Develop Reference

Unity3d lineRenderer is invisible on some parts

I have 3 Spheres and a lineRenderer which is connected to the spheres. I'm using Bezier curves to get a smooth curves between the spheres.
The code is looking like this:
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class LineController : MonoBehaviour
{
private LineRenderer lineRenderer;
public Transform p0;
public Transform p1;
public Transform p2;
void Start()
{
lineRenderer = GetComponent<LineRenderer>();
lineRenderer.sortingOrder = 1;
}
void Update()
{
DrawQuadraticBezierCurve(p0.position, p1.position, p2.position);
}
void DrawQuadraticBezierCurve(Vector3 point0, Vector3 point1, Vector3 point2)
{
lineRenderer.positionCount = 100;
float t = 0f;
Vector3 B = new Vector3(0, 0, 0);
for (int i = 0; i < lineRenderer.positionCount; i++)
{
B = (1 - t) * (1 - t) * point0 + 2 * (1 - t) * t * point1 + t * t * point2;
lineRenderer.SetPosition(i, B);
t += (1 / (float)lineRenderer.positionCount);
}
}
}
The Problem is, that the is invisible on some parts when I move the spheres.
I don't know why this is happening. I'm using Mixed Reality Toolkit. In the best case the line should be displayed as an 3D object like a long cube.
Maybe anybody is familiar with this kind of "error"?

Strange outputs for a moving platform in Unity

First off, sorry it this isn't written very well, I've spend hours debugging this and I'm very stressed. I'm trying to make a moving platform in unity that can move between way-points, I don't want to have to have tons of gameobjects in the world taking up valuable processing power though so I'm trying to use something I can just add to the script through the editor.
The only problem is that it seems to be doing this at an incredible speed:
Black = The Camera View, Blue = The platform and where it should be going based on waypoints, Red = What it is currently doing.
I've spend hours trying to find a fix but I have no idea why it's doing this.
My Script on the Platform:
public Vector3[] localWaypoints;
Vector3[] globalWaypoints;
public float speed;
public bool cyclic;
public float waitTime;
[Range(0, 2)]
public float easeAmount;
int fromWaypointIndex;
float percentBetweenWaypoints;
float nextMoveTime;
void Start()
{
globalWaypoints = new Vector3[localWaypoints.Length];
for (int i = 0; i < localWaypoints.Length; i++)
{
globalWaypoints[i] = localWaypoints[i] + transform.position;
}
}
void Update()
{
Vector3 velocity = CalculatePlatformMovement();
transform.Translate(velocity);
}
float Ease(float x)
{
float a = easeAmount + 1;
return Mathf.Pow(x, a) / (Mathf.Pow(x, a) + Mathf.Pow(1 - x, a));
}
Vector3 CalculatePlatformMovement()
{
if (Time.time < nextMoveTime)
{
return Vector3.zero;
}
fromWaypointIndex %= globalWaypoints.Length;
int toWaypointIndex = (fromWaypointIndex + 1) % globalWaypoints.Length;
float distanceBetweenWaypoints = Vector3.Distance(globalWaypoints[fromWaypointIndex], globalWaypoints[toWaypointIndex]);
percentBetweenWaypoints += Time.deltaTime * speed / distanceBetweenWaypoints;
percentBetweenWaypoints = Mathf.Clamp01(percentBetweenWaypoints);
float easedPercentBetweenWaypoints = Ease(percentBetweenWaypoints);
Vector3 newPos = Vector3.Lerp(globalWaypoints[fromWaypointIndex], globalWaypoints[toWaypointIndex], easedPercentBetweenWaypoints);
if (percentBetweenWaypoints >= 1)
{
percentBetweenWaypoints = 0;
fromWaypointIndex++;
if (!cyclic)
{
if (fromWaypointIndex >= globalWaypoints.Length - 1)
{
fromWaypointIndex = 0;
System.Array.Reverse(globalWaypoints);
}
}
nextMoveTime = Time.time + waitTime;
}
return newPos - transform.position;
}
struct PassengerMovement
{
public Transform transform;
public Vector3 velocity;
public bool standingOnPlatform;
public bool moveBeforePlatform;
public PassengerMovement(Transform _transform, Vector3 _velocity, bool _standingOnPlatform, bool _moveBeforePlatform)
{
transform = _transform;
velocity = _velocity;
standingOnPlatform = _standingOnPlatform;
moveBeforePlatform = _moveBeforePlatform;
}
}
void OnDrawGizmos()
{
if (localWaypoints != null)
{
Gizmos.color = Color.red;
float size = .3f;
for (int i = 0; i < localWaypoints.Length; i++)
{
Vector3 globalWaypointPos = (Application.isPlaying) ? globalWaypoints[i] : localWaypoints[i] + transform.position;
Gizmos.DrawLine(globalWaypointPos - Vector3.up * size, globalWaypointPos + Vector3.up * size);
Gizmos.DrawLine(globalWaypointPos - Vector3.left * size, globalWaypointPos + Vector3.left * size);
}
}
}
UPDATE: Upon further testing I found that if the first object in my localWaypoint array is set to 0,0,0 and my 2nd object is set to 1,0,0 then the platform will spiral to the right, making sure to hit the waypoints as it's spiraling, and then spiraling out into nowhere like in the image above. But if I set my first object to 0,0,0 and my second object to -1,0,0 then the object will act the same way as before, but will spiral to the left as displayed in this image. (The second image has also bee updated to display how the platfrom makes sure to hit both waypoints before is spirals out into nowhere).
I've also noticed that if I set both waypoints to 0,0,0 then the platform stays still, these 2 things prove that it has somthing to do with the way the waypoints are being handled and not some other script or parent object interfering.

Using the updated numbers ([0,0,0], [1,0,0]) works in my test app. However, if I put a rotation on the object's Y axis, then I see behavior like you are seeing. In Update, if you change:
transform.Translate(velocity);
to
transform.Translate(velocity, Space.World);
You should see your desired behavior. Note that "transform.Translate(velocity)" is the same as "transform.Translate(velocity, Space.Self)". Your translation is being rotated.
If you are curious, take a look at this for more information on how the values in the transform are applied:
https://gamedev.stackexchange.com/questions/138358/what-is-the-transformation-order-when-using-the-transform-class

Check if two lines intersect

I need to check if two lines intersect. These are currently wrapped in edge colliders.
In my minimal example i using Collider2D.OverlapsCollider
public class EdgeColliderChecker : MonoBehaviour
{
public EdgeCollider2D e1;
public EdgeCollider2D e2;
void Update () {
Collider2D[] results1 = new Collider2D[1];
e1.OverlapCollider(new ContactFilter2D(), results1);
if (results1[0] != null)
{
Debug.Log(results1[0].name);
}
Collider2D[] results2 = new Collider2D[1];
e1.OverlapCollider(new ContactFilter2D(), results2);
if (results2[0] != null) {
Debug.Log(results2[0].name);
}
}
}
This is how i have set up my scene:
As you can see in the picture above the two lines clearly intersect.
The issue is that nothing is outputed to the console.
I am not 100% sure about how ContactFilter should be configured but looking at the documentation it is used for filtering out results. So leaving it blank should include everything.
I really only need to do the check between two lines. So a function that takes them as arguments and returns a bool indicating intersection would be most convenient. Unfortunetaly I could not find such function in Unity.
It should not be overly complicated to construct the function myself but i would prefer to use the functions unity provide as much as possible. So consider this more of a unity related question than a math related one.
EDIT:
Using Collider2D.IsTouching(Collider2D) does not seem to work either. I use the same setup as before with this code instead:
public class EdgeColliderChecker : MonoBehaviour
{
public EdgeCollider2D e1;
public EdgeCollider2D e2;
void Update () {
if (e1.IsTouching(e2)) {
Debug.Log("INTERSECTION");
}
}
}
Edit 2:
I tried creating my own method for this:
public static class EdgeColliderExtentions {
public static List<Collider2D> GetInterSections(this EdgeCollider2D collider)
{
List<Collider2D> intersections = new List<Collider2D>();
Vector2[] points = collider.points;
for (int i = 0; i < points.Length - 1; i++)
{
Vector2 curr = collider.transform.TransformPoint(points[i]);
Vector2 next = collider.transform.TransformPoint(points[i + 1]);
Vector2 diff = next - curr;
Vector2 dir = diff.normalized;
float distance = diff.magnitude;
RaycastHit2D[] results = new RaycastHit2D[30];
ContactFilter2D filter = new ContactFilter2D();
Debug.DrawLine(curr, curr + dir * distance, Color.red, 1 / 60f);
int hits = Physics2D.Raycast(curr, dir, filter, results, distance);
for (int j = 0; i < hits; i++)
{
Collider2D intersection = results[j].collider;
if (intersection != collider)
{
intersections.Add(intersection);
}
}
}
return intersections;
}
}
EdgeColliderChecker:
public class EdgeColliderChecker : MonoBehaviour
{
public EdgeCollider2D e1;
void Update ()
{
List<Collider2D> hits = e1.GetInterSections();
if (hits.Count > 0) {
Debug.Log(hits.Count);
}
}
}
Still nothing. Even though the points i calculate align perfectly with the collider:
I did the math for it and it seems to work ok, not tested very thorougly. The intersection check is a bit choppy if it is run while the colliders are moving around:
public class Line {
private Vector2 start;
private Vector2 end;
public Line(Vector2 start, Vector2 end)
{
this.start = start;
this.end = end;
}
public static Vector2 GetIntersectionPoint(Line a, Line b)
{
//y = kx + m;
//k = (y2 - y1) / (x2 - x1)
float kA = (a.end.y - a.start.y) / (a.end.x - a.start.x);
float kB = (b.end.y - b.start.y) / (b.end.x - b.start.x);
//m = y - k * x
float mA = a.start.y - kA * a.start.x;
float mB = b.start.y - kB * b.start.x;
float x = (mB - mA) / (kA - kB);
float y = kA * x + mA;
return new Vector2(x,y);
}
public static bool Intersects(Line a, Line b)
{
Vector2 intersect = GetIntersectionPoint(a, b);
if (Vector2.Distance(a.start, intersect) < Vector2.Distance(a.start, a.end) &&
Vector2.Distance(a.end, intersect) < Vector2.Distance(a.start, a.end))
{
return true;
}
return false;
}
}
public static class EdgeColliderExtentions
{
public static bool Intersects(this EdgeCollider2D collider, EdgeCollider2D other)
{
Vector2[] points = collider.points;
Vector2[] otherPoints = other.points;
for (int i = 0; i < points.Length - 1; i++)
{
Vector2 start = collider.transform.TransformPoint(points[i]);
Vector2 end = collider.transform.TransformPoint(points[i + 1]);
Line line = new Line(start, end);
for (int j = 0; j < otherPoints.Length - 1; j++)
{
Vector2 otherStart = other.transform.TransformPoint(otherPoints[i]);
Vector2 otherEnd = other.transform.TransformPoint(otherPoints[i + 1]);
Line otherLine = new Line(otherStart, otherEnd);
if (Line.Intersects(line, otherLine))
{
return true;
}
}
}
return false;
}
}
But I'd really like to use something provided by unity instead.

Use Collider.bounds.Intersects(Collider.bounds) to determine if two bounds are intersecting:
void Update () {
if (e1.bounds.Intersects(e2.bounds)) {
Debug.Log("Bounds intersecting");
}
}
This unfortunately won't let you know if the edges are intersecting. However, if this tests false, you can skip testing the edges.

I realized that i could exhange one of the edge colliders for a polygon collider for my use case.
Using a polygon and an edge collider with Collider2D.OverlapsCollider() works as expected.
I don't know if i should accept this as an answer or not because it does not solve the original question about finding a funciton in unity for line intersection.

You could get a relatively close approximation with the following:
You could create a script that adds several small box colliders evenly along the line, the more the better. And then just do normal collision detection. But the more boxes (higher precision), the more costly computation-wise.

Unity3D - C# 360 Orbital Camera Controller (Gimbal Lock Issue)

I have a stationary cube in my scene that I'm orbiting a camera around. I have my MainCamera nested under a GameObject that I'm calling 'OrbitalCamera'.
I setup the script so that a click (or tap) and drag will rotate the camera around the object in space so it feels like you're rotating the cube (ie: if I click the top of a face on the cube, and pull down, I'm rotating the X value) but you'll actually be rotating the camera.
For the most part, my script works. However, after rotating the Y so much, the camera is upside down and the X gets inverted. Here's my script:
public class OrbitalCamera : MonoBehaviour {
public bool cameraEnabled;
[SerializeField] private float touchSensitivity;
[SerializeField] private float scrollSensitivity;
[SerializeField] private float orbitDampening;
protected Transform xFormCamera;
protected Transform xFormParent;
protected Vector3 localRotation;
protected float cameraDistance;
void Start () {
cameraEnabled = true;
xFormCamera = transform;
xFormParent = transform.parent;
cameraDistance = transform.position.z * -1;
}
void LateUpdate () {
if (cameraEnabled) {
// TODO:: FIX PROBLEM WHERE WHEN CAMERA IS ROTATED TO BE UPSIDEDOWN, CONTROLS GET INVERSED
if (Input.GetMouseButton(0)) {
if (Input.GetAxis("Mouse X") != 0 || Input.GetAxis("Mouse Y") != 0) {
localRotation.x += Input.GetAxis("Mouse X") * touchSensitivity;
localRotation.y -= Input.GetAxis("Mouse Y") * touchSensitivity;
}
}
}
Quaternion qt = Quaternion.Euler(localRotation.y, localRotation.x, 0);
xFormParent.rotation = Quaternion.Lerp(xFormParent.rotation, qt, Time.deltaTime * orbitDampening);
}
}
Is there a good method to achieve this type of 360 camera? I'd like dragging from right to left to always move the camera left and dragging left to right to always move the camera right -- no matter how the camera is oriented.

Perhaps you could clamp the above/below pan at 89 degrees?
I recently helped a friend make a mouse gimbal, and found allowing freedom beyond 89 degrees was problematic and unnecessary. It seems like your application is the same, at least for one of the two planes.
In your LateUpdate() call, you could perhaps add:
localRotation.x += Input.GetAxis("Mouse X") * touchSensitivity;
localRotation.x = Clamp(localRotation.x);
Then, of course, create your clamp function, which should be fairly straight forward:
float Clamp(float val) // prevent values from ~90 - ~270
{
int lowVal = 89;
int highVal = 271;
int midVal = 180;
if (val > lowVal & val < highVal)
{
if (val > midVal) val = highVal;
else val = lowVal;
}
return val;
}
A slightly different application, but I'm sure you can see how I've set this up: I apply rotation in two steps. Step 1 - a simple Rotate() call, Step 2 - clamping some/all of the rotation:
using UnityEngine;
public class MouseGimbal : MonoBehaviour
{
[SerializeField] [Range(0,89)] float maxRotationDegrees = 10.0f; // At 90+ gimbal oddities must be dealt with.
[SerializeField] bool ClampToMaxRotationDegrees = true; // Disable for free rotation.
[SerializeField] float rotationSpeed = 10.0f;
const float fullArc = 360.0f;
const float halfArc = 180.0f;
const float nullArc = 0.0f;
void Update () { Tilt(); }
void Tilt()
{
// Apply the 'pre-clamp' rotation (rotation-Z and rotation-X from X & Y of mouse, respectively).
if (maxRotationDegrees > 0) { SimpleRotation(GetMouseInput()); }
// Clamp rotation to maxRotationDegrees.
if (ClampToMaxRotationDegrees) { ClampRotation(transform.rotation.eulerAngles); }
}
void ClampRotation(Vector3 tempEulers)
{
tempEulers.x = ClampPlane(tempEulers.x);
tempEulers.z = ClampPlane(tempEulers.z);
tempEulers.y = nullArc; // ClampPlane(tempEulers.y); // *See GIST note below...
transform.rotation = Quaternion.Euler(tempEulers);
///Debug.Log(tempEulers);
}
float ClampPlane(float plane)
{
if (OkayLow(plane) || OkayHigh(plane)) DoNothing(); // Plane 'in range'.
else if (BadLow(plane)) plane = Mathf.Clamp(plane, nullArc, maxRotationDegrees);
else if (BadHigh(plane)) plane = Mathf.Clamp(plane, fullArc - maxRotationDegrees, fullArc);
else Debug.LogWarning("WARN: invalid plane condition");
return plane;
}
Vector2 GetMouseInput()
{
Vector2 mouseXY;
mouseXY.x = -Input.GetAxis("Mouse X"); // MouseX -> rotZ.
mouseXY.y = Input.GetAxis("Mouse Y"); // MouseY -> rotX.
return mouseXY;
}
void SimpleRotation(Vector2 mouseXY)
{
Vector3 rotation = Vector3.zero;
rotation.x = mouseXY.y * Time.deltaTime * rotationSpeed;
rotation.z = mouseXY.x * Time.deltaTime * rotationSpeed;
transform.Rotate(rotation, Space.Self);
}
void DoNothing() { }
bool OkayHigh(float test) { return (test >= fullArc - maxRotationDegrees && test <= fullArc); }
bool OkayLow(float test) { return (test >= nullArc && test <= maxRotationDegrees); }
bool BadHigh(float test) { return (test > halfArc && !OkayHigh(test)); }
bool BadLow(float test) { return (test < halfArc && !OkayLow(test)); }
}

When I developed an orbital camera, I created 3 objects:
- x_axis (rotate with vertical mouse moviment)
- y_axis (rotate with horizontal mouse moviment)
- camera (look_at object) (translated Vector3(0,0,-10))

Rotation over time in 3D

Im working with Xna 4, doing a game where i have a game object (spaceship) that moves in a 3D world on the Y axis = 0 plane.. Aka 2.5D..
Until now i used a very complex angle calculation to create a rotation between 2 vectors, yet that algorithm lacks the ability to take into account that the object already is rotated. so the results get funkey..
Therefore i was hoping that someone, could show me a smart and easily implementable way to use Matrices and vector math, to do such a rotation over time thingy.
What i noticed in previous searches, is that people have the following variables in their object classes:
- Position vector3
- right vector3
- up vector3
- Rotation matrix
- transformMatrix matrix
- velocity vector3
- etc..
often i ask myself why its needed to have that many variables for a simple current position.. or maybe im not understanding.. anyways..
I have the position, rotation and transformsMatrix currently, and would like to know what else i need and HOW to calculate it, and then how you would implement JUST the rotation over time.
The method that is called by my right-click movement command trig sends a vector3 position on the Y = 0 plane of where the click happened.
public void MoveCommand(Vector3 pos){ }
ive tested this, and the "pos" given is accurate. Any help will be apreciated ..

You should check the Matrix.CreateRotationX Y or Z acording to the rotation that you want.
X,Y or Z is the axis of the rotation,
If you choose Y you will see a "2D" rotation (yaw) because that is the axis that you are using as depth.
If you choose X or Z axis you will see "3D" rotations (pitch and roll)
The code should look like this:
WorldMatrix = Rotations * Translation
where
Rotations = Matrix.CreateRotationX(angleRadians)
and
Translation = Matrix.CreateTranslation(Position);
The world matrix is the matrix that is affecting your model, the view and projection depends on the camera
Now if you want to know the angle between vectors you should check the dot product or the atan2 function because you are in 2D

Vector3 Position;
float Rotation;
Matrix World
{
get
{
return Matrix.CreateRotationZ(Rotation) * Matrix.CreateTranslation(Position);
}
}
public void RotateInstantly(Vector3 position)
{
Rotation = Math.Atan2(Position.Y - position.Y, Position.x - position.x);
}
public void RotateIncremently(Vector3 position, float maxStep)
{
float targetRotation = Math.Atan2(Position.Y - position.Y, Position.x - position.x);
float diff = targetRotation - Rotation;
if (Math.Abs(diff) > maxStep)
{
if (targetRotation > Rotation)
Rotation += maxStep;
else
Rotation -= maxStep;
}
else
Rotation = targetRotation;
}
You can use the RotateIncremently like this:*
float dt = (float)gameTime.ElapsedGameTime.TotalSeconds;
float maxRotationVelocity = Math.TwoPi; //2* Pi is one revolution.
RotateIncremently(target.Position, maxRotationVelocity * dt);

Thanks to Stig-Rune Skansgård's reply (if your danish hi5), i fixed my old Angle calculation and got it to work in every case.. So i thought i would answer my own question with the solution that works for me, so that future visitors can benefit of it.. This is a snippet of a very large Ship class + a helper method to calculate the angle:
public static float CalculateAngleFromVectors(Vector3 v1, Vector3 v2) {
float x = 0;
float X = v2.X - v1.X,
Z = v2.Z - v1.Z;
if (Z == 0) {
x = (X < 0 ? 90 : 270);
} else if (X == 0) {
x = (Z < 0 ? 180 : -180);
} else {
float temp = MathHelper.ToDegrees((float)Math.Atan(X / Z));
if (X < 0) {
x = (Z < 0 ? Math.Abs(temp) : 180 - Math.Abs(temp));
} else {
x = (Z < 0 ? 360 - Math.Abs(temp) : Math.Abs(temp) + 180);
}
}
return x;
}
this method gets you the float angle (in degrees) to rotate your ship (from the standard 0 degrees starting point)..
to use it, simply make some update / animation method in your class that does something like this:
float desiredRotation = 0, currentRotation = 0, totalElapsed = 0, timePerFrame = 0.05f;
if (desiredRotation != 0) {
totalElapsed += elapsed;
if (totalElapsed > timePerFrame) {
if (isRotationComplete()) {
rotX += MathHelper.ToRadians(desiredRotation);
currentRotation = desiredRotation = 0;
} else if (desiredRotation > currentRotation) {
currentRotation += shipTurnSpeed;
} else if (desiredRotation < currentRotation) {
currentRotation -= shipTurnSpeed;
}
totalElapsed -= timePerFrame;
}
}
EDIT: and the completion check:
private bool isRotationComplete() {
bool b = false;
if (desiredRotation > currentRotation && currentRotation + shipTurnSpeed > desiredRotation) {
b = true;
} else if (desiredRotation < currentRotation && currentRotation - shipTurnSpeed < desiredRotation) {
b = true;
}
return b;
}
essentially what this does is to always check wether or not DesiredRotation is bigger than 0.. if it is, then that means the player has given the command to rotate (or the AI).. CurrentRotation in my example is ofc how much has been rotated since a rotation command was last given, and is set to 0 once the rotation is complete.. You should have a Rotations matrix that uses a different variable to display the rotation with.. mine is this:
public float rotX { get; set; }
public float rotY { get; set; }
public Vector3 position { get; set; }
public Matrix Transform {
get {
return (Matrix.Identity *
Matrix.CreateScale(scale) *
Matrix.CreateRotationY(MathHelper.Pi) *
Rotation *
Matrix.CreateTranslation(position));
}
}
public float ShipCurRotation { get { return (rotX + MathHelper.ToRadians(currentRotation)); } }
public Matrix Rotation { get { return (Matrix.CreateRotationY(ShipCurRotation) * Matrix.CreateRotationX(rotY)); } }
The rotX variable is set in my animation when the rotation is complete, and also at Init.. And here is how i use the rotation angle that my first code snippet generates for me:
public void MoveToPosition(Vector3 pos) {
desiredRotation = (CalculateAngleFromVectors(position, pos) - MathHelper.ToDegrees(rotX));
isMoving = true;
}
.. this makes a smooth customizable rotation, transforms and movement setup.. In a XZ plane ofc.. the Y axis is UP and always 0..
Feel free to comment on this, if you have suggestions or changes or ideas to make things even better.. Im always open for improvements.. Thanks for the replies, and hope this helps alot of new developers, took me forever to gather this stuff from the web..
PS. the rotation can be applied directly to rotX for an instant rotation, bypassing the animation and turnspeed..
WithRegards
MatriXz