I'm currently trying to develop an arkanoid-like game in Unity but I'm having a problem that I can't seem to be able to solve with a satisfying solution.
When the ball hits the edges of two adjacent bricks, it "reflects" the velocity in an unexpected way: the ball goes to the direction where it was coming from.
For information, I have a world space size of : 5.625x, and each brick has a size of 0.703125 for 8 bricks per line. Also, every bricks have the same Y size for the collider.
I tried increasing the x size of the collider to some reasonable extent (0.74x for example) to make sure there's no gap between two bricks but the problem still occurs sometimes.
Here is a very ugly picture illustrating what's happening (the green arrow being the expected trajectory):
Thanks in advance for your help!
EDIT: Here are the inspector informations regarding the ball and the bricks. Regarding the lines of bricks, it's basically eight game objects with a boxcollider2d and a kinematic rigidbody2d.
The ball material has a friction of 0 and a bounciness of 1.
Related
This bug occurs very rarely (probably 1 in 100 collisions with a platform) where the players box collider 2d have contacts with the platform horizontally (two contacts with (-1,0) vectors and two (intented) with(0,1)). This is very problematic because the player cannot jump forward (just jumps up without any x velocity) and it looks like it hits an invisible wall. I tried increasing the default contact offset in the physics 2D settings to 0.01 but it did not help. I am creating a pixel art game with 16 Pixels per unit.
After researching I finally found a fix for my problem. My problem was that the player got stuck inbetween my tiles each having a boxcollider with the TilemapCollider2D. I fixed it by removing each collider to one whole with a composite:
add TilemapCollider2D to the tile layer's component
check "used by composite" field in TilemapCollider2D
set Rigidbody2D to static
I had to check composite collider to polygons because otherwise I could not apply any Force to the rigidbody somehow.
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'm casting SphereCastAll in direction of the red line and I sometimes have a strange issue that this cast misses some colliders like in the screen below. The green line shows SphereCastAll origin and closest hit with different rigidbody to not collides with own colliders. SphereCastAll radius is half of car width.
Sometimes SphereCastAll misses all colliders from car in front and hits the next car.
Rigidbody is moving by WheelColliders
Here's a link
One interesting aspect of Physics.SphereCast() is that it occasionally fails if the sphere was already colliding with an object. Thus for Physics.SphereCastAll() it might not return the first (couple of) collisions if the sphere would already be colliding with them. Consider using Physics.OverlapSphere() to get the collisions you are missing or reducing the radius of the SphereCast to such a radius where the SphereCast cannot start inside of any other enemies / cars / what-have-you.
I've got a ray cast being created from the 'yellow X' in the pictures below. It is detecting the collision hit, however the distance is way off (~ 21 instead of 7 etc) . The green X shows where the collision is taking place and hence how long the distance should be
The Line Renderer is being drawn from start point along the forward vector for the ray hit distance, so in the second picture you can see where I have a much smaller plane with better tessellation it works fine, but with a larger ground plane in the first picture it is way off. It also works fine with other objects in the scene like small boxes.
I have tried using a box collider which still has the same problem.
Any ideas?
I'm creating a fast-paced, 2D side-scrolling game on Unity 5.2, building my terrain out of discrete "blocks", each with its own EdgeCollider2D component.
Having a problem where my character gets bumped upward as it crosses from one block to another (imagine driving your car over a speed bump on the road).
This doesn't happen all the time. Seems to be random, which is even more irritating, as it makes finding a solution more difficult.
I've tried all of the suggestions that I could find for similar questions on this site, including:
Using CircleCollider2D's on the character
making sure the terrain blocks and their corresponding colliders are perfectly aligned. The attached screenshot shows one of the intersections.
changing the "Min penetration for penalty" setting to the minimum allowed value (0.0001)
switching between discrete and continuous collision detection for the character's RigidBody2D
increasing the mass and gravity scale for the character's RigidBody2D
... to no avail.
Beyond building a single, massive terrain object with a single edge collider from start to finish (which I'm trying to avoid), I've run out of ideas. Anything else I'm missing? Is it just a Unity bug?
Help!
Try detect the collision and set the vertical velocity to zero.
void OnCollisionEnter2D(Collision2D col)
{
if (col.gameObject.name.StartsWith("block"))
rigidbody2d.velocity = new Vector2(rigidbody2d.velocity.x, 0);
}