How to make a ball roll like cannonbolt in Unity3D - unity3d

I have this ball that i want to move by rolling like a certain alien, with it spinning on its transform.up to change its direction and rolling on its transform.right to move forward and backward. But as it rolls, its up and right transform vector gets messed up.
In the end, i was unable to find a way to allow it to roll without messing up my directions vector. I have no clue as to how to do this. So yeah, please help. ORZ. By the way, i'm not creating a game using the Ben10 franchise. The ball should act like a wheel... a really round and spherical one.
Note:
I want to use physics in this game. Since, i want it to be able to launch itself off a ramp or something. So, only addforce or addtorque or other relevant functions.

Related

Unity ball friction either too much or not enough

So i am making a simple Golf game, when trying to replicate the balls movement i have noticed that on slopes the ball functions very oddly, it either never stops or stops too quickly and when travelling down slopes will reach a very slow terminal velocity quickly (ie it stops accelerating down slopes). So it either doesnt deaccelerate enough going up a slope or accelerates too slowly going down a slope.
I have been messing about with angular and static Friction of both the ball and the surface to see if that changes it at all and i have also been changing the friction combine of the surface and the ball to see if that makes any difference and so far haven't had any luck.
Is this a common issue with Unity because i haven't been able to find any other questions about it on here. If anyone could give me some advice on how to have my ball not roll forever but still accelerate when going down a slope that would be great
EDIT: The ball has a rigidbody with continous collision, then the course uses a mesh collider. Both however have attached physics materials
The ball is currently just a basic sphere from unity using a sphere collider, i havent tried changing the rigidbody about much yet other than mass. When the ball is hit i addforce to it, the slopes are an asset i have purchased that are perfectly smooth.
Rolling object physics are indeed difficult in game engines.
As I mention in the comment for such questions it's necessary to know (a) what sort of collider and (b) what sort of object it is, since there are at least 4 major approaches to this problem.
But in general you usually have to manually add the "slowing down" function, in a sense representing air resistance.
For a moment set aside the collider choices, and imagine in the abstract you have a ball rolling along a flat plane. You've somehow started it moving at 2 m/s say.
There's really no reason at all it will stop rolling or slow down. Why would it? There's no air resistance in physX and what you "want" it to do in the game engine physics is keep rolling.
Thus what you do is add a script that, essentially, "slows it down a little" every frame. In pseudocode, something like
velocity = 0.99 * velocity
Note however that alternately, to "manually slow it down", you may have to simply add force to it.
The trick is you do that in the opposite direction to movement
yourBalls.addForce( v.normalized * -1 * some small force )
(It's easy to think of that as basically "air resistance")
You usually also, simply, just add a top speed. In this way on downslopes it won't just get "infinitely fast"
if (v.magnitude > 3.0) v = v.normalized * 3.0
That's basically how you make objects roll around on hilly surfaces.
Note that you basically should not fool with the friction settings in anyway, it's really not relevant in most cases.
Unfortunately there is a vast amount of detail but, I feel your question is more asking for the "basic principles" - and there they are!
Tip: it could be this question is more suited to the gameDev site, where "techniques" of game physics are QA'd.

(Unity 3D C#) Conveyor Physics

So, i am trying to create a flat conveyor that a block will sit on and move, but i want to have it be able to turn, so i cant use rigidbody.moveposition, ive tried using addforce, but i cant get it to work properly without using impule or velocity change, because then it makes the ore roll (they are cubes). my most recent attempt was using velocity, but im not sure how to make it keep its old velocity when changing corners so it doesnt screw it up.
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If this doesn't make much sense, here is a better explanation, i am trying to create a conveyor system on a grid, where each slot has a direction, and an cube travels along it, whenever the cube reaches a turn, i want the cube to keep moving forward a short distance so it doesn't just immediately change directions and go along the new conveyor, because this way, it will immediately change and will sit on the edge of the conveyor, and not keep moving in the direction.
edit: i currently have it working, my now issue is the cubes will bounce when touching the conveyor, so they wont stay flat against the conveyor, i can fix this by constricting all the cube rotation, but then it will sometimes freeze the ore on the conveyor, not allowing it to move.
since you didn't provide code, I don't know what you are trying to do, so I will give my own solution:
object.transform.position = Vector3.MoveTowards(target.transform.position, endpoint.position, Time.deltaTime * speed)
Then, when it collides with it, it can turn off this script, so it stays at the end.
target is what you want to move, endpoint is where you want it to end up.
Make endpoint a gameObject, and put it at the end of your conveyor, so the objects will move toward, and it will look like a conveyer.

How to implement trolley-like physics behaviour in Unity

I am stuck with two things while trying to simulate the physics setup for a trolley-like object (push powered vehicle with free rotating wheels on the front and fixed wheels on the back).
I have the RigidBody with its mesh and four WheelColliders, the object moves fine if I just apply torque to the wheels. However if I use the AddForce method on the RigidBody it won't move; I see the object being pushed (slightly balancing) but the wheels won't rotate so it stays in place. How can I get the wheels to move if the object is being pushed?
My other problem is to simulate the standard 360 degrees rotating wheels on the front of the trolley. What would be the best way to simulate this? I was thinking about a horizontal WheelCollider and a vertical one as a child but that seems really weird and I doubt it will actually work. Any ideas?
https://docs.unity3d.com/Manual/WheelColliderTutorial.html
This tutorial shows an example of how to use the wheel colliders and apply steering and torque to them.
It might be what you are looking for in regards to the adding force part.
I suspect it might allow the 360 degree rotation as well, but I am not familiar enough with these colliders to guarantee that.
EDIT:
In the guide there is the line:
public float maxSteeringAngle; // maximum steer angle the wheel can have
Which looks relevant for the 360 degree turning.

How to roll a cube on it's edges on Unity 3D

I want to move a cube by making it roll on it's edges. The cube will be standing on a x-z grid and each movement it takes will make it stand on a different square of the grid.
The player will controll the movement and will only be able to make the cube roll on one direction at a time (left, right, forward or back), but the cube must always stand exactly on top of one of the grid's squares.
I don't think applying a force to the cube will help cause it could move it a little bit too much or too little. I want to achieve something like this: https://www.youtube.com/watch?v=yaAIUYuNi84 but only on the x-z plane. Notice how on each corner the cube can stop and change direction with ease, because it never moves too much or too little.
Any ideas on how to approach this?
If you are new to the Unity it will be useless to trowing you a bunch of codes so i am telling you the way of doing it so you can implement your own codes.
You can create 4 empty game object which will always follow the cube on the floor and when you want to roll the cube you will rotate the cube around the empty objects.
You can find the codes for following the cube and rotating the cube on youtube, and for the starters searching is allways good.
So i hope you can manage it out, if you cant please write me again where did you stuck and i will be happy to answer you :)

How to change the shooting accuracy?

I am making an FPS game using unity 3d, I've a problem in the shooting accuracy script. Can you tell me how I can change it with a single script that shoot the bullet and include the shooting accuracy and equipped to the gun, please?
If you are currently using a raycast, you should have no problem.
If you are spawning a sphere and thrusting it forwards, I suggest you use a raycast.
Raycasts go in a completely straight line. Bullets follow gravity, and quickly fall to the ground.
You don't see bullets, they move too fast. Raycasts are invisible.
When it hits something, it sends you back the information you need. If you make the sphere go too fast, it might glitch through objects.
You can learn about raycasts here.