintCount * 4 ) + 1 ] = Vector2( uvOffset.x + 0.5, uvOffset.y );
uvs[ ( footprintCount * 4 ) + 2 ] = Vector2( uvOffset.x, uvOffset.y - 0.5 );
uvs[ ( footprintCount * 4 ) + 3 ] = Vector2( uvOffset.x + 0.5, uvOffset.y - 0.5);
isLeft = true;
break;
}
// - Triangles -
triangles[ ( footprintCount * 6 ) + 0 ] = ( footprintCount * 4 ) + 0;
triangles[ ( footprintCount * 6 ) + 1 ] = ( footprintCount * 4 ) + 1;
triangles[ ( footprintCount * 6 ) + 2 ] = ( footprintCount * 4 ) + 2;
triangles[ ( footprintCount * 6 ) + 3 ] = ( footprintCount * 4 ) + 2;
triangles[ ( footprintCount * 6 ) + 4 ] = ( footprintCount * 4 ) + 1;
triangles[ ( footprintCount * 6 ) + 5 ] = ( footprintCount * 4 ) + 3;
// - Increment counter -
footprintCount ++;
if ( footprintCount >= maxFootprints )
{
footprintCount = 0;
}
// - update mesh with new info -
ConstructMesh();
}
function ConstructMesh()
{
mesh.Clear();
mesh.vertices = vertices;
mesh.normals = normals;
mesh.triangles = triangles;
mesh.uv = uvs;
}
PlayerFootprints :
//------------------------------//
// PlayerFootprints.js //
// Written by Alucard Jay //
// 6/19/2013 //
//------------------------------//
#pragma strict
public var footprints : Footprints;
public var footprintSpacing : float = 2.0; // distance between each footprint
private var lastPos : Vector3 = Vector3.zero;
function Start()
{
lastPos = transform.position;
if ( !footprints )
{
footprints = GameObject.Find( "Footprints" ).GetComponent( Footprints );
}
}
function Update()
{
var distFromLastFootprint : float = ( lastPos - transform.position ).sqrMagnitude;
if ( distFromLastFootprint > footprintSpacing * footprintSpacing )
{
// AddFootprint( pos : Vector3, fwd : Vector3, rht : Vector3, footprintType : int )
//footprints.AddFootprint( transform.position, transform.forward, transform.right, 0 );
footprints.AddFootprint( transform.position, transform.forward, transform.right, Random.Range( 0, 4 ) );
lastPos = transform.position;
}
}
Footprints source image : http://www.bytedust.com/free-shoe-sole-print-vector-design
Edited image : http://www.alucardj.net16.net/unityanswers2013/footprints_256x512.png
Complete package : http://www.alucardj.net16.net/unityanswers2013/Footprints.unitypackage
