CODEWITHSUNDEEP
iosobjective-csprite-kit
Nielsapp
Nielsapp

Reputation: 302

Spritekit bodyWithbodies does not work

I want my spritenode to have multiple physicbodies. I used bodyWithbodies and added the phyisicbodies. But no collision is detected.

Below the method for creating the spritenode which should have more physicbodies.

-(void)spawnBrick
{
    SKPhysicsBody *brickLeftEdge = [SKPhysicsBody bodyWithEdgeFromPoint:CGPointMake(brick.size.width - brick.size.width, brick.size.height - brick.size.height) toPoint:CGPointMake(brick.size.width - brick.size.width, brick.size.height)];
    brickLeftEdge.categoryBitMask = brickLeftEdgeCategory;
    brickLeftEdge.contactTestBitMask = leftEdgeCategory;

SKPhysicsBody *brickRightEdge = [SKPhysicsBody bodyWithEdgeFromPoint:CGPointMake(brick.size.width, brick.size.height - brick.size.height) toPoint:CGPointMake(brick.size.width, brick.size.height)];
brickRightEdge.categoryBitMask = brickRightEdgeCategory;
brickRightEdge.contactTestBitMask = rightEdgeCategory;

brick = [[BrickNodeOne alloc] init];
brick.name = @"Brick";

NSArray *array = [self objectForKeyedSubscript:@"Brick"];
BrickNodeOne *oldBrick;
if ([array count] > 0) {
    oldBrick = [array objectAtIndex:([array count]-1)];
}
brick.position = CGPointMake(brick.size.width / 2, (brick.size.height + oldBrick.position.y)-15);
brick.physicsBody = [SKPhysicsBody bodyWithBodies:@[brickLeftEdge, brickRightEdge]];

    brick.physicsBody.collisionBitMask = 0;
    [self addChild:brick];
}

In DidMoveToView I declared the left and right edge of the screen for collision detection with the spritenode

    // setup edges
_leftEdge = [[SKNode alloc] init];
// heigt + 1000 = for spawned objects above screen
_leftEdge.physicsBody = [SKPhysicsBody bodyWithEdgeFromPoint:CGPointMake(0.0, 0.0) toPoint:CGPointMake(0.0, self.size.height + 1000)];
_leftEdge.physicsBody.dynamic = NO;
_leftEdge.physicsBody.categoryBitMask = leftEdgeCategory;
_leftEdge.physicsBody.contactTestBitMask = brickLeftEdgeCategory;
_leftEdge.position = CGPointZero;
[self addChild:_leftEdge];

_rightEdge = [[SKNode alloc] init];
// heigt + 1000 = for spawned objects above screen
_rightEdge.physicsBody = [SKPhysicsBody bodyWithEdgeFromPoint:CGPointMake(self.size.width, 0.0) toPoint:CGPointMake(self.size.width, self.size.height + 1000)];
_rightEdge.physicsBody.dynamic = NO;
_rightEdge.physicsBody.categoryBitMask = rightEdgeCategory;
_rightEdge.physicsBody.contactTestBitMask = brickRightEdgeCategory;
[self addChild:_rightEdge];

The following code contains the bitmask information:

I declared SKPhysicsContactDelegate in the header file. Set the delegate in didMoveToView

static const uint32_t leftEdgeCategory          = 0x1 << 0;
static const uint32_t rightEdgeCategory         = 0x1 << 1;
static const uint32_t brickLeftEdgeCategory     = 0x1 << 2;
static const uint32_t brickRightEdgeCategory    = 0x1 << 3;
static const uint32_t kCarCategory              = 0x1 << 4;

Information for comment

So I changed the physicsbody from edge to rectangle, unfortunately no contact was detected. 

SKPhysicsBody *brickLeftEdge = [SKPhysicsBody bodyWithRectangleOfSize:CGSizeMake(40, brick.size.height) center:CGPointMake((brick.size.width - brick.size.width) + 20 , self.size.height / 2)];
brickLeftEdge.categoryBitMask = brickLeftEdgeCategory;
brickLeftEdge.contactTestBitMask = leftEdgeCategory;

SKPhysicsBody *brickRightEdge = [SKPhysicsBody bodyWithRectangleOfSize:CGSizeMake(40, brick.size.height) center:CGPointMake(brick.size.width - 20, brick.size.height / 2)];
brickRightEdge.categoryBitMask = brickRightEdgeCategory;
brickRightEdge.contactTestBitMask = rightEdgeCategory;

Upvotes: 1

Views: 110

Answers (1)

Whirlwind
Whirlwind

Reputation: 13665

The problem you have is related to the fact that you are using static physics bodies. This is from the docs about bodyWithEdgeFromPoint: toPoint method:

An edge has no volume or mass and is always treated as if the dynamic property is equal to NO. Edges may only collide with volume-based physics bodies.

Means, collisions can happen only when at least one body is defined as dynamic (volume-based physics bodies are dynamic by default).

Upvotes: 1

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