public void Itterate(float itterateTime)
{
// ** call everytime you sample animation **
position = transform.position;
now = itterateTime;
// Add a new trail section
if (sections.Count == 0 || (sections[0].point - position).sqrMagnitude > minDistance * minDistance) {
mt_TronTrailSection section = new mt_TronTrailSection();
section.point = position;
if (alwaysUp)
section.upDir = Vector3.up;
else
section.upDir = transform.TransformDirection(Vector3.up);
section.time = now;
sections.Insert(0, section);
}
}
public void UpdateTrail(float currentTime, float deltaTime)
{
// ** call once a frame **
// Rebuild the mesh
mesh.Clear();
//
// Remove old sections
while (sections.Count > 0 && currentTime > sections[sections.Count - 1].time + time) {
sections.RemoveAt(sections.Count - 1);
}
// We need at least 2 sections to create the line
if (sections.Count < 2)
return;
//
vertices = new Vector3[sections.Count * 2];
colors = new Color[sections.Count * 2];
uv = new Vector2[sections.Count * 2];
//
currentSection = sections[0];
//
// Use matrix instead of transform.TransformPoint for performance reasons
localSpaceTransform = transform.worldToLocalMatrix;
// Generate vertex, uv and colors
for (var i = 0; i < sections.Count; i++) {
//
currentSection = sections[i];
// Calculate u for texture uv and color interpolation
float u = 0.0f;
if (i != 0)
u = Mathf.Clamp01((currentTime - currentSection.time) / time);
//
// Calculate upwards direction
Vector3 upDir = currentSection.upDir;
// Generate vertices
vertices[i * 2 + 0] = localSpaceTransform.MultiplyPoint(currentSection.point);
vertices[i * 2 + 1] = localSpaceTransform.MultiplyPoint(currentSection.point + upDir * height);
uv[i * 2 + 0] = new Vector2(u, 0);
uv[i * 2 + 1] = new Vector2(u, 1);
// fade colors out over time
Color interpolatedColor = Color.Lerp(startColor, endColor, u);
colors[i * 2 + 0] = interpolatedColor;
colors[i * 2 + 1] = interpolatedColor;
}
// Generate triangles indices
int[] triangles = new int[(sections.Count - 1) * 2 * 3];
for (int i = 0; i < triangles.Length / 6; i++) {
triangles[i * 6 + 0] = i * 2;
triangles[i * 6 + 1] = i * 2 + 1;
triangles[i * 6 + 2] = i * 2 + 2;
triangles[i * 6 + 3] = i * 2 + 2;
triangles[i * 6 + 4] = i * 2 + 1;
triangles[i * 6 + 5] = i * 2 + 3;
}
// Assign to mesh
mesh.vertices = vertices;
mesh.colors = colors;
mesh.uv = uv;
mesh.triangles = triangles;
//
// Tween to the desired time
//
if (time > desiredTime){
time -= deltaTime*timeTransitionSpeed;
if(time <= desiredTime) time = desiredTime;
} else if (time < desiredTime){
time += deltaTime*timeTransitionSpeed;
if(time >= desiredTime) time = desiredTime;
}
}
