Author: user:AnomalousUnderdog
Description
A smoothed TrailRenderer meant for melee weapons of animated 3d models. Based on TimeBasedTrailRenderer by Forest Johnson (Yoggy) and xyber.
The MeleeWeaponTrail in action.
Usage
Attach the MeleeWeaponTrail script to the bone of your 3d model where the weapon is mounted. Add a child game object to that which designates the tip of the weapon, and assign the values in the inspector. I've included a helper script to tell when the MeleeWeaponTrail should emit or not based on the animation's frames.
Uncomment "#define USE_INTERPOLATION" to smooth out the trail but note you need the Interpolate script present in your project to use it.
Use this texture as a template:
C# - MeleeWeaponTrail.cs
//#define USE_INTERPOLATION
//
// By Anomalous Underdog, 2011
//
// Based on code made by Forest Johnson (Yoggy) and xyber
//
using UnityEngine;
using System.Collections;
using System.Collections.Generic;
public class MeleeWeaponTrail : MonoBehaviour
{
[SerializeField]
bool _emit = true;
public bool Emit { set{_emit = value;} }
[SerializeField]
float _emitTime = 0.00f;
[SerializeField]
Material _material;
[SerializeField]
float _lifeTime = 1.00f;
[SerializeField]
Color[] _colors;
[SerializeField]
float[] _sizes;
[SerializeField]
float _minVertexDistance = 0.10f;
[SerializeField]
float _maxVertexDistance = 10.00f;
[SerializeField]
float _maxAngle = 3.00f;
[SerializeField]
bool _autoDestruct = false;
#if USE_INTERPOLATION
[SerializeField]
int subdivisions = 4;
#endif
[SerializeField]
Transform _base;
[SerializeField]
Transform _tip;
List<Point> _points = new List<Point>();
#if USE_INTERPOLATION
List<Point> _smoothedPoints = new List<Point>();
#endif
GameObject _o;
Mesh _trailMesh;
Vector3 _lastPosition;
Vector3 _lastCameraPosition1;
Vector3 _lastCameraPosition2;
bool _lastFrameEmit = true;
public class Point
{
public float timeCreated = 0.00f;
public Vector3 basePosition;
public Vector3 tipPosition;
public bool lineBreak = false;
}
void Start()
{
_lastPosition = transform.position;
_o = new GameObject("Trail");
_o.transform.parent = null;
_o.transform.position = Vector3.zero;
_o.transform.rotation = Quaternion.identity;
_o.transform.localScale = Vector3.one;
_o.AddComponent(typeof(MeshFilter));
_o.AddComponent(typeof(MeshRenderer));
_o.renderer.material = _material;
_trailMesh = new Mesh();
_trailMesh.name = name + "TrailMesh";
_o.GetComponent<MeshFilter>().mesh = _trailMesh;
}
void OnDisable()
{
Destroy(_o);
}
void Update()
{
if (_emit && _emitTime != 0)
{
_emitTime -= Time.deltaTime;
if (_emitTime == 0) _emitTime = -1;
if (_emitTime < 0) _emit = false;
}
if (!_emit && _points.Count == 0 && _autoDestruct)
{
Destroy(_o);
Destroy(gameObject);
}
// early out if there is no camera
if (!Camera.main) return;
// if we have moved enough, create a new vertex and make sure we rebuild the mesh
float theDistance = (_lastPosition - transform.position).magnitude;
if (_emit)
{
if (theDistance > _minVertexDistance)
{
bool make = false;
if (_points.Count < 3)
{
make = true;
}
else
{
//Vector3 l1 = _points[_points.Count - 2].basePosition - _points[_points.Count - 3].basePosition;
//Vector3 l2 = _points[_points.Count - 1].basePosition - _points[_points.Count - 2].basePosition;
Vector3 l1 = _points[_points.Count - 2].tipPosition - _points[_points.Count - 3].tipPosition;
Vector3 l2 = _points[_points.Count - 1].tipPosition - _points[_points.Count - 2].tipPosition;
if (Vector3.Angle(l1, l2) > _maxAngle || theDistance > _maxVertexDistance) make = true;
}
if (make)
{
Point p = new Point();
p.basePosition = _base.position;
p.tipPosition = _tip.position;
p.timeCreated = Time.time;
_points.Add(p);
_lastPosition = transform.position;
#if USE_INTERPOLATION
if (_points.Count == 1)
{
_smoothedPoints.Add(p);
}
else if (_points.Count > 1)
{
// add 1+subdivisions for every possible pair in the _points
for (int n = 0; n < 1+subdivisions; ++n)
_smoothedPoints.Add(p);
}
// we use 4 control points for the smoothing
if (_points.Count >= 4)
{
Vector3[] tipPoints = new Vector3[4];
tipPoints[0] = _points[_points.Count - 4].tipPosition;
tipPoints[1] = _points[_points.Count - 3].tipPosition;
tipPoints[2] = _points[_points.Count - 2].tipPosition;
tipPoints[3] = _points[_points.Count - 1].tipPosition;
//IEnumerable<Vector3> smoothTip = Interpolate.NewBezier(Interpolate.Ease(Interpolate.EaseType.Linear), tipPoints, subdivisions);
IEnumerable<Vector3> smoothTip = Interpolate.NewCatmullRom(tipPoints, subdivisions, false);
Vector3[] basePoints = new Vector3[4];
basePoints[0] = _points[_points.Count - 4].basePosition;
basePoints[1] = _points[_points.Count - 3].basePosition;
basePoints[2] = _points[_points.Count - 2].basePosition;
basePoints[3] = _points[_points.Count - 1].basePosition;
//IEnumerable<Vector3> smoothBase = Interpolate.NewBezier(Interpolate.Ease(Interpolate.EaseType.Linear), basePoints, subdivisions);
IEnumerable<Vector3> smoothBase = Interpolate.NewCatmullRom(basePoints, subdivisions, false);
List<Vector3> smoothTipList = new List<Vector3>(smoothTip);
List<Vector3> smoothBaseList = new List<Vector3>(smoothBase);
float firstTime = _points[_points.Count - 4].timeCreated;
float secondTime = _points[_points.Count - 1].timeCreated;
//Debug.Log(" smoothTipList.Count: " + smoothTipList.Count);
for (int n = 0; n < smoothTipList.Count; ++n)
{
int idx = _smoothedPoints.Count - (smoothTipList.Count-n);
// there are moments when the _smoothedPoints are lesser
// than what is required, when elements from it are removed
if (idx > -1 && idx < _smoothedPoints.Count)
{
Point sp = new Point();
sp.basePosition = smoothBaseList[n];
sp.tipPosition = smoothTipList[n];
sp.timeCreated = Mathf.Lerp(firstTime, secondTime, (float)n/smoothTipList.Count);
_smoothedPoints[idx] = sp;
}
//else
//{
// Debug.LogError(idx + "/" + _smoothedPoints.Count);
//}
}
}
#endif
}
else
{
_points[_points.Count - 1].basePosition = _base.position;
_points[_points.Count - 1].tipPosition = _tip.position;
//_points[_points.Count - 1].timeCreated = Time.time;
#if USE_INTERPOLATION
_smoothedPoints[_smoothedPoints.Count - 1].basePosition = _base.position;
_smoothedPoints[_smoothedPoints.Count - 1].tipPosition = _tip.position;
#endif
}
}
else
{
if (_points.Count > 0)
{
_points[_points.Count - 1].basePosition = _base.position;
_points[_points.Count - 1].tipPosition = _tip.position;
//_points[_points.Count - 1].timeCreated = Time.time;
}
#if USE_INTERPOLATION
if (_smoothedPoints.Count > 0)
{
_smoothedPoints[_smoothedPoints.Count - 1].basePosition = _base.position;
_smoothedPoints[_smoothedPoints.Count - 1].tipPosition = _tip.position;
}
#endif
}
}
if (!_emit && _lastFrameEmit && _points.Count > 0)
_points[_points.Count - 1].lineBreak = true;
_lastFrameEmit = _emit;
List<Point> remove = new List<Point>();
foreach (Point p in _points)
{
// cull old points first
if (Time.time - p.timeCreated > _lifeTime)
{
remove.Add(p);
}
}
foreach (Point p in remove)
{
_points.Remove(p);
}
#if USE_INTERPOLATION
remove = new List<Point>();
foreach (Point p in _smoothedPoints)
{
// cull old points first
if (Time.time - p.timeCreated > _lifeTime)
{
remove.Add(p);
}
}
foreach (Point p in remove)
{
_smoothedPoints.Remove(p);
}
#endif
#if USE_INTERPOLATION
List<Point> pointsToUse = _smoothedPoints;
#else
List<Point> pointsToUse = _points;
#endif
if (pointsToUse.Count > 1)
{
Vector3[] newVertices = new Vector3[pointsToUse.Count * 2];
Vector2[] newUV = new Vector2[pointsToUse.Count * 2];
int[] newTriangles = new int[(pointsToUse.Count - 1) * 6];
Color[] newColors = new Color[pointsToUse.Count * 2];
for (int n = 0; n < pointsToUse.Count; ++n)
{
Point p = pointsToUse[n];
float time = (Time.time - p.timeCreated) / _lifeTime;
Color color = Color.Lerp(Color.white, Color.clear, time);
if (_colors != null && _colors.Length > 0)
{
float colorTime = time * (_colors.Length - 1);
float min = Mathf.Floor(colorTime);
float max = Mathf.Clamp(Mathf.Ceil(colorTime), 1, _colors.Length - 1);
float lerp = Mathf.InverseLerp(min, max, colorTime);
if (min >= _colors.Length) min = _colors.Length - 1; if (min < 0) min = 0;
if (max >= _colors.Length) max = _colors.Length - 1; if (max < 0) max = 0;
color = Color.Lerp(_colors[(int)min], _colors[(int)max], lerp);
}
float size = 0f;
if (_sizes != null && _sizes.Length > 0)
{
float sizeTime = time * (_sizes.Length - 1);
float min = Mathf.Floor(sizeTime);
float max = Mathf.Clamp(Mathf.Ceil(sizeTime), 1, _sizes.Length - 1);
float lerp = Mathf.InverseLerp(min, max, sizeTime);
if (min >= _sizes.Length) min = _sizes.Length - 1; if (min < 0) min = 0;
if (max >= _sizes.Length) max = _sizes.Length - 1; if (max < 0) max = 0;
size = Mathf.Lerp(_sizes[(int)min], _sizes[(int)max], lerp);
}
Vector3 lineDirection = p.tipPosition - p.basePosition;
newVertices[n * 2] = p.basePosition - (lineDirection * (size * 0.5f));
newVertices[(n * 2) + 1] = p.tipPosition + (lineDirection * (size * 0.5f));
newColors[n * 2] = newColors[(n * 2) + 1] = color;
float uvRatio = (float)n/pointsToUse.Count;
newUV[n * 2] = new Vector2(uvRatio, 0);
newUV[(n * 2) + 1] = new Vector2(uvRatio, 1);
if (n > 0 /*&& !pointsToUse[n - 1].lineBreak*/)
{
newTriangles[(n - 1) * 6] = (n * 2) - 2;
newTriangles[((n - 1) * 6) + 1] = (n * 2) - 1;
newTriangles[((n - 1) * 6) + 2] = n * 2;
newTriangles[((n - 1) * 6) + 3] = (n * 2) + 1;
newTriangles[((n - 1) * 6) + 4] = n * 2;
newTriangles[((n - 1) * 6) + 5] = (n * 2) - 1;
}
}
_trailMesh.Clear();
_trailMesh.vertices = newVertices;
_trailMesh.colors = newColors;
_trailMesh.uv = newUV;
_trailMesh.triangles = newTriangles;
}else{
_trailMesh.Clear();
}
}
}
C# - SwooshTest.cs
A sample helper script to make MeleeWeaponTrail start and stop emitting automatically based on an animation being played. Attach this script to where your 3d model's animation component is. Assign which attack animation is used, specify the start and end frames, and attach the MeleeWeaponTrail that you created earlier.
using UnityEngine;
using System.Collections;
public class SwooshTest : MonoBehaviour
{
[SerializeField]
AnimationClip _animation;
AnimationState _animationState;
[SerializeField]
int _start = 0;
[SerializeField]
int _end = 0;
float _startN = 0.0f;
float _endN = 0.0f;
float _time = 0.0f;
float _prevTime = 0.0f;
float _prevAnimTime = 0.0f;
[SerializeField]
MeleeWeaponTrail _trail;
bool _firstFrame = true;
void Start()
{
float frames = _animation.frameRate * _animation.length;
_startN = _start/frames;
_endN = _end/frames;
_animationState = animation[_animation.name];
_trail.Emit = false;
}
void Update()
{
_time += _animationState.normalizedTime - _prevAnimTime;
if (_time > 1.0f || _firstFrame)
{
if (!_firstFrame)
{
_time -= 1.0f;
}
_firstFrame = false;
}
if (_prevTime < _startN && _time >= _startN)
{
_trail.Emit = true;
}
else if (_prevTime < _endN && _time >= _endN)
{
_trail.Emit = false;
}
_prevTime = _time;
_prevAnimTime = _animationState.normalizedTime;
}
}
