I'm using Random.onUnitSphere to simulate bubbles floating around jostling for position. It works well although the movement is too "jerky". I'd like to create the same effect but slow it down and make smoother random movements. Is there anyway I can easily achieve this? Here's my code:
private void Update()
{
if (floaty == true)
{
rb.AddRelativeForce(Random.onUnitSphere * speed);
speed = 0.06f;
}
}
A Perlin noise random walker should work
//There are probably better ways to do this.
Vector3 RandomSmoothPointOnUnitSphere(float time)
{
//Get the x of the vector
float x = Math.PerlinNoise(time, /* your x seed */);
//Get the y of the vector
float y = Math.PerlinNoise(time, /* your y seed */);
//Get the z of the vector
float z = Math.PerlinNoise(time, /* your z seed */);
//Create a vector3
Vector3 vector = new Vector3(x, y, z);
//Normalize the vector and return it
return Vector3.Normalize(vector);
}
And in the Update function
if (floaty)
{
//Get the vector
Vector3 movementvector = RandomSmoothPointOnUnitSphere(Time.time);
//You can also use CharacterController.Move()
transform.Translate(movementvector * Time.deltatime);
}
I should also mention that this approach shouldn't work with RigidBody.ApplyForce(), but I don't usually use Unity's default physics, so it may. Regardless, it shouldn't change anything.
Related
I am trying to have a gameobject in unity react with sound if another object is inside it. I want the gameobject to use the entering objects location to then see what voxel is closest and then play audio based on the voxel intensity/colour. Does anyone have any ideas? I am working with a dataset that is 512x256x512 voxels. I want it to work if the object is resized as well. Any help is much appreciated :).
The dataset I'm working with is a 3d .mhd medical scan of a body. Here is how the texture is added to the renderer on start:
for (int k = 0; k < NumberOfFrames; k++) {
string fname_ = "T" + k.ToString("D2");
Color[] colors = LoadData(Path.Combine (imageDir, fname_+".raw"));
_volumeBuffer.Add (new Texture3D (dim [0], dim [1], dim [2], TextureFormat.RGBAHalf, mipmap));
_volumeBuffer[k].SetPixels(colors);
_volumeBuffer [k].Apply ();
}
GetComponent<Renderer>().material.SetTexture("_Data", _volumeBuffer[0]);
The size of the object is defined by using the mdh header files spacing as well as voxel dimensions:
transform.localScale = new Vector3(mhdheader.spacing[0] * volScale, mhdheader.spacing[1] * volScale * dim[1] / dim[0], mhdheader.spacing[2] * volScale * dim[2] / dim[0]);
I have tried making my own function to get the index from the world by offsetting it to the beginning of the render mesh (not sure if this is right). Then, scaling it by the local scale. Then, multiplying by the amount of voxels in each dimension. However, I am not sure if my logic is right whatsoever... Here is the code I tried:
public Vector3Int GetIndexFromWorld(Vector3 worldPos)
{
Vector3 startOfTex = gameObject.GetComponent<Renderer>().bounds.min;
Vector3 localPos = transform.InverseTransformPoint(worldPos);
Vector3 localScale = gameObject.transform.localScale;
Vector3 OffsetPos = localPos - startOfTex;
Vector3 VoxelPosFloat = new Vector3(OffsetPos[0] / localScale[0], OffsetPos[1] / localScale[1], OffsetPos[2] / localScale[2]);
VoxelPosFloat = Vector3.Scale(VoxelPosFloat, new Vector3(voxelDims[0], voxelDims[1], voxelDims[2]));
Vector3Int voxelPos = Vector3Int.FloorToInt(VoxelPosFloat);
return voxelPos;
}
You can try setting up a large amount of box colliders and the OnTriggerEnter() function running on each. But a much better solution is to sort your array of voxels and then use simple math to clamp the moving objects position vector to ints and do some maths to map the vector to an index in the array. For example the vector (0,0,0) could map to voxels[0]. Then just fetch that voxels properties as you like. For a voxel application this would be a much needed faster calculation than colliders.
I figured it out I think. If anyone sees any flaw in my coding, please let me know :).
public Vector3Int GetIndexFromWorld(Vector3 worldPos)
{
Vector3 deltaBounds = rend.bounds.max - rend.bounds.min;
Vector3 OffsetPos = worldPos - rend.bounds.min;
Vector3 normPos = new Vector3(OffsetPos[0] / deltaBounds[0], OffsetPos[1] / deltaBounds[1], OffsetPos[2] / deltaBounds[2]);
Vector3 voxelPositions = new Vector3(normPos[0] * voxelDims[0], normPos[1] * voxelDims[1], normPos[2] * voxelDims[2]);
Vector3Int voxelPos = Vector3Int.FloorToInt(voxelPositions);
return voxelPos;
}
Good day,
I'd like to program a constantly moving ball (object3) being passed between two stationary objects (object1, object2), with the ability to set the max height Y of the pass trajectory dynamically.
What would you argue is the best way to program the ball physics for this concept?
I've looked at using addForce on a default sphere w/ a rigidbody. It seems like there should be an equation that expresses the trajectory of a pass of object3 from object1's x to object2's x... at a known, given speed, with a known, set mass, and a known gravity environment.
However, currently I have a Vector3.Lerp interpolating the ball between the two objects on each FixedUpdate() with t expressed as:
`(Mathf.Sin(speed * Time.time) + 1.0f) / 2.0f;`
It works and all, but with this approach, it seems there's no clear way to add height to the trajectory of the ball path. I've considered adding the height to the Y value in object2 until the ball is half way there, and then setting it back to the original Y position... but it just feels wrong! Thoughts?
Thanks!
Okey so if I understand you correctly currently you are doing
privte void FixedUpdate()
{
var factor = (Mathf.Sin(speed * Time.time) + 1.0f) / 2.0f;
object1.MovePosition(Vector3.Lerp(object2.position, object3.position, factor));
}
which moves the ball pingpong between object1 and object2 position but only planar.
Assuming for now the objects will only be moving within the XZ plane and never have different Y position in order to rather get a curve with height you could treat the separatly:
- Interpolate between both positions as before
- Separately calculate the Y position with sinus or any other mathematical curve function - for realistic physics probably rather a parabola actually
Could look somhow like
public class Example : MonoBehaviour
{
public Rigidbody object1;
public Transform object2;
public Transform object3;
// adjust in the Inspector
public float speed = 1;
public float Amplitude = 0;
// Just for debug
[Range(0, 1)] [SerializeField] private float linearFactor;
[SerializeField] private float yPosition;
private void FixedUpdate()
{
// This always returns a value between 0 and 1
// and linearly pingpongs forth and back
linearFactor = Mathf.PingPong(Time.time * speed, 1);
// * Mathf.PI => gives now a value 0 - PI
// so sinus returns correctly 0 - 1 (no need for +1 and /2 anymore)
// then simply multiply by the desired amplitude
var sinus = Mathf.Sin(linearFactor * Mathf.PI);
yPosition = sinus * Amplitude;
// As before interpolate between the positions
// later we will ignore/replace the Y component
var position = Vector3.Lerp(object2.position, object3.position, linearFactor);
object1.MovePosition(new Vector3(position.x, yPosition, position.z));
}
}
You could optionally also try and add some dumping in the Y direction in order to make the vertical movement more realistic (slow down when reaching the peak). I tried a bit using inverted SmoothStep like
// just for debug
[Range(0, 1)] [SerializeField] private float dampedSinusFactor;
[Range(0, 1)] [SerializeField] private float linearFactor;
[SerializeField] private float yPosition;
private void FixedUpdate()
{
// Use two different factros:
// - a linear one for movement in XZ
// - a smoothed one for movement in Y (in order to slow down when reaching the peak ;) )
linearFactor = Mathf.PingPong(Time.time * speed, 1);
dampedSinusFactor = InvertSmoothStep(linearFactor);
// * Mathf.PI => gives now a value 0 - PI
// so sinus returns correctly 0 - 1 ()
// then simply multiply by the desired amplitude
var sinus = Mathf.Sin(dampedSinusFactor * Mathf.PI);
yPosition = sinus * Amplitude;
// later we will ignore/replace the Y component
var position = Vector3.Lerp(object2.position, object3.position, linearFactor);
object1.position = new Vector3(position.x, yPosition, position.z);
}
// source: https://stackoverflow.com/a/34576808/7111561
private float InvertSmoothStep(float x)
{
return x + (x - (x * x * (3.0f - 2.0f * x)));
}
However for slow movements this looks a bit strange yet. But you can come up with any other maths curve that results in the expected behavior for x=[0,1] ;)
I would like to simulate a vortex like force to a "bunch" of objects in my scene.
How can I do in Unity ?
Thanks
If you are using the physics system, there's two parts to this. Applying the vortex force, and getting the nice swirling effect. To apply the vortex force you can just loop over the rigidbodies and apply the force. To make the swirl look like a proper vortex swirl, you need to start the objects off with a tangential velocity that you can figure out using the vector cross product.
public float VortexStrength = 1000f;
public float SwirlStrength = 5f;
void Start () {
foreach(GameObject g in RigidBodies){
//to get them nice and swirly, use the perpendicular to the direction to the vortex
Vector3 direction = Vortex.transform.position - g.transform.position;
var tangent = Vector3.Cross(direction, Vector3.up).normalized * SwirlStrength;
g.GetComponent<Rigidbody>().velocity = tangent;
}
}
void Update(){
//apply the vortex force
foreach(GameObject g in RigidBodies){
//force them toward the center
Vector3 direction = Vortex.transform.position - g.transform.position;
g.GetComponent<Rigidbody>().AddForce(direction.normalized * Time.deltaTime * VortexStrength);
}
}
Circular motion:
float angle =0;
float speed=(2*Mathf.PI)/5 //2*PI in degress is 360, so you get 5 seconds to complete a circle
float radius=5;
void Update()
{
angle += speed*Time.deltaTime; //if you want to switch direction, use -= instead of +=
x = Mathf.Cos(angle)*radius;
y = Mathf.Sin(angle)*radius;
}
where the center of your circle is the center of your vortex.
Of course:
If you want multiple objects with diferent distance from vortex's
center you have to play with your radius variable (i would add a
Random.Range(minDistance, maxDistance))
If you want diferent speeds you can randomize/change the speed.
Randomize/change your x/y if you don't want a perfect circle
Hope i was clear enought.
I a new here and i try to start working with Unity Engine.
Could somebody explain me, how works Quaternion.Slerp? Because I want to rotate some object in different angles 90, 180 and 270. My code you can see below. Unfortunately when I add 180 degrees, object make crazy things and than put rotation to (0, 180, 180) for this game object. I would like to get (180,0,0)
public float speed = 0.1F;
private float rotation_x;
void Update()
{
if (Input.GetButtonDown("Fire1"))
{
rotation_x = transform.rotation.eulerAngles.x;
rotation_x += 180;
}
transform.rotation = Quaternion.Slerp(transform.rotation, Quaternion.Euler(rotation_x, transform.eulerAngles.y, transform.eulerAngles.z), Time.time * speed);
}
Most examples out there including Unity examples from their official website are using Lerp in the wrong way. They didn't even bother to describe how it works in the API documentation. They just starch it in the Update() function and call it a day.
Mathf.Lerp, Vector3.Lerp, and Quaternion.Slerp work by changing from one position/rotation to another with the t value(last parameter) being passed in.That t value is also know as time.
The min of the t value is 0f and the max is 1f.
I will explain this with Mathf.Lerp to make it easier to understand. The Lerp functions are all the-same for both Mathf.Lerp, Vector and Quaternion.
Remember that Lerp takes two values and returns values between them. If we have a value of 1 and 10 and we do Lerp on them:
float x = Mathf.Lerp(1f, 10f, 0f); will return 1.
float x = Mathf.Lerp(1f, 10f, 0.5f); will return 5.5
float x = Mathf.Lerp(1f, 10f, 1f); will return 10
As you can see, the t(0) returns the min of the number passed in, t(1) returns the max value passed in and t(0.5) will return mid point between the min and the max value. You are doing it wrong when you pass any t value that is < 0 or > 1. That code in you Update() function is doing just that. Time.time will increase every second and will be > 1 in a second, so you have problems with that.
It recommended to use Lerp in another function/Coroutine instead of the Updated function.
Note:
Using Lerp has a bad side of it when it comes to rotation. Lerp does not know how to rotate Object with the shortest path. So bear that in mind. For example, you have an Object with 0,0,90 position. Lets say you want to move the rotation from that to 0,0,120 Lerp can sometimes rotate left instead of right to reach that new position which means it take longer to reach that distance.
Let's say we want to make the rotation (0,0,90) from whatever the current rotation is. The code below will change the rotation to 0,0,90 in 3 seconds.
ROTATION OVER TIME:
void Start()
{
Quaternion rotation2 = Quaternion.Euler(new Vector3(0, 0, 90));
StartCoroutine(rotateObject(objectToRotate, rotation2, 3f));
}
bool rotating = false;
public GameObject objectToRotate;
IEnumerator rotateObject(GameObject gameObjectToMove, Quaternion newRot, float duration)
{
if (rotating)
{
yield break;
}
rotating = true;
Quaternion currentRot = gameObjectToMove.transform.rotation;
float counter = 0;
while (counter < duration)
{
counter += Time.deltaTime;
gameObjectToMove.transform.rotation = Quaternion.Lerp(currentRot, newRot, counter / duration);
yield return null;
}
rotating = false;
}
INCREMENTAL ANGULAR ROTATION OVER TIME:
And to just rotate the Object to 90 in z axis, the code below is a great example of that. Please understand there is a difference between moving Object to new rotational point and just rotating it.
void Start()
{
StartCoroutine(rotateObject(objectToRotate, new Vector3(0, 0, 90), 3f));
}
bool rotating = false;
public GameObject objectToRotate;
IEnumerator rotateObject(GameObject gameObjectToMove, Vector3 eulerAngles, float duration)
{
if (rotating)
{
yield break;
}
rotating = true;
Vector3 newRot = gameObjectToMove.transform.eulerAngles + eulerAngles;
Vector3 currentRot = gameObjectToMove.transform.eulerAngles;
float counter = 0;
while (counter < duration)
{
counter += Time.deltaTime;
gameObjectToMove.transform.eulerAngles = Vector3.Lerp(currentRot, newRot, counter / duration);
yield return null;
}
rotating = false;
}
All my examples are based on frame-rate of the device. You can use real-time by replacing Time.deltaTime with Time.delta but more calculation is required.
Before anything, you can't add 180 on euler angles like that, and that's mainly what is causing your problem. You'd better use quaternion directly instead, or work on the transform itself.
You can think of a quaternion as an orientation in space. In contrary to what have been said, I do recommend learning how to use them if you can. However, I don't recommend using euler angles at all... as they're suject to different writing conventions, and will fail sometimes. You can look at 'gimbal lock' if you want details about that.
Simply a slerp or lerp (standing for spherical linear interpolation, or linear interpolation respectively) is a way to interpolate (go from one orientation to another, by increasing t from 0 to 1, in a coroutine or anywhere else) between orientation A and B. The difference between the two is that the slerp is giving you the shortest path from A to B.
In the end, when t = 1, lerp(A,B,t) and slerp(A,B,t) will give you B.
In your case, if you want to instantly rotate an object in space to a specific orientation, I suggest you use Quaternion.AngleAxis which is the most forward way to describe mathematically a quaternion.
If you want to add a rotation, say 90° to you actual orientation (without animation between the two), you can do something like this :
transform.rotation *= Quaternion.AngleAxis(axis_of_rotation, angle)
or use transform.rotate (depending on the parameters, it can be a right multiply, or left : local, or world transform).
Programmers' answer is detailling how to animate your transform. But I do suggest you to investigate quaternion themselves, as it will give you global understanding of space transforms.
I am fairly new to Unity so please bear with me I have tried looking for the answer everywhere, but have had no luck.
Basically I am using onMouseDrag to move a sprite around the background for a classroom (1366x768) that has a table. However, I want to limit where the sprite can go so that it does not end up off screen or off of the table on my background.
My sprite has the 2d box collider and rigidbody components attached (gravity is set to zero and it is at a fixed angle). I thought that by placing four 2d box colliders around the area I want to keep the sprite in it would be enough to contain it but the sprite simply goes straight through them.
I also read up about using Mathf.Clamp to restrict the area but I do not really understand how to use it from the examples I have seen.
Below is my code for moving the sprite:
using UnityEngine;
using System.Collections;
public class MovementScript : MonoBehaviour {
float x;
float y;
void Update() {
x = Input.mousePosition.x;
y = Input.mousePosition.y;
}
public void OnMouseDrag() {
transform.position = Camera.main.ScreenToWorldPoint (new Vector3 (x, y, 1.0f));
}
}
Any help would be greatly appreciated!
Moving an object using its transform is not the same as moving it.
When you use the transform, the object doesn't "move", it teleports every Update by a small amount. Unfortunately, the Rigidbody can't detect this change in position as movement and thus does not react with any colliders. Regardless, that's probably the more complicated way to do this. Using Clamp is definitely easier.
Clamp is a pretty straightforward function. it takes three args: a value, a min, and a max. If the value is less than min or greater than max, it returns that boundary. Otherwise, it returns the value itself.
For instance,
Mathf.Clamp(5, 1, 3); //returns 3
Mathf.Clamp(2, 1, 3); //returns 2
Mathf.Clamp(-2, 1, 3); //returns 1
This is simply a convenience function for something like this:
if(val > max) {
return max;
} else if(val < min) {
return min;
} else {
return val;
}
So using Clamp, you can restrict the values of your x and y coordinates:
//to avoid confusion, I'm referring to your x and y variables
//as inputX and inputY. they represent the mouse position.
public void OnMouseDrag() {
Vector3 pos = Vector3.zero;
pos.x = Mathf.Clamp(inputX, minX, maxX);
pos.y = Mathf.Clamp(inputY, minY, maxY);
pos.z = 1.0;
transform.position = Camera.main.ScreenToWorldPoint (pos);
}
Mathf.Clamp will keep the X and Y coordinates of your Transform within the range (minX, maxX) and (minY, maxY) respectively. You can create these variables as inspector variables so you can change them on the fly.