How to prevent colliders from passing through each other

Question

I am having trouble keeping game objects inside of a contained space  When they reach the edge  there is some momentary push back but then they will go right through the wall   I am using a Box Collider on the player  and a Mesh Collider for the level s wall  I am having issues with both a Player Character  a space ship  that the movement is controlled by the player  And with projectiles  which are fire and forget moving at a constant speed   This is my movement code for my player  It is being run in the FixedUpdate   function     Movement     haxis   Input GetAxis  Horizontal     speed      vaxis   Input GetAxis  Vertical     speed       moveVector x   haxis      moveVector z   vaxis       if moveVector magnitude  gt  1                moveVector Normalize               rigidbody MovePosition transform position   moveVector   speed     With the bullets  they are given a velocity and the engine calculates their moviements  They are using Box Collider and it is set as a Trigger so they don t have physics  But I use OnTriggerEnter to destroy them     Projectiles without physics collisiions function OnTriggerEnter  other   Collider        Destroy gameObject       Some  but not all of the bullets will be destroyed when hitting the mesh collider wall  The player will sometimes hit it and stop  but can usually push through it   How can I make the collisions with the mesh collider work every time

User · Answer

1   Never use MESH COLLIDER  Use combination of box and capsule collider   2   Check constraints in RigidBody  If you tick Freeze Position X than it will pass through the object on the X axis   Same for y axis

User · Answer

So I haven t been able to get the Mesh Colliders to work  I created a composite collider using simple box colliders and it worked exactly as expected   Other tests with simple Mesh Colliders have come out the same   It looks like the best answer is to build a composite collider out of simple box sphere colliders   For my specific case I wrote a Wizard that creates a Pipe shaped compound collider    script AddComponentMenu  Colliders Pipe Collider    class WizardCreatePipeCollider extends ScriptableWizard       public var outterRadius   float   200      public var innerRadius   float   190      public var sections   int   12      public var height   float   20        MenuItem  GameObject Colliders Create Pipe Collider       static function CreateWizard                 ScriptableWizard DisplayWizard  lt WizardCreatePipeCollider gt   Create Pipe Collider               public function OnWizardUpdate             helpString    Creates a Pipe Collider              public function OnWizardCreate             var theta   float   360f   sections          var width   float   outterRadius - innerRadius           var sectionLength   float   2   outterRadius   Mathf Sin  theta   2    Mathf Deg2Rad            var container   GameObject   new GameObject  Pipe Collider            var section   GameObject          var sectionCollider   GameObject          var boxCollider   BoxCollider           for var i   0  i  lt  sections  i                          section   new GameObject  Section      i   1                 sectionCollider   new GameObject  SectionCollider      i   1                section transform parent   container transform              sectionCollider transform parent   section transform               section transform localPosition   Vector3 zero              section transform localRotation eulerAngles y   i   theta               boxCollider   sectionCollider AddComponent  lt BoxCollider gt                 boxCollider center   Vector3 zero              boxCollider size   new Vector3 width  height  sectionLength                sectionCollider transform localPosition   new Vector3 innerRadius    width   2   0  0

User · Answer

Old Question but maybe it helps someone   Go to Project settings   Time and Try dividing the fixed timestep and maximum allowed timestep by two or by four   I had the problem that my player was able to squeeze through openings smaller than the players collider and that solved it  It also helps with stopping fast moving objects

User · Answer

How about set the Collision Detection of rigidbody to Continuous or Continuous Dynamic   http   unity3d com support documentation Components class-Rigidbody html

User · Answer

I have a pinball prototype that also gave me much trouble in the same areas  These are all the steps I ve taken to almost  but not yet entirely  solve these problems   For fast moving objects    Set the rigidbody s Interpolate to  Interpolate   this does not affect the actual physics simulation  but updates the rendering of the object properly - use this only on important objects from a rendering point of view  like the player  or a pinball  but not for projectiles  Set Collision Detection to Continuous Dynamic Attach the script DontGoThroughThings  https   www auto tuwien ac at wordpress  p 260  to your object  This script cleverly uses the Raycasting solution I posted in my other answer to pull back offending objects to before the collision points    In Edit -  Project Settings -  Physics    Set Min Penetration for Penalty to a very low value  I ve set mine to 0 001 Set Solver Iteration Count to a higher value  I ve set mine to 50  but you can probably do ok with much less    All that is going to have a penalty in performace  but that s unavoidable  The defaults values are soft on performance but are not really intented for proper simulation of small and fast-moving objects

User · Answer

Try setting the models to environment and static  That fix my issue

User · Answer

Collision with fast-moving objects is always a problem  A good way to ensure that you detect all collision is to use Raycasting instead of relying on the physics simulation  This works well for bullets or small objects  but will not produce good results for large objects  http   unity3d com support documentation ScriptReference Physics Raycast html  Pseudo-codeish  I don t have code-completion here and a poor memory    void FixedUpdate         Vector3 direction   new Vector3 transform position - lastPosition       Ray ray   new Ray lastPosition  direction       RaycastHit hit      if  Physics Raycast ray  hit  direction magnitude                    Do something if hit            this lastPosition   transform position

User · Answer

Edit ---  Project Settings ---  Time     decrease  Fixed Timestep  value    This will solve the problem but it can affect performance negatively  Another solution is could be calculate the coordinates  for example  you have a ball and wall  Ball will hit to wall  So calculate coordinates of wall and set hitting process according these cordinates

[unity3d] How to prevent colliders from passing through each other?

Examples related to unity3d

Examples related to game-physics