Get result of add impulse if object was not moved - unreal-engine4

So, lets say my character has the ability to push "movable" objects. This is alredy implemented and working as desired.
But I want to make the characher be pushed back if he tries to push an object that is hitting a wall or an immovable object, is there a way to see if my add impulse had any effect?
Or a best way to do is some ray casts on the movable object boundaries to see if is touching any other thing?

For characters you can use Launch Character. It's like adding velocity giving a specific direction. Add Impulse is intended to be used with Objects that simulate physics.
Just Launch the Character to a direction opposite the direction it's touching. You can use Dot Product between Character Velocity and the Object Face (forward).

Related

How do I partent an object to a bone in the blender hierarchy?

So, I'm trying to make a simple RPG game using Blender and Unity. I would like to have an empty object to be used as a weapon holding position parented to my right hand bone so that I can switch weapons in and out and they'll be able to animate along with my character by being the child of the empty position. The problem I am having is that I can't get the empty position to be a child of the specific right hand bone, only the armature. Is there a way to make this work? Also, if this isn't a good procedure to accomplish what I am trying to do, please enlighten me with the proper way, I'm kind of a noob, thanks.
If you have assigned your bones correctly on your character, you should be able to add additional game objects into the joints of the character, ie. Swords, shields and other cool things.
Then you can use this code to quickly fetch specific defined bones:
_playerAnimator.GetBoneTransform(HumanBodyBones.LeftHand);
Which gets the bone transform.
Here is a quick snippet of the assigned bones using a PlayerAvatar on character.

Unity 2D Bounce Back moving object when colliding with another object

I have an object that, after receiving its respective input, it moves this way:
mov = new Vector3((Input.GetAxis("Horizontal") * vel), 0, 0);
transform.position += mov;
But, I want it to bounce back, once it collides with an object.
I´ve made the procedures already (OnCollisionEnter2D(Collsion2D col){bla bla...}), but I need help with what happens on the collision (bouncing back the object)....
I´ve tried giving the collided object a bouncing material, but it just slows it a bit, my guess is that because of the constant force given by the acceleration.
Greetings.
If you move the object with transform.position what you are doing is basically a "teleport" so it will ignore the bouncing material. If you want it to bounce you have to write the physics code to detect a collision and change the movement or you can do addforce to move the object and it will detect collisions and react automatically.
you are teleporting the object at the current time. instead you should use the Rigidbody.addForce this will add a force in the specified direction thus if you do the opposite direction will "bounce" of the object. Another option would be to create a physics material then not bother with the code.
You are not using materials, right?
See if the content of this post may help you, the OP is using a formula using Raycast and the answer guides him to use the Raycast with Layers Maks:
2D bouncing formula doesn't work properly
There is this one also with fixed angles (like Pong), but it uses material (with values: friction: 0, bounciness: 1):
https://gamedev.stackexchange.com/questions/70294/get-gameobject-to-bounce-of-colliders
But if nothing makes sense and you are going crazy and might want to start from zero, there is this official video tutorial on bouncing and sliding in 2D:
https://unity3d.com/learn/tutorials/modules/beginner/2d/sliding-bouncing-2d

Unity3d - check for collision on non moving objects

I have a sphere build from multiple objects. What I want to do is when I touch/click an object, that object should find all adjunctive objects. But because none off them are moving, no collision detection can be used.
I can't find a way to detect these adjunctive objects even when the colliders do collide with each other, as I can see that in the scene. I tried all the possibilities, but none off them are working, because no objects are moving.
Is there a way to check for manual collision detection, or is there some sort of way to let Unity3d do the collision detection automatically?
You could keep a list of all those objects, then when your event happens you can send messages to all them to do what you want them to do.
Lets assume you want your sphere to break into little pieces. You send a Force message to the sphere. Then you use Newton's Laws of motion and find out how much velocity each piece gets. Remember velocity is a vector thus it has direction.
This is how I would do it and still keep the right amount of control over what happens in my game/simulation. Remember F = ma.
you could use RaycastHit (http://docs.unity3d.com/Documentation/ScriptReference/RaycastHit.html) for your collision, this also works on non-moving objects but it needs more performance
You can add rigidbody to every objects; when you touch one of them, give a force onto it, then it is going to move and trigger event of the adjacent objects.
for the reason you do not want to move the object you touch, you can cancel movement in the OnCollider or OnTrigger event handler function.
I managed to work around this by checking the distance from the selected object and all other objects that are part of the sphere. If the distance is below a certain value, then it is an adjunctive object.
Although this is certaintly not fool proof, it works without problems so far.
I am sorry I was not clear enough. Thanks for all the advice what so ever.

How to make object fall in line with the target when applying wind effect?

I am making a paper toss kind of game in Unity3d. I am implementing wind effect using constant force. I wanted to know how to make object fall in line with the target ie, if the object gets over the target, it should go in or fall in line with the target, not go behind or in front of the target. At present when I swipe applying a constant force, for different angles of swipe the distance moved by the object differs. Help would be much appreciated.
In FixedUpdate, use Physics.Raycast to check to see if the object is over the target. If so, set the x and z values of rigidbody.velocity to be zero (assuming y is the up/down axis in your game world) and disable the ConstantForce component (i.e. gameObject.GetComponent<ConstantForce>().enabled = false). Note that this won't be most realistic of movements, as it will seem like the object suddenly moves straight down when it goes over the target -- but it sounds like that's what you want.

Collision Detection between two rectangles

Fairly simple question that Im sure you will laugh at me for.
I have two rectangles playerRect and wall.
I have an if statement with the condition being ..
if (CGRectIntersectsRect(playerRect,wall)) {
//handle collision here
}
The problem I'm having is working out which side actually hit the wall rectangle.
I need to know because then I stop te player from moving depending on which side hit.
Thanks for any help
Disco
I would add some direction property to my 'Player' object. This way when you detect a collision, you just check to see which way the player was moving prior to the collision and react accordingly.
Create a CGRect for each side of your object with just a width of 1 (or height of 1 depending on the side) and look for intersections with the sides instead of the entire object. If your object is moving faster than 1 pixel per collision check, then you would check the sides in addition to checking the entire object