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Detecting overlapping polygon2D colliders in Unity

I'm trying to program an isometric building placement script. Each building has a PolygonCollider2D component on it with a trigger. When placing a new building, I'm trying to check if the PolygonCollider2D of the placed building overlaps with anything else (to check if placement is valid). My code is as follows:
Adjust the points of the new placed building collider based on the mouse position
Vector2[] points = polygonCollider2D.points;
points.SetValue(polygonCollider2D.points[0] + (Vector2)mousePosition, 0);
points.SetValue(polygonCollider2D.points[1] + (Vector2)mousePosition, 1);
points.SetValue(polygonCollider2D.points[2] + (Vector2)mousePosition, 2);
points.SetValue(polygonCollider2D.points[3] + (Vector2)mousePosition, 3);
polygonCollider2D.points = points;
Set up contact filter:
ContactFilter2D contactFilter2D = new ContactFilter2D();
contactFilter2D.useTriggers = true;
contactFilter2D.SetLayerMask(polygonCollider2D.gameObject.layer);
Check for collisions
List<Collider2D> list = new List<Collider2D>();
Debug.Log(polygonCollider2D.OverlapCollider(contactFilter2D, list));
However if there is already a building there, it still does not register an overlap.
What am I missing / doing wrong ?
Thanks so much for the help!

Your code which sets the polygon collider points seems to be the issue here. If that code runs multiple times, it will repeatedly offset the collider further and further away from its original position. You probably don't want to be changing the actual collider; usually you should move object which has the collider. So you would replace those lines with something like this:
gameObject.transform.position = mousePosition;

Moving and scaling an object according to hand position

I need some help with my college project. I have a cylinder and need it to act as a coil. For example, if I touched the cylinder's surface it's height will decrease (scaled in the y direction) as if pressing on a coil then when I remove my hand it returns back to its original size.
This is what I reached till now but I still have some problems that I can't solve.
public class Deformation : MonoBehaviour
{
Vector3 tempPos;
private void InteractionManager_SourceUpdated(InteractionSourceUpdatedEventArgs hand)
{
if (hand.state.source.kind == InteractionSourceKind.Hand)
{
Vector3 handPosition;
hand.state.sourcePose.TryGetPosition(out handPosition);
float negXRange = transform.position.x - transform.localScale.x;
float posXRange = transform.position.x + transform.localScale.x;
float negYRange = transform.position.y - (transform.localScale.y / 2);
float posYRange = transform.position.y + (transform.localScale.y / 2);
float negZRange = transform.position.z - transform.localScale.z;
float posZRange = transform.position.z + transform.localScale.z;
float handX = handPosition.x;
float handY = handPosition.y;
float handZ = handPosition.z;
if ((negXRange <= handX) && (handX <= posXRange) && (negYRange <= handY) && (handY <= posYRange) && (negZRange <= handZ) && (handZ <= posZRange))
{
tempPos.y = handPosition.y;
transform.localScale = tempPos;
}
else
{
tempPos.y = 0.3f;
transform.localScale = tempPos;
}
}
}
// Use this for initialization
void Start()
{
tempPos = transform.localScale;
InteractionManager.InteractionSourceUpdated += InteractionManager_SourceUpdated;
}
I attached two scripts to my object (cylinder) the TapToPlace script from the HoloToolKit and the deformation script stated above. The problem is when I deploy to my HoloLens to test, when I place the cylinder first to the needed place then try to deform it after that, it is placed but not deformed. If I tried it the other way around both work. Any ideas why does the deformation script does not work after the TapToPlace one?
The cylinder when viewed by my HoloLens is somehow transparent. I mean that I can see my hand through it. I need it to be more solid.
I wonder if there is something like a delay that I can use because when I use the deformation script stated above the cylinder is scaled to my hand position then scaled back to its default size very fast and appears as if blinking.
At first I place the cylinder on a setup (something as a table for example) then I begin to deform it. When I commented the else part in the deformation script stated above, it was scaled and left stable without returning to the original size. It is scaled symmetrically so its height is decreased from up and down resulting in the base of the cylinder becomes away from the table. I need the base of the cylinder to be always stable and touching the table under it.
Note: I am using Unity 2017.3.1f1 (64-bit) - HoloToolkit-Unity-2017.2.1.3
Thank you in advance.

1) Did you see the MRTK 2017.2.1.4 release? It has some useful features such as two handed resizing/scaling of objects. The BoundingBox code in the new MRTK release does moving and resizing in one component, it might be a better base to start from than the TapToPlace, or at least show how the two types of transform can work together.
2) What colour is your object? Hololens will render black as transparent, so try making the object bright white for testing. Also, just double check the brightness is turned up to full (the LHS buttons on the hololens). Finally, check your shader is the MRTK Standard shader. (again, the 2017.2.1.4 release has new shader code you might want to try.) . In a room without direct sunlight it should pretty much cover up your hand.
4) I'm not sure I follow completely, but the pivot point could be important here. If it is centred in the middle of the coil (as I'd imagine it is) then when you deform the coil down it will still stay centered at that central pivot point.
If you instead set the pivot point to the bottom of the coil, touching the table, you can scale and that point stays on the table and the top does all the moving.

Moving a cardboard around

Quick disclaimer: I am not a very advanced C# user, being more accustomed to languages like python, so i apologise if the answer is right in front of me.
I've been making a little game for the Google Cardboard, Using the demo scene as a base. I've got some code that checks for a "Trigger Pull" and then should translate the Cardboard cameras up by 10 units.
//Checks For Magnet Trigger
if (Cardboard.SDK.Triggered)
{
//moves player up at a rate of 10u/s
transform.Translate(Vector3.up * 10);
Debug.Log("Triggered_Head");
//Tell Cardboard to maintain new position
}
Currently this works really well for detecting the magnet pull, and it does translate the cardboard. The problem is that almost immediately after translation the cardboard gets teleported back to the base position.
Currently i have this code inserted into the UpdateHead() method (?) from CardboardHead.cs, like so:
// Compute new head pose.
private void UpdateHead() {
if (updated) { // Only one update per frame, please.
return;
}
updated = true;
Cardboard.SDK.UpdateState();
if (trackRotation) {
var rot = Cardboard.SDK.HeadPose.Orientation;
if (target == null) {
transform.localRotation = rot;
} else {
transform.rotation = target.rotation * rot;
}
}
if (trackPosition) {
Vector3 pos = Cardboard.SDK.HeadPose.Position;
if (target == null) {
transform.localPosition = pos;
}
else {
transform.position = target.position + target.rotation * pos;
}
//Checks For Magnet Trigger
if (Cardboard.SDK.Triggered)
{
//moves player up at a rate of 10u/s
transform.Translate(Vector3.up * 10);
Debug.Log("Triggered_Head");
//Tell Cardboard to maintain new position
}
}
if (OnHeadUpdated != null) {
OnHeadUpdated(gameObject);
}
}
Doing this does everything right, but the location is reverted almost instantly (in the next frame i assume). So my question is: How do i make the transform stick, and is there a better way for me to handle this?

Alright, i figured out how to handle movement, and I'm posting the solution here for anyone in the future who can't figure it out. Quick note: I did update to the latest version of the SDK, although that shouldn't make a difference, except for naming.
So, Step 1:
Create an object to use as your controller. I just used one of the prototyping cubes from an asset pack, but whatever will work (empty objects would be best).
Place this object more or less in the center-point of the two cameras.
Parent your GvrMain object to the controller object (by dragging it onto the controller object) as well as any other components you want to move with the player (Guns, GUI's, etc)
Step 2:
Create a script for the controller object.
In the Update() method, add the lines:
if (GvrViewer.Instance.Triggered)
{
transform.Translate(Vector3.up)
}
for older versions replace GvrViewer.Instance with Cardboard.SDK
Customise your movement to your liking, any normal unity functions should work.
Some shortcomings:
You have to repeatedly press the trigger, using while() seems to break unity. This seems pretty easy to fix
The code snippet instantly translates up by 1. Not sure how to do it as a steady acceleration.
Hopefully this helps anyone who had my problem.

Make GameObject “attach” properly?

This script makes a cube "stick" to whatever it collided with. The problem is that when it's going at relatively high or medium speeds (or when the device itself is slow), the cube tends to "get a bit inside" what it collided with and then stick to it. What changes do I have to make to fix this?
In order for this script to work, one GameObject must have bool _sticksToObjects = true; and the other bool _sticksToObjects = false;
I have tried turning the Rigidbody's Collision Detection mode to either Continuous or Continuous Dynamic
I think my script depends on frame rate. That may be where the problem lies.
Normal "Attach":
Abnormal "Attach":
Rigidbody _rigidBody;
Transform _meshTransform;
bool _sticksToObjects = true;
public Transform _stuckTo = null;
protected Vector3 _offset = Vector3.zero;
void Awake()
{
GameObject CubeMesh = GameObject.FindWithTag ("CubeMesh");
GameObject Cube = GameObject.FindWithTag ("Cube");
_rigidBody = Cube.GetComponent<Rigidbody> ();
_meshTransform = CubeMesh.GetComponent<Transform> ();
}
void Update()
{
if (_stuckTo != null)
{
transform.position = _stuckTo.position - _offset;
}
}
void OnCollisionEnter(Collision collision)
{
if (!_sticksToObjects) {
return;
}
_rigidBody.isKinematic = true;
// Get the approximate collision point and normal, as there
// may be multipled collision points
Vector3 contactPoint = Vector3.zero;
Vector3 contactNormal = Vector3.zero;
for (int i = 0; i < collision.contacts.Length; i++) {
contactPoint += collision.contacts [i].point;
contactNormal += collision.contacts [i].normal;
}
// Get the final, approximate, point and normal of collision
contactPoint /= collision.contacts.Length;
contactNormal /= collision.contacts.Length;
// Move object to the collision point
// This acts as setting the pivot point of the cube mesh to the collision point
transform.position = contactPoint;
// Adjust the local position of the cube so it is flush with the pivot point
Vector3 meshLocalPosition = Vector3.zero;
// Move the child so the side is at the collision point.
// A x local position of 0 means the child is centered on the parent,
// a value of 0.5 means it's to the right, and a value of -0.5 means it to the left
meshLocalPosition.x = (0.5f * contactNormal.x);
_meshTransform.localPosition = meshLocalPosition;
if (_stuckTo == null || _stuckTo != collision.gameObject.transform) {
_offset = collision.gameObject.transform.position - transform.position;
}
_stuckTo = collision.gameObject.transform;
}
Here are some screenshots of the Unity editor:

This is a well-known category of problem in game engineering and you'll be pleased to know the solution is relatively simple. You'll be pleased to hear there are similar, but much more complicated, problems that are actually solved in the same way. I'll try to explain.
Now here's the thing. It's quite often that the following question comes up...
So I'm working on GTA. I have a humanoid, H, running around. She approaches vehicle V. She opens the door and gets in and drives off. After that everything goes to hell in Mecanim and all the code stops working. What to do?
Surprisingly, the way that is done in games is:
Surprisingly: you actually swap to totally different models at that point!!!!!
You have H and V in the game. But then you have an animation (say) for H climbing in to V. But then, you literally destroy the game objects of H and V, and you Instantiate (or just awake) a new, totally different, game object, which is D ("a car being driven around by a lady").
(If you think about it, you can see that when you do this, you carefully adjust all the stuff in D, so that it matches what was "just then happening" in the frame, in relation to both H and V. So for example, literally, you copy the transform, twist etc of the car V, to the new car-inside-D, if lady H has the SmearedMakeupEffect, you put the same SmearedMakeupEffect on the lady-within-D, you position all the bones identically, and so on.)
Another simple example of this is, you often get people asking, "my character C gets killed and I want it to become a ragdoll, how to?" In fact you just swap to a totally new game object you have all set up for that passage of the game. Indeed, if you have a character A ("Arnie") in a game, it's normal that you have 4 or 5 "different As" sitting offside the stage, so, there's "ragdoll A", "A who can dance" "A with weapon". And indeed many of these are combos, you know "A on the horse" "A in the car" and so on.
So interestingly, the "real" solution here is,
once they become a new connected thing, destroy them both and swap to a new game object altogether!
if you have made games "until you are blue in the face" from making games, this is just what you would do as a matter of course. Even though its' a simple situation, it's just easier in the long run. After all, consider all the stuff you have to do when this happens:
make hitting object child of the other
turn off physics on the child
change the way your physics works for the whole thing
turn off or change the collider on the hitting object, perhaps making it part of the overall object
you'll likely have some sort of new "separation" physics where it can be knocked-off - you'd have to turn all that on
likely change minor issues like sound effects, colors etc
As you can see it's a huge chore doing all this stuff, and indeed it's one of those things it's just "easier to do properly" and change to a new model.
All that being said, I know you want a Quick Script Solution you can Paste In :) Here it is...
Step 0, You'll create "YourScript" which goes on the "main" cube. it will "catch" another cube moving around.
YourScript will look basically like this ...
[System.NonSerialized] public bool isConnectedNow;
void OnCollisionEnter(Collision collision)
GameObject theThingWeCaught = collision.gameObject
Debug.Log("We caught this thing .. " + theThingWeCaught.name)
// make it a child of us......
theThingWeCaught.transform.parent = transform
theThingWeCaught ... set kinematic
theThingWeCaught ... probably disable the rigidbody
theThingWeCaught ... probably disable the collider
isConnectedNow = true;
That's really all you have to do.
Step 1, YOUR script must have a public bool like this
[System.NonSerialized] public bool isConnectedNow;
Step 2, Here's MyScript which goes on the hitting cube, first we'll unit-test that your isConnectedNow bool is working
public Class MyScript:MonoBehaviour // attach to the "child" cube
{
public float correctXDistance;
public float correctYDistance;
public Transform bigCube;
public YourScript yourScript;
void Update()
{
string message = yourScript.isConnectedNow ? "free" : "stuck";
Debug.Log("I am " + message);
}
}
attach, debug, and run. Make the little cube stick and unstick from the big cube .. Watch the console. it works? So add this to MyScript
private void DistanceCorrectionX()
{
float xDistance = bigCube.position.x - transform.position.x;
float xSign = Mathf.Sign(xDistance);
float xDelta = Mathf.Abs(xDistance);
float closenessPercentage = (xDelta/correctXDistance)*100f;
if ( closenessPercentage<90f || closenessPercentage>110f)
{
// they are not close enough to quantize on this axis
// this comes in to play when you have multiple axes
return; // do nothing.
}
float xShouldBe = bigCube.position.x + xSign * correctXDistance;
Vector3 p = transform;
p.x = xShouldBe; // be careful it's .y, .z etc for other axes
transform.position = p;
}
for now call that in Update() in MyScript like this
void Update()
{
Debug.Log("I am " yourScript.isConnectedNow ? "free" : "stuck");
if (yourScript.isConnectedNow) DistanceCorrectionX();
}
Now actually Play and make it stick. Now, since it's running in Update simply while Play look at the Inspector for MyScript and adjust the value of correctXDistance to get the exact look you want. When yo have decided on a value, unPlay and put that in as the final value you wish.
Next, in DistanceCorrectionX simply duplicate all the code and do it again for the Y axis DistanceCorrectionX. If you also do Z, do that.
Finally. Note you will have a lot of messy code, like this...
void Update()
{
// handle all the DistanceCorrectionX etc as seen above.
if (yourScript.isConnectedNow)
{
.. turn off the collider on me
}
else
{
.. turn on the collider on me
}
}
and so on, there's "many little things" you'll need to do.
Don't forget also, overwhelmingly you may want to make the hitting object a child of the big object, depending on your situation. (Then of course they would move around together as a unit.)
Note that in the positioning code above I just showed it as position, not local position, for pedagogic clarity. If you want to do them flinging around, and spinning and so on, you'd make the hitting object a child of the other and you would use localPosition in the same way. Enjoy.

One possible way that comes to my mind is:
Inside of the "collision enter" check the distance between these objects and move the one that should stick to the other one a bit away.
As you see in the picture the distance between A and B should be equal to the sum of the widths divided by 2 (with a small threshold of course).
If the distance is less than the sum of the widths / 2 then you have an abnormal "attach" and you have to move one of the objects away. Its not really difficult to accomplish that.

Jump animation using animation class

I need a little help in my little 2D game I want to create in XNA. I had almost no knowledge of programming before I got interested in XNA and C#, so maybe my problem is simple, but I just can't figure it out.
So basically, I have a base class, and I created an additional class Animation for animating sprites. I implemented some methods so that when the player presses "right" it would change the animation's current texture and increment X by a number of xf; anyway, the main idea is that I'm using just one instance of my class (basically, one object of type animation which changes its texture and properties based on what key is pressed).
So, I had no problems making it run right or left. Works out pretty well. The big problem started when I wanted to implement the jump sprite. So I created the 6 frames necessary for the sprite, but to animate it I have virtually no idea how to do it.
The only thing it does right now is to loop through the frames of the sprite, but the position (both .X and .Y) remain the same. The thing is, I have a Vector2 position which holds the animation's current position, and it's fine with running because I simply increment it. However, when it comes to jumping, I want it to increment .X, but the .Y should be decremented (thus going up) until frame number 3; after frame number 3, until the last frame, I want the .Y position to go down (thus fall) with the corresponding animations (erm, frames).
So, basically, I don't know how to modify the .X and .Y so that it would display the frames that I need in the time I need. I don't know if you really understood what I'm trying to say; basically when I press the "up" key, it loops through the frames but the position remains the same.
My idea was to use a reference to the actual Vector2 position which holds the animation's current position and pass it to the method in the other Animation.cs class, namely the PlayAnimJump, and modify the position after each frame and return it to the actual Game1.cs by reference. Even if I would do that (though I fail to see what good it would be), it wouldn't be updating the position as it should. So, any ideas?
Here is the code for the PlayAnimJump method from the Animation class:
public void PlayAnimJump(GameTime gameTime)
{
elapsed += (float)gameTime.ElapsedGameTime.Seconds;
sourceRect = new Rectangle(currentFrame * frameWidth, 0, frameWidth, frameHeight);
currentFrame = 0;
if (elapsed >= frameTime)
{
if (currentFrame <=3)
{
if (looping)
{
currentFrame++;
}
}
else if (currentFrame > 3)
{
currentFrame++;
}
elapsed = 0;
}
}
The default constructor for that class:
public Animation(ContentManager Content,string asset,float frameSpeed, int numbOfFrames, bool looping,Vector2 positionIT)
{
this.assetName = asset;
this.frameTime = frameSpeed;
this.numbOfFrames = numbOfFrames;
this.looping = looping;
this.animation = Content.Load<Texture2D>(asset);
frameWidth=(animation.Width / numbOfFrames);
frameHeight=animation.Height;
position = positionIT;
}
Here is the code (from the main) when the up key is pressed:
else if (up)
{
check = animation1.GetAsset();
if (check == "eright")
{
animation1.SetFrameSpeed(0.8f);
animation1.SetNumbOfFrames(6);
animation1.ChangeTexture(Content, "SarimCumVreJiorjica");
animation1.PlayAnimJump(gameTime);
/*position1.x +=2f;
position1.Y -=2f;
*/
}
So, I'm not sure how, but I'm supposed to change position1 according to the frame that's displayed by the animation in that second. Am I missing something?

If your animation class had a reference to the object that you wanted to move (i.e the object holding the position field) then you could modify it within the animation class, within the PlayAnimJump method.
Or, to reduce coupling, you could just have PlayAnimJump return a variable indicating how far into the jump you are (maybe a percentage of the jump, from 0 to 1). Then, you could use the percentage outside to set the objects position. So, if the jump is halfway done, the return value would be 0.5f, which you could use in an equation to determine the players y position. An example equation would be:
float percent = animation1.PlayAnimJump(gameTime);
float y = Math.Sin(percent * Math.PI) * maxJumpHeight;
player.positon.y = y;
This uses a sine wave to determine the players height throughout the jump animation. You would just need to write the code that determines the percentage of the way through the jump (currentFrame) in the PlayAnimJump method and return it.

Formula of the frуefall for Y coordinate is
y = g * t ^ 2 / 2 + v0 * t + y0
Characters jump from height y0 vith start velocity v0 by Y axis and gravity gradually slows down and starts to fall.
Calculate deltaY using following formula
deltaY = g * t ^ 2 / 2 + v0 * t
First show the frame on which the character is pushed off the ground, then the frame on which it rises until it reaches the peak of the jump. Once the sign change deltaY from + to - show how the character change pose for fall. Something like that.