Still new to game engines and Flame.
I have some tunneling/ghost collision detection using Flame. I found that you should use continuous collision detection(CCD).
I don't see any CCD in Flame or forge2d, what do you do to handel tunneling?
Forge2D has CCD if you set the body to be a bullet with either body.setBullet(true); or bodyDef.bullet = true.
Have you tried the new collision detection system in 1.1.0-releasecandidate.5? It still doesn't do CCD, but it is a bit better than the one in 1.0.0.
Related
I am trying to make some kind of simulation program with Unity. The simulation includes a missile launched from an aircraft and a terrain.
I get the coordinate data required for the movement of the missile from another program using a socket connection.
I created an explosion effect for the missile to explode as soon as the missile and the terrain collided. But the explosion effect is not triggered in any way.
I used the OnCollisionEnter() method to detect the collision, but this method does not seem to work.
The missile has its own rigidbody and collider and The terrain has Terrain Collider, but still no collision is detected and the missile passes through the terrain.
What could be the cause of this error?
EDIT :
I thank everyone for their help, but none of the solutions worked. I solved the error using the OnTriggerEnter method. For this, I also had to enlarge the object's collider a little more.
As mentioned in the comment section above (I dont have enough rep to contribute to the discussion but will provide a solution), you need to enable continuous collision detection. Once you have done that we can move onto the next step.
It is generally bad practice to interact with rigidbodies in update and it can lead to all sorts of strange bugs so I wouldn't recommend it. That being said I dont think it's the cause of your issues. As #HumanWrites mentioned, you are manually moving the position each frame which causes your missile to never actually collide with your mesh. the solution to this is:
rb.MovePosition(Vector3.MoveTowards(...))
The reason for this is that by using the method on the rigidbody, you inform the physics engine that you want to move from one position to the other and you would like the physics to take care of this instead of you doing it directly. This allows it to "sweep" between the current position and target position and detect any collisions that would have happened along the way.
Your missile is moving too fast to ever actually touch the mesh within a frame so you need to rely on the physics engine doing that sweep check.
I am working on a 2D game that involves many blocks that stack and collide on eachother and the player. I am currently using Rigidbody2D on the blocks for dynamic collisions but I am not a fan of how the dynamic physics include the "bounciness" in the elastic collisions. Also, there is an inherent push-force as well as other unfavorable push physics that are too "realistic".
I am wondering what is the best way to handle my predicament to remove the bounciness and push elements of the rigid bodies. I've tried adjusting the block's masses and bounciness physics but no luck. Is there a way to set them all as kinematic or disable these realistic effects somehow and still have them collide via rigidbodies? (Kinematic would be great if they were able to collide with each other) Or will I have to create some sort of raycast based block physics handling script? Or is there an even better solution to creating this very primitive physics structure that I am not seeing?
Thanks for any and all help!
The only way I could think of solving your problem, such that you have complete intuitive accuracy, is to write your own Rigidbody controller. Of course you can still reuse the Box colliders.
Once you've decided on a collision detection method and manifold generation working (raycasting maybe), this link details the impulse resolution you need.
I read that using a physics engine can be the cause of many problems in programming platformer type of games.
I am making something similar to the platformer game(not a classic platformer).
Game will have a platforms, but not many.
Game will not have moving platforms
Game will not have slopes
Game will have ladders
Hero can shoot the enemies
Hero can jump
Hero can access ladders from the air
I have to choose between physics engine and tile tehnique...
The first problems I can think of are:
problem with physics engine and the ladders because physics rules are applied to hero and his movement,so I guess it would be hard to get him on the ladders while his physicsBody.dynamic property is set to YES.
problem with the tile tehnique - how to make hero falling from the ledge(while running) with an realistic arc (when we use physics this is done by engine itself...)?
And the main problem, based on the type of the game I am making, is, sholud I combine tiles tehinque(let's say for hero's moving) and physics engine for collision detection, and shooting enemies?
I know there are a lot of questions about this subject, but I must start from something...
Tnx in advance
I would recommend the physics engine. It is very straight forward... what you expect is generally what happens.
Run, Jump, Shoot, Fall, etc. - Very easy to do using the physics engine.
Ladders will be problematic but you could set a bool flag that lets you know when the ladder and hero are touching, therefore allowing you to exhibit different behaviors depending if this bool is true or not. Ex. Make hero not affected by gravity if touching a ladder.
It is very smart that you are planning this out ahead of time and have outlined all of your core requirements. IMHO, the rest of the requirements will be so easy using the physics engine that it will outweigh additional time spent on the harder part with ladders.
I would advise against using a physics engine unless you have some complex physical interactions that would be difficult to code by hand, i.e. not just collision detection and basic movement but things reacting realistically to collisions, mechanical objects made of many moving parts and joints, etc. I'm not sure what you mean by a "tile technique", but you can easily code by hand things like a character accelerating towards the ground while maintaining forward momentum (i.e. tracing an arc).
i want to detect collision detection two times in same row.
for example:-(see the below image)
the ellipse and rectangle or detcted. after that my ellipse will travelling in the straight line path to down and detect the another rectangle.
first one is( travelled in trajectory path ) working fine. second one i want to pass in straight line to down for collision detection.
how to do this process.
Use the Box2D physics library for collision detection. It is by far the best option in your case and elegantly supported in Cocos2d.
See here: http://www.raywenderlich.com/606/how-to-use-box2d-for-just-collision-detection-with-cocos2d-iphone
As i know cocos2d have no collision detection of sprites because it's not a phys engine. If you want the collision be detected automatically use Box2D or chipmunk physics engine, supported by cocos2d.
If the number of object you want to check for collision is small you can just run over your object and check if some of them (or only one if it's enough for you) overlaps with the others.
Making more complex collision detection will bring you for writing a collision detection part of a physics engine. It's much simpler to use en existing one
What would be the best way to go about adding collision to my application. Right now I have a lot of jagged walls and a couple of weird shapes that I wanna make collision for but am not sure which is the right path to get the job done. What would you guys do if you had a room full of walls with different shapes and sizes that needed collision implemented ?
I would read a set of articles on collision detection. Paul Nettle used to write about the topic (PDF) and has a nice library for free.
This document will describe a
collision technique that allows you to
move an ellipsoid (a sphere with three
different radii, one for each axis)
through a world that not only properly
detects collisions, but also reacts in
a way that gamers would expect from
the common first person shooter.
This technique also allows for sliding
along surfaces as well as easy
implementation of gravity, which
includes sliding downhill when
standing stationary. This technique
also allows automatic climbing of
stairs and sliding over bumps in walls
(like door frames) and any other
randomly oriented “stair-like
topography”.
You can use Chipmunk physics engine, which has a very good physics + collisions.
Or even Cocos2d-iphone library - 2d game engine with Chipmunk inside. Here are examples of games, created with it.