I don't know if this is the correct therm, but I want to get rid of any kind of forces that could modify the speed of my object. Let me explain : the game is 2D top-down view and the character fires a bullet that bounces x amount of time, WITH CONSTANT SPEED. Everything works fine, but when the bullet bounces fast and many times, its speed increases.
Also, second problem: I have a rotating object and when the bullet hits it, its speed increases (which makes sense, but I would like to know if there is a way to delete this effect) .
I would like to know if there is a way to solve my issues.
You need to check the material of the object for your first question (https://docs.unity3d.com/Manual/class-PhysicMaterial.html) you need to set Bounciness to 1 so it will maintain dame speed. If you set it to 0 there will be no bounce and probably you have a value bigger than 1 and so it's increasing.
In the second case it's all about the forces involving. The object bouncing on the rotating one is adding a force to that one. If you want to keep the second one with same rotation you could rotate it with a transform.Rotate and remove a Rigidbody or set it to static
Related
I have a game similar to Sand balls and I was wondering how can I speed up the game a bit without touching the timescale? A nice and somehow correct approach would be to scale down all my objects so gravity can also "affect" the drop movement. I already tested that and works as expected, except I have to apply that for 100+ levels... and would break some prefabs (a mass level editor to scale by bounding box would work but that's another story)
On the other hand, I have timescale but feels like it's the incorrect approach since it also affects animations and leads to unwanted behaviors.
So... do you know any other ways to speed up the game?
If objects is falling down, you can increase gravity. Or without touching timescale, you can just create a public speed multiplier variable and set it to 1 at start.
If you only move balls (Assumed from give sand balls reference), just multiply speed variable of ball with public speed multiplier variable. When you want to change the speed, just change the variable. As an example:
var ballSpeed = baseBallSpeed * speedMultiplier;
I have been using Unity for a while and still Im not sure about some things, I know there are like 5 different ways to move our character (not using prefabs like for 1st or 3rd person controller I mean just code from scratch) so far for moving a character on a terrain I think setting the speed of the rigidbody works overal for me, just setting the x and leaving the y component as what it was before assigning that, so that gravity effect is kept, overal it works, I manage to collide with wall and other objects, manage to go on terrain and could add jump later in same fashion, but the trouble I find is that my character flies when it steps over any small object like a stone on ground, if he goes over it he starts flying, not a big distance but definetly looks like walking on the moon maybe, also I see that if I have a bridge that is lower in the middle part of it (like U shape) well the character goes like flying from the begining almost until the middle or so, as said works like being on the moon, however gravity seems ok on other objects, I know I can change the gravity value to be higher but Im affraid I could be breaking all that so my question is, is there a better way to move a character on ground that will work better without changing the gravity value? I guess that it can work right without affecting this value, I used other method to change velocity and adding a certain value to the y component but again I see it not right as an apparent correct value for small stones and small objects makes it hard to go over slopes too, any help is greatly welcome =).
I'm going through a few different Unity tutorials and the way a game object is moved around in each is a little different.
What are the pros/cons to each of these methods and which is preferred for a first person RPG?
// Here I use MovePosition function on the rigid body of this component
Rigidbody.MovePosition(m_Rigidbody.position + movement);
//Here I apply force to the rigid body and am able to choose force mode
Rigidbody.AddForce(15 * Time.deltaTime, 0, 0, ForceMode.VelocityChange);
// Here I directly change a transforms position value, in this case the cam
Transform.transform.position = playerTransform.position + cameraOffset;
Thanks!!
EDIT;
Something I have noticed is that the applied force seems to memic wheeled vehicles while the position changes memic walking/running.
RigidBodies and Velocities/Physics
The only time, I personally have used the rigidbodys system was when implementing my own boids (flocking behaviour) as you need to calculate a few separate vectors and apply them all to the unit.
Rigidbody.MovePosition(m_Rigidbody.position + movement);
This calculates a movement vector towards a target for you using the physics system, so the object's velocity and movement can still be affected by drag, angular drag and so on.
This particular function is a wrapper around Rigidbody.AddForce I believe.
Pros :
Good if realistic physical reactions is something you are going for
Cons:
A bit unwieldy to use if all you are trying to achieve is moving a object from point A to point B.
Sometimes an errant setting set too high somewhere (for example: Mass > 10000000) can cause really screwy bugs in behaviour that can be quite a pain to pin down and mitigate.
Notes: Rigidbodies when colliding with another Rigidbody would bounce from each other depending on physics settings.
They are also affected by gravity. Basically they try to mimic real life objects but it can be sometimes difficult to tame the objects and make them do exactly what you want.
And Rigidbody.AddForce is basically the same as above except you calculate the vector yourself.
So for example to get a vector towards a target you would do
Vector3 target = target.position - myPosition;
Rigidbody.AddForce(target * 15 * Time.deltaTime, 0, 0, ForceMode.VelocityChange);
If you don't plan on having any major physics mechanics in your game, I would suggest moving by interpolating the objects position.
As it is far easier to get things to behave how you want, unless of course you are going for physical realism!
Interpolating the units position
Pros :
Perhaps a little strange to understand at first but far simpler to make objects move how you want
Cons:
If you wanted realistic reactions to objects impacting you'd have to do a lot of the work yourself. But sometimes this is preferable to using a physics system then trying, as I've said earlier to tame it.
You would use the technique in say a Pokemon game, you don't stop in Pokemon and wait for ash to stop skidding or hit a wall and bounce uncontrollably backwards.
This particular function is setting the objects position like teleporting but you can also use this to move the character smoothly to a position. I suggest looking up 'tweens' for smoothly interpolating between variables.
//change the characters x by + 1 every tick,
Transform.transform.position.x += 1f;
Rigidbody.MovePosition(m_Rigidbody.position + movement);
From the docs:
If Rigidbody interpolation is enabled on the Rigidbody, calling Rigidbody.MovePosition results in a smooth transition between the two positions in any intermediate frames rendered. This should be used if you want to continuously move a rigidbody in each FixedUpdate.
https://docs.unity3d.com/ScriptReference/Rigidbody.MovePosition.html
Rigidbody.AddForce(15 * Time.deltaTime, 0, 0, ForceMode.VelocityChange);
This will make the object accelerate, so it won't travel at a constant velocity (this is because of Newton's second law, Force=mass*acceleration). Also if you have another force going in the opposite direction this force could get cancelled out and the object won't move at all.
Transform.transform.position = playerTransform.position + cameraOffset;
This will teleport the object. No smooth transition, no interaction with any forces already in the game, just an instant change in position.
I have a cube with Rigidbody attached to it would slide slightly whenever I pressed the play button. If I leave it for awhile, it would slide to other side of the screen.
Anyone know how to solve this problem without using the "freeze position"? I don't know what I messed up in my project...
This is what the object looks like:
Note: I need to use the gravity.
Thank you!
Heh! The solution here is:
You had a rigidbody on the floor :)
You don't do that :) Never.
If the "floor" surface is flat, then,
it will not slide.
You've got something strange going on, such as
"floor" is NOT flat
a feature like "Wind" turned on
perhaps other objects invisible in the scene you have forgotten about are nudging it
PhysX does not have a "mind of it's own". There is some simple reason it is moving.
Let's say the "floor" is indeed on an angle, so it SHOULD move, but you WANT it to NOT move.
What you obviously do:
Just as in the real world, put something there to stop it moving.
A small invisible wall will do the trick. That's PhysX!
Usually rigidbody sliding happens when a lower rigidbody has lower mass than a higher rigidbody (forcing down the lower rigidbody). Typical problem with player having say mass 80 jumping on a cube with mass 1. In this case the collision is so violent that the cube will probably fly out (not only slide).
The situation is very similar to the real world. Try to stay on a box of milk if you have 120 kg (ok, ok, 80 :) ).
When you try to eliminate this behavior, you need either increase the mass of the lower object or decrease the mass of the higher one or set the lower rigidbody to kinematic.
The solutions above is not proper way of solving the problem. Unity has more features of physics than mass. If you get sliding on movement or because of other objects you should add proper drag value on your rigidbody. For example , lets say you have blocks spawning over top of other blocks and this creates horizontal sliding. In my case I add drag of 1 to the objects which has mass of ~ 1 kg. It depends on the scene and you should try different values on your case. Do not use bigger values and angular drag if it is not important.
I have an object that needs to fall down the scene when the game starts. When the player taps the screen the object moves back to the top of the scene. In order to make the object fall I set it to be affected by gravity. This works fine but the problem is the object falls down the screen to fast. Can I set the speed at which the object falls do to gravity to a different speed. If so how do I do this.
You can reduce the gravity of the physicsWorld. Another option is to apply a force in the opposite direction to each object. If the gravity is -9.8 in the y axis, you could apply a force from +0-9.8 in the y axis to slow the object down.
EDIT: Changing the mass does not affect the speed.