Creating a Body - Cocos2d/Box2d - iphone

I have a ball and another sprite. When the ball collides with the sprite it simulates falling.
My only problem is the other sprite is just on big image and the ball is on top of it, but there are spaces on the sprite and a lot of corners. I need to determine if the sprite has touch one of the corners. I know this is hard to understand.
So, my question is, is it possible to make a body without
b2PolygonShape blockShape;
and
blockShapeDef.shape = &blockShape;
OR
is there an alternative I can use? I cannot set the image as a box and it would take way to long to set edges because there are so many corners.
I have already set up the collision detection.
I really need help with this.
Thanks!


If you want it to react properly, you have to make a polygon using every single corner coordinate.
But don't be lazy about it. You can use SpriteHelper for creating *b2PolygonShape*s out of your sprites.
Or another alternative: VertexHelper

Related

Can you paint a tile on sprite overlap? Unity

Hi all I'm trying to make a game where I can drive around and as I pass over certain tiles in my tile-map they change colour, dead simple problem in my head. However not sure how to change the painted tile on overlap, my thinking was I could use sprite collision detection but when I put my sprites on the same z-axis height they overlay and are no longer visible. Is there something I have missed or a more efficient way of going about this?
Thanks :)

Detect collisons only on the border of a collider,How to detect collisions only on the border of a collider but not inside?

I am creating a 2D game and I want to implement two game objects with circular colliders to detect collisions following say an object is travelling from Point A to Point B then -
See the image for details
Thanks for the help

I think the easiest answer is to just make a polygon collider 2D that looks like a ring, like so but without the gap and much thinner:
Then you can use OnTriggerStay2D to run the code you'd like to run on collision.

Masking and Physics in SpriteKit

When using SKCropNode in SpriteKit, does the masking affect the physics of the node? (e.g. I crop half of the sprite, will a ball fall through the masked part of the image?) If this is the case, how would I go about creating the SKCropNode so it would crop where ever I touch?
Cheers

SKCropNode only pertains to how a node appears on the screen, it does not deal with physics bodies. You can however use SKPhysicsBody(polygonFrom:CGPath) to create a path that is identical to the body you are trying to mimic, with the gap and everything. I recommend using the program PhysicsEditor to achieve such effect. https://www.codeandweb.com/physicseditor

Adding Collision Detection to SKTileMapNode

What's the recommended way of adding collision detection to an SKTileMapNode for a side scroller?
Say I have a simple tilemap with just one single tile to use as the ground, how can I detect when my player sprite lands on one of the filled ground tiles?

I'm not entirely sure this will work, but it seems you could add a node to each of a SKTileMapNode's tiles and, based on whatever texture component is on it, give it a physics body appropriately shaped and setup for matching that texture.
Here is someone attempting something like this:
https://forums.developer.apple.com/thread/50043
You don't ask for it, but for greater granularity (eg a tile that's partially covered and needs a sloping physics floor element), it seems this would be the place to start:
https://developer.apple.com/reference/spritekit/sktiledefinition
But I can't find exactly how to know what part of a texture is on any given tile of a tile-map. There must be a way to do this, but I'm just not quite seeing it.

Cocos2d - Creating collidable Sprites?

Hello everyone I an very new to cocos2d, so I apologize if this is a simple question. I would like to create to sprites that collide when they hit each other.
For instance, one sprite, spriteA, is in a fixed position on the screen. And another sprite, spriteB, is moving around the screen. SpriteB will collide with spriteA. If that doesn't make sense or you don't understand it, tell me and I will elaborate further. Any help is appreciated. Thank YOU!

Try using Chipmunk or Box2d physics systems. These are included with Cocos2d and work by having a physics simulation that updates with every time the graphics change on screen.
The physics simulation will tell you if two objects are overlapping, and will provide physical attributes like weight, slipperiness (friction), speed and direction, which creates reactions like bouncing, sliding, realistic loss of speed and changes of direction on impact.
If you are new to physics simulation, here's a 30 second run down:
Create "bodies" in the physics simulation that represent each graphical sprite
Bodies are usually defined more simply than their graphical counterparts, like a circle, square or simple polygon shape
In order to update the graphics on the screen accurately, first you establish a pixels to meters ratio. Meters are notional (i.e. made up) measurement that is used in the physics sim
Each time the physics simulation "ticks", you update the graphics on screen accordingly
So if a body in the physics sim moves 1 meter, you might transform the pixel sprite 32 pixels
Here's a good tute on collision detection using Box2d.
http://www.raywenderlich.com/606/how-to-use-box2d-for-just-collision-detection-with-cocos2d-iphone
enjoy

Its actually very simple:
Just schedule a timer: [self schedule:#selector(checkForCollision:)];
Specify the method: - (void)checkForCollision:(ccTime)dt {}
In the curly braces, make CGRects for each sprite using CGRectMake.
Then in the same method, just call: if (CGRectIntersectsRect) {}
That easy!

Well technically speaking when the 2 sprites interact, or share at least one common point, then they are colliding. I'm a little confused by your question. Are you asking for direction on how to make the sprite move on screen, or are you asking how to handle the actual collision(such as calling a method if they collide)?