Particle System - set emitter's mesh via script - unity3d

How I can set particle emitting mesh in "Particle System"(Shuriken) component? Searching in google returns me tutorials only for legacy particle system.
UPD: #gamedevelopmentgerm answered to my question:
If you want to control all aspects of particle system in runtime then you must use legacy particles.

...
UP1. Oh, I see the comment below. No, you can't change mesh shape from script though once I have seen a workaround for this problem. It was something about setting up an empty mesh as ParticleSystem emission shape an then change the mesh geometry from script.
UP2. Ok, I see further details. If you want to simulate fire propagation then I recommend you to consider ParticleSystem.Emit method instead of any emission shape whatsoever. I recommend it because with ParticleSystem.Emit you will be able to control emission shape in much more flexible way.
In fact, you may use ParticleSystem.Emit to emit particles from different mesh instances as well.
using UnityEngine;
using System.Collections;
[RequireComponent( typeof( ParticleSystem ) )]
public class CustomParticleSystem : MonoBehaviour
{
#region Properties
public Mesh[] EmissionShapes;
public float EmissionShapeSwitchSpeed = 0.5f;
public float EmissionRate = 10f;
#endregion
float _shapeIndex = 0f;
float _timeToEmission = 0f;
ParticleSystem _particleSystem;
float EmissionPeriod { get { return 1f / EmissionRate; } }
void Awake ()
{
_particleSystem = GetComponent<ParticleSystem>();
_particleSystem.emissionRate = 0f;
_timeToEmission = EmissionPeriod;
}
void Start ()
{
}
void Update ()
{
_shapeIndex += EmissionShapeSwitchSpeed * Time.deltaTime;
if( _shapeIndex > EmissionShapes.Length-1 ) _shapeIndex -= (EmissionShapes.Length-1);
_timeToEmission -= Time.deltaTime;
if( _timeToEmission <= 0f )
{
_timeToEmission = EmissionPeriod - _timeToEmission;
Mesh currentShape = EmissionShapes[(int)_shapeIndex];
int triangleIndex = Random.Range( 0, currentShape.triangles.Length/3 );
int vertexIndex0 = currentShape.triangles[triangleIndex*3];
int vertexIndex1 = currentShape.triangles[triangleIndex*3+1];
int vertexIndex2 = currentShape.triangles[triangleIndex*3+2];
Vector3 v0 = currentShape.vertices[vertexIndex0];
Vector3 v1 = currentShape.vertices[vertexIndex1];
Vector3 v2 = currentShape.vertices[vertexIndex2];
Vector3 n0 = currentShape.normals[vertexIndex0];
Vector3 n1 = currentShape.normals[vertexIndex1];
Vector3 n2 = currentShape.normals[vertexIndex2];
float u = Random.Range( 0f, 1f );
float v = Random.Range( 0f, 1f );
float w = Random.Range( 0f, 1f );
float uvw = u+v+w;
u /= uvw;
v /= uvw;
w /= uvw;
Vector3 randomPosition = v0*u + v1*v + v2*w;
Vector3 normalAtRandomPosition = n0*u + n1*v + n2*w;
randomPosition = this.transform.localToWorldMatrix.MultiplyPoint( randomPosition );
normalAtRandomPosition = this.transform.localToWorldMatrix.MultiplyVector( normalAtRandomPosition );
_particleSystem.Emit(
randomPosition,
normalAtRandomPosition * _particleSystem.startSpeed,
_particleSystem.startSize,
_particleSystem.startLifetime,
_particleSystem.startColor
);
}
}
}

Related

Problem rotating an object on its local orientation

Hello i am new in the forum! I hope i am in the right section! Im trying to rotate a camera (that rapresent the player POV) using the mouse delta and im rotating the camera in local coordinates not world coordinates and i want avoid gimbal lock effect. I read somewhere on the internet that for that purpose i have to use quaternions, and i read how to do that. The problem is that axis rotations works well moving in local orientation but one of the axis is losing its local orientation and it rotate following the world coordinates orientation. I will post the code and i hope someone can help me and telling me where im doing things wrong. Thanks!
public class Player : MonoBehaviour {
[Header("Camera")]
[SerializeField] private Camera _camera;
[SerializeField] private Vector2 _xMinMaxRotation = new Vector2(-90, 90);
[SerializeField] private Vector2 _yMinMaxRotation = new Vector2(-90, 90);
[SerializeField] private float _mouseXSensistivity = 1;
[SerializeField] private float _mouseYSensistivity = 1;
[SerializeField] private float _mouseZSensistivity = 1;
[SerializeField] private float _xStartRotation = 0;
[SerializeField] private float _yStartRotation = 0;
private Vector2 _mouseDelta;
private float _rotY, _rotX, _rotZ;
//public GameObject head;
// Start is called before the first frame update
void Start() {
Cursor.lockState = CursorLockMode.Locked;
}
// Update is called once per frame
void Update() {
_mouseDelta = new Vector2(Input.GetAxis("Mouse X"), Input.GetAxis("Mouse Y"));
MoveCamera();
}
private void MoveCamera() {
_rotX += _mouseDelta.x * _mouseXSensistivity * Time.deltaTime * 100;
_rotX = Mathf.Clamp(_rotX, _xMinMaxRotation.x, _xMinMaxRotation.y);
_rotY += _mouseDelta.y * _mouseYSensistivity * Time.deltaTime * 100;
_rotY = Mathf.Clamp(_rotY, _yMinMaxRotation.x, _yMinMaxRotation.y);
//Calculation for RotZ
if (Input.GetKey(KeyCode.Q)) {
_rotZ += +_mouseZSensistivity * Time.deltaTime * 50;
if (_rotZ > 25) _rotZ = 25;
}
else {
if (_rotZ > 0) {
_rotZ -= 2 * _mouseZSensistivity * Time.deltaTime * 50;
if (_rotZ < 0) _rotZ = 0;
}
}
if (Input.GetKey(KeyCode.E)) {
_rotZ += -_mouseZSensistivity * Time.deltaTime * 50;
if (_rotZ < -25) _rotZ = -25;
}
else {
if (_rotZ < 0) {
_rotZ -= 2 * -_mouseZSensistivity * Time.deltaTime * 50;
if (_rotZ > 0) _rotZ = 0;
}
}
Quaternion currentRotation = Quaternion.identity;
currentRotation = currentRotation * Quaternion.AngleAxis(_rotX, transform.up);
currentRotation = currentRotation * Quaternion.AngleAxis(-_rotY, transform.right);
currentRotation = currentRotation * Quaternion.AngleAxis(_rotZ, transform.forward);
_camera.transform.localRotation = currentRotation;
//head.transform.position = _camera.transform.position;
//head.transform.rotation = _camera.transform.rotation;
}
The last part with quaternions is where im trying to calculate angles in order to properly rotate in local coordinates.
You don’t need to use quaternions at all.
You can use transform.EulerAngles instead of the transform.rotation or transform.localEulerAngles instead of transform.LocalRotation.
I messed up the capitalization I’m sure.
Say you wanted to rotate the camera 10 degrees along the local x axis. That would look something like
transform.localEulerAngles = transform.localEulerAngles.Add(10,0,0);
That’s it as far as I know. If you wanna read more about this,
transfrom.localEulerAngles
If your question was completely different, let me know and I can change or remove my answer.

How to draw a line over a specific duration using Vectrosity [duplicate]

I created a diagonal line renderer by attaching the following script to an empty game object. How can I extend the line at both ends for a half its length and how can I also extend the line by say 1 unit along the x-axis? Both over a certain period of time.
public class DiagonalLine : MonoBehaviour {
bool firstLineComplete = false;
LineRenderer diagLine;
public Vector3 startPoint = new Vector3 (0, 0, 0);
public Vector3 endPoint = new Vector3 (1.0f, 1.0f, 0);
public float lineDrawSpeed;
// Use this for initialization
void Start () {
diagLine = gameObject.AddComponent<LineRenderer>();
diagLine.material = new Material (Shader.Find ("Sprites/Default"));
diagLine.startColor = diagLine.endColor = Color.green;
diagLine.startWidth = diagLine.endWidth = 0.15f;
diagLine.SetPosition (0, startPoint);
diagLine.SetPosition (1, endPoint);
}
}
This is basic vector math.
You have the line with (from end to start):
Vector3 v = start - end;
and then you extend on each side by half if it:
extensionA = start + (v * 0.5f);
extensionB = end + (v * -0.5f);
If you need to extend by 1 then normalize:
Vector3 v = (start - end).normalized;
extensionA = start + v;
extensionB = end + (v * -1f);
Break your problem into pieces:
1.Extend line by x units on both sides:
This is done with the Ray class. Create a new Ray instance from the startPoint and endPoint variables then use the Ray.GetPoint function to extend the line. You have to do this on both sides to get the new extended lines.
A simple wrapper for the Ray class to simplify this:
Vector3 extendLine(Vector3 startPoint, Vector3 endPoint, ExtendDirection extendDirection, float extendDistance)
{
Ray ray = new Ray();
//Start
if (extendDirection == ExtendDirection.START_POINT)
{
ray.origin = startPoint;
ray.direction = startPoint - endPoint;
}
//End
else if (extendDirection == ExtendDirection.END_POINT)
{
ray.origin = endPoint;
ray.direction = endPoint - startPoint;
}
//Extend
Vector3 newUnityPoint = ray.GetPoint(extendDistance);
//Debug.DrawLine(ray.origin, newUnityPoint, Color.blue);
return newUnityPoint;
}
public enum ExtendDirection
{
START_POINT, END_POINT
}
Extend to the Left end
Vector3 newStartPos = extendLine(startPoint, endPoint, ExtendDirection.START_POINT, 4);
diagLine.SetPosition(0, newStartPos);
Extend to the Right end
Vector3 newEndPos = extendLine(startPoint, endPoint, ExtendDirection.END_POINT, 4);
diagLine.SetPosition(1, newEndPos);
2.For animating/moving it over time, use coroutine and Time.deltaTime. Increment a variable with Time.deltaTime every frame to then use Vector3.Lerp to lerp the from and to value.
See this function for example.
With both combined, below is a complete function to extend both lines over time:
bool isRunning = false;
IEnumerator extentLineOverTime(LineRenderer targetLineRenderer, float extendDistance, float duration)
{
//Calculate Left from extension length
Vector3 fromValLeftPos = targetLineRenderer.GetPosition(0);
//Calculate Right from extension length
Vector3 fromValRightPos = targetLineRenderer.GetPosition(1);
//Calculate Left to extension length
Vector3 newLeftPos = extendLine(fromValLeftPos, fromValRightPos, ExtendDirection.START_POINT, extendDistance);
//Calculate Right to extension length
Vector3 newRightPos = extendLine(fromValLeftPos, fromValRightPos, ExtendDirection.END_POINT, extendDistance);
//Make sure there is only one instance of this function running
if (isRunning)
{
yield break; ///exit if this is still running
}
isRunning = true;
float counter = 0;
while (counter < duration)
{
counter += Time.deltaTime;
//Move to left overtime
Vector3 tempLeftPos = Vector3.Lerp(fromValLeftPos, newLeftPos, counter / duration);
targetLineRenderer.SetPosition(0, tempLeftPos);
//Move to Right overtime
Vector3 tempRightPos = Vector3.Lerp(fromValRightPos, newRightPos, counter / duration);
targetLineRenderer.SetPosition(1, tempRightPos);
yield return null;
}
isRunning = false;
}
USAGE:
LineRenderer diagLine;
public Vector3 startPoint = new Vector3(0, 0, 0);
public Vector3 endPoint = new Vector3(1.0f, 1.0f, 0);
// Use this for initialization
void Start()
{
diagLine = gameObject.AddComponent<LineRenderer>();
diagLine.material = new Material(Shader.Find("Sprites/Default"));
diagLine.startColor = diagLine.endColor = Color.green;
diagLine.startWidth = diagLine.endWidth = 0.15f;
diagLine.SetPosition(0, startPoint);
diagLine.SetPosition(1, endPoint);
//Extend Line Over time
StartCoroutine(extentLineOverTime(diagLine, 4, 3));
}
The StartCoroutine(extentLineOverTime(diagLine, 4, 3)); will extend the line 4 units away from both sides within 3 seconds.

HoloLens Draw a graph

What is the best way to draw a graph for the HoloLens in unity?
I am new to this platform and have no idea which packages will work and which dont, the graph gets data dynamically.
EDIT: I have tried LineRenderer but it seems very limited in version 5.4 of Unity
A possible Solution for drawing a 3D-Graph is using a particle system:
Simple Example for a Component Script for a particle system:
public class Graph: MonoBehaviour {
//Particle-Resolution of the Graph
[Range(10, 100)]
public int resolution = 10;
private int currentResolution;
private ParticleSystem.Particle[] points;
void Start()
{
currentResolution = resolution;
points = new ParticleSystem.Particle[resolution];
float increment = 1f / (resolution - 1);
for (int i = 0; i < resolution; i++)
{
float x = i * increment;
points[i].position = new Vector3(x, 0f, 0f);
points[i].startColor = new Color(0f, 0f, 0f);
points[i].startSize = 0.1f;
}
}
void Update()
{
if ((currentResolution != resolution) || (points == null))
{
CreatePoints();
}
FunctionDelegate f = functionDelegates[(int)function];
for (int i = 0; i < points.Length; i++)
{
Vector3 p = points[i].position;
p.y = Sine(p.x);
points[i].position = p;
Color c = points[i].GetCurrentColor(GetComponent<ParticleSystem>());
c.g = p.y;
c.r = 1f - p.y;
points[i].startColor = c;
}
GetComponent<ParticleSystem>().SetParticles(points, points.Length);
}
private static float Sine(float x)
{
return 0.5f + 0.5f * Mathf.Sin(2 * Mathf.PI * x + Time.timeSinceLevelLoad);
}
}
A good tutorial for drawing 2D/3D graphs (including this example) with a particle system from CatLikeCoding (Jasper Flick). Refer to: http://catlikecoding.com/unity/tutorials/graphs/. It's a bit outdated and you must use startSize/startColor instead the depreceated color/size-Properties in this case.
But i'have testet it with the hololens allready and it worked fine. Some experiments with the HoloToolkit shaders for a better performance are necessary if you have a big amount of particles :-)
If you have further questions: Just ask me.

Single object 3D viewer for Google Cardboard with Unity 5

I'm trying to recreate the functionality of the Google Cardboard app’s 'Exhibit' demo. i.e. viewing a single object from all sides - look up and you see under the object, look down and you view it from above, look left or right and you see it from the side, then back.
I've tried a number of things like making the object a child of the camera, and using transform.LookAt(target); to keep the camera focused on the object but it isn't working.
New to Unity5 so any help would be very much appreciated.
UPDATE
Using code from a SmoothMouseLook script (http://pastebin.com/vMFkZJAm) this is the closest I've got so far, but it doesn't really work and feels too 'out of control' (the object keeps spinning rather than smoothly turning for inspection) and much less predictable than the 'Exhibit' demo. My guess is that I'm over complicating things. Anyone have any ideas?...
On the Camera(s) ("Main Camera") attach this to keep focused on the object:
using UnityEngine;
using System.Collections;
public class LookAt : MonoBehaviour {
public Transform target;
void Update () {
transform.LookAt(target);
}
}
On the Object, attach this script:
using UnityEngine;
using System.Collections;
using System.Collections.Generic;
public class SmoothMouseLook : MonoBehaviour
{
/*
This script is used to average the mouse input over x
amount of frames in order to create a smooth mouselook.
*/
//Mouse look sensitivity
public float sensitivityX = 1f;
public float sensitivityY = 1f;
//Default mouse sensitivity
public float defaultSensX = 1f;
public float defaultSensY = 1f;
//Minimum angle you can look up
public float minimumY = -60f;
public float maximumY = 60f;
//Minimum angle you can look up
public float minimumX = -60f;
public float maximumX = 60f;
//Number of frames to be averaged, used for smoothing mouselook
public int frameCounterX = 35;
public int frameCounterY = 35;
//Mouse rotation input
private float rotationX = 0f;
private float rotationY = 0f;
//Used to calculate the rotation of this object
private Quaternion xQuaternion;
private Quaternion yQuaternion;
private Quaternion originalRotation;
//Array of rotations to be averaged
private List<float> rotArrayX = new List<float> ();
private List<float> rotArrayY = new List<float> ();
void Start ()
{
//Lock/Hide cursor
if (GetComponent<Rigidbody>())
GetComponent<Rigidbody>().freezeRotation = true;
originalRotation = transform.localRotation;
}
void FixedUpdate ()
{
//Mouse/Camera Movement Smoothing:
//Average rotationX for smooth mouselook
float rotAverageX = 0f;
//rotationX += Camera.main.transform.eulerAngles.x * sensitivityX;
//rotationX += Cardboard.SDK.HeadRotation.eulerAngles.x * sensitivityX;
rotationX += Cardboard.SDK.HeadPose.Orientation.x * sensitivityX;
rotationX = ClampAngle (rotationX, minimumX, maximumX);
//Add the current rotation to the array, at the last position
rotArrayX.Add (rotationX);
//Reached max number of steps? Remove the oldest rotation from the array
if (rotArrayX.Count >= frameCounterX) {
rotArrayX.RemoveAt (0);
}
//Add all of these rotations together
for (int i_counterX = 0; i_counterX < rotArrayX.Count; i_counterX++) {
//Loop through the array
rotAverageX += rotArrayX[i_counterX];
}
//Now divide by the number of rotations by the number of elements to get the average
rotAverageX /= rotArrayX.Count;
//Average rotationY, same process as above
float rotAverageY = 0;
//rotationY += Camera.main.transform.eulerAngles.y * sensitivityY;
//rotationY += Cardboard.SDK.HeadRotation.eulerAngles.y * sensitivityY;
rotationY += Cardboard.SDK.HeadPose.Orientation.y * sensitivityY;
rotationY = ClampAngle (rotationY, minimumY, maximumY);
rotArrayY.Add (rotationY);
if (rotArrayY.Count >= frameCounterY) {
rotArrayY.RemoveAt (0);
}
for (int i_counterY = 0; i_counterY < rotArrayY.Count; i_counterY++) {
rotAverageY += rotArrayY[i_counterY];
}
rotAverageY /= rotArrayY.Count;
//Apply and rotate this object
xQuaternion = Quaternion.AngleAxis (rotAverageX, Vector3.up);
yQuaternion = Quaternion.AngleAxis (rotAverageY, Vector3.left);
transform.localRotation = originalRotation * xQuaternion * yQuaternion;
}
private float ClampAngle (float angle, float min, float max)
{
if (angle < -360f)
angle += 360f;
if (angle > 360f)
angle -= 360f;
return Mathf.Clamp (angle, min, max);
}
}
For that particular use case, you don't need a script. Assuming you are using the CardboardMain prefab, do this:
Put the object at the origin, and the CardboardMain there too.
In the Cardboard settings, set Neck Model Scale to 0.
Open up CardboardMain and select Main Camera under the Head object.
Set it's Transform Position Z value to a negative value (far enough to see the object).
(You can think of this as the "selfie-stick" camera model.)

2D projectile trajectory prediction (unity3d)

(Using unity3d 4.3 2d, it uses box2d like physics).
I have problems with predicting trajectory
I'm using:
Vector2 startPos;
float power = 10.0f;
float interval = 1/30.0f;
GameObject[] ind;
void Start (){
transform.rigidbody2D.isKinematic = true;
ind = new GameObject[dots];
for(int i = 0; i<dots; i++){
GameObject dot = (GameObject)Instantiate(Dot);
dot.renderer.enabled = false;
ind[i] = dot;
}
}
void Update (){
if(shot) return;
if(Input.GetAxis("Fire1") == 1){
if(!aiming){
aiming = true;
startPos = Input.mousePosition;
ShowPath();
}
else{
CalculatePath();
}
}
else if(aiming && !shot){
transform.rigidbody2D.isKinematic = false;
transform.rigidbody2D.AddForce(GetForce(Input.mous ePosition));
shot = true;
aiming = false;
HidePath();
}
}
Vector2 GetForce(Vector3 mouse){
return (new Vector2(startPos.x, startPos.y)- new Vector2(mouse.x, mouse.y))*power;
}
void CalculatePath(){
ind[0].transform.position = transform.position; //set frist dot to ball position
Vector2 vel = GetForce(Input.mousePosition); //get velocity
for(int i = 1; i < dots; i++){
ind[i].renderer.enabled = true; //make them visible
Vector3 point = PathPoint(transform.position, vel, i); //get position of the dot
point.z = -1.0f;
ind[i].transform.position = point;
}
}
Vector2 PathPoint(Vector2 startP, Vector2 startVel, int n){
//Standard formula for trajectory prediction
float t = interval;
Vector2 stepVelocity = t*startVel;
Vector2 StepGravity = t*t*Physics.gravity;
Vector2 whattoreturn = ((startP + (n * stepVelocity)+(n*n+n)*StepGravity) * 0.5f);
return whattoreturn;
}
Using this, I get wrong trajectory.
1. It's like gravity doesn't drag trajectory down at all, and yes i know that gravity is weak because:
t*t*Physics.gravity = 0.03^2 * vector2(0, -9.8) = vector2(0, -0.00882)
But that is the formula :S
2. Since gravity is low, velocity is too strong.
Here is the video:
http://tinypic.com/player.php?v=1z50w3m&s=5
Trajectory formula form:
http://www.iforce2d.net/b2dtut/projected-trajectory
What should I do?
I found that if I set
StepGravity to something stronger like (0, -0.1)
and devide startVel by 8
I get nearly right trajectory, but i don't want that, I need true trajectory path.
Users from answer.unity3d.com said I should ask here, because here is a bigger group of mathematical coders.
And I searched a lot about this problem (that how I found that formula).
you're only calculating the effect of gravity over 1/30th of a second for each step - you need to do it cumulatively. Step 1 should end with a velocity of 0.09G, Step 2 with .18G, step3 with .27G etc.
Here's a very simple example that draws the ballistic trajectory based on start velocity and a supplied time:
using UnityEngine;
using System.Collections;
public class grav : MonoBehaviour {
public Vector3 StartVelocity;
public float PredictionTime;
private Vector3 G;
void OnDrawGizmos()
{
if (G == Vector3.zero)
{
// a hacky way of making sure this gets initialized in editor too...
// this assumes 60 samples / sec
G = new Vector3(0,-9.8f,0) / 360f;
}
Vector3 momentum = StartVelocity;
Vector3 pos = gameObject.transform.position;
Vector3 last = gameObject.transform.position;
for (int i = 0; i < (int) (PredictionTime * 60); i++)
{
momentum += G;
pos += momentum;
Gizmos.DrawLine(last, pos);
last = pos;
}
}
}
In you version you'd want draw your dots where I'm drawing the Gizmo, but it's the same idea unless I'm misunderstanding your problem.