SpriteKit's SKPhysicsBody with polygon helper tool
Asked Answered
S

8

21

I wonder if there is a tool that could be used for easy generation of complex physics bodies in SpriteKit. I would like to have a volume based physical bodies with polygon-type shapes. SpriteKit allows to create such bodies with that method:

+ (SKPhysicsBody *)bodyWithPolygonFromPath:(CGPathRef)path

Unfortunately it's time consuming task to generate such paths manually, and it could be problematic when testing. There is a SpriteHelper application that allows you to define body shape within easy-to-use visual editor, but this app can't export paths that could be used here. It was made for cocos2d and it does a lot of things like texture packing etc. that I don't need and I can't use with SpriteKit. Does anyone know a solution that will allow to define CGPath's easily or maybe even auto-generate them from png images with alpha channel? Although auto-generation feature from my experience would need optimization, because the body shapes should be as simple as possible when textures could have more complicated shapes.

Seedling answered 26/9, 2013 at 23:6 Comment(5)
PhysicsEditor will get a Sprite Kit update soon.Licko
@LearnCocos2D I will definitely buy it when SpriteKit support would be added. I hope there will be option to export collision shapes in Objective-c code format (CGPath declaration or something similar). Exporting to a custom file format read by external library is not what I'm looking for.Seedling
code export is a really bad idea because it breaks easily, good tools always write to a custom file format (typically as xml) and then provide loader codeLicko
What I am looking for is a solution to this one problem. I really don't need anything else to be exported, only the CGPath that describes physic shape. XML format for export is good choice, but only if there won't be any extra data in it. Parsing that XML in runtime should be simple and quick to process. I don't know how current version of PhysicsEditor works, but what I definitely don't like in SpriteHelper is that only way to export physic shapes is to generate huge file with all informations about texture atlas, sprites positions etc.Seedling
See: adriancooney.ie/SKImport/EditorFrier
R
68

I am looking for the exact same thing, as it turn out I have done a small web app for this purpose.

SKPhysicsBody Path Generator

as action in example: enter image description here

Update 2015-02-13: script

<!DOCTYPE html>
<html>
    <head>
        <meta charset="UTF-8">
        <title>SpriteKit Tools - SKPhysicsBody Path Generator</title>
        <link rel="stylesheet" href="//netdna.bootstrapcdn.com/bootstrap/3.0.0/css/bootstrap.min.css">

        <style>
            /* disable responsive */
            .container {
                max-width: none;
                width: 970px;
            }
            #sprite {
                background-color: #eee;
                position: absolute;
            }
            #path {
                cursor: crosshair;
                opacity: 0.5;
            }
        </style>

    </head>
    <body>
        <div class="container">
            <h1>SKPhysicsBody Path Generator</h1>
            <p class="lead">Want to use [SKPhysicsBody bodyWithPolygonFromPath:path] easier way like me? Here with a small helper for easier path drawing, hope it help others too.</p>
            <div class="row">
                <div class="col-md-6">
                    <h5>Basic Instruction</h5>
                    <ol>
                        <li><small>Drag and drop the sprite image into drop zone.</small></li>
                        <li><small>Start drawing path by clicking on coordinates.</small></li>
                    </ol>
                </div>
                <div class="col-md-6">
                    <h5>Some Rules / Known Issue</h5>
                    <ul>
                        <li><small>Path need to be as a convex polygonal path with counterclockwise winding and no self intersections. The points are specified relative to the owning node’s origin. <a href="https://developer.apple.com/documentation/spritekit/skphysicsbody/1520379-bodywithpolygonfrompath" target="_blank">(documentation link)</a></small></li>
                        <li><small>Please use Chrome for best compatibility as I have not tested on other browsers.</small></li>
                    </ul>
                </div>
            </div>


            <hr>

            <div class="btn-group">
                <button class="btn btn-primary" type="button" onclick="resetShape()">Reset Shape</button>
                <button class="btn btn-primary" type="button" onclick="location.reload()">Reset All</button>
            </div>
            <input type="checkbox" onclick="toggleRetinaMode()" id="retinaCheckbox" checked> Retina? (please check before declaring path)
            <br><br>

            <canvas id="sprite" width="940" height="100"></canvas>
            <canvas id="path" width="0" height="100"></canvas>

            <p class="text-muted"><small>X:<span id="tooltipX">0</span> Y:<span id="tooltipY">0</span></small></p>
            <br>

            <h5>Output</h5>
<pre>
SKSpriteNode *sprite = [SKSpriteNode spriteNodeWithImageNamed:@"<span id="codeImgName">img</span>"];

CGFloat offsetX = sprite.frame.size.width * sprite.anchorPoint.x;
CGFloat offsetY = sprite.frame.size.height * sprite.anchorPoint.y;

CGMutablePathRef path = CGPathCreateMutable();

<span id="codeCGPath"></span>
CGPathCloseSubpath(path);

sprite.physicsBody = [SKPhysicsBody bodyWithPolygonFromPath:path];
</pre>

        </div>

        <script>
// reference from http://davidwalsh.name/resize-image-canvas

var spriteCanvas = document.getElementById('sprite');
var spriteContext = spriteCanvas.getContext('2d');
spriteContext.fillText('Drop Sprite Image Here', 400, 50);

var pathCanvas = document.getElementById('path');
var pathContext = pathCanvas.getContext('2d');

function render(src){
    var image = new Image();
    image.onload = function(){
        spriteContext.clearRect(0, 0, spriteCanvas.width, spriteCanvas.height);
        spriteCanvas.width = image.width;
        spriteCanvas.height = image.height;
        spriteContext.drawImage(image, 0, 0, image.width, image.height);

        pathContext.clearRect(0, 0, pathCanvas.width, pathCanvas.height);
        pathCanvas.width = image.width;
        pathCanvas.height = image.height;
    };
    image.src = src;
}

function loadImage(src){

    if(!src.type.match(/image.*/)){
        console.log('Dropped file is not image format');
        return;
    }

    var reader = new FileReader();
    reader.onload = function(e){
        render(e.target.result);
    };
    reader.readAsDataURL(src);

    var fileName = src.name;
    var codeImgName = document.getElementById('codeImgName');
    codeImgName.innerHTML = fileName;
}

spriteCanvas.addEventListener('dragover', function(e){
    e.preventDefault();
}, true);

spriteCanvas.addEventListener('drop', function(e){
    e.preventDefault();
    loadImage(e.dataTransfer.files[0]);
}, true);


var retinaMode = true;
function toggleRetinaMode(){
    var status = document.getElementById('retinaCheckbox');

    retinaMode = status.checked ? true : false;
}



var actualX = 0;
var actualY = 0;
var displayX = document.getElementById('tooltipX');
var displayY = document.getElementById('tooltipY');

pathCanvas.onmousemove = function(e){
    actualX = e.pageX - this.offsetLeft;
    actualY = e.pageY - this.offsetTop;
    displayX.innerHTML = retinaMode ? Math.floor(actualX / 2) : actualX;
    displayY.innerHTML = retinaMode ? Math.floor((spriteCanvas.height - actualY - 1) / 2) : spriteCanvas.height - actualY - 1;
}

var pathArray = new Array();
pathCanvas.onclick = function(e){
    var coor = {
        actualX: actualX,
        actualY: actualY,
        displayX: displayX.innerHTML,
        displayY: displayY.innerHTML,
    };
    pathArray.push(coor);
    refreshShape(pathArray);
}

var codeCGPath = document.getElementById('codeCGPath');
function refreshShape(pathArray){

    pathContext.clearRect(0, 0, pathCanvas.width, pathCanvas.height);

    pathContext.beginPath();

    for(var i in pathArray){
        if(i == 0) {
            pathContext.moveTo(pathArray[i].actualX, pathArray[i].actualY);
            codeCGPath.innerHTML = 'CGPathMoveToPoint(path, NULL, '+pathArray[i].displayX+' - offsetX, '+pathArray[i].displayY+' - offsetY);<br>';
            continue;
        }
        pathContext.lineTo(pathArray[i].actualX, pathArray[i].actualY);
        codeCGPath.innerHTML += 'CGPathAddLineToPoint(path, NULL, '+pathArray[i].displayX+' - offsetX, '+pathArray[i].displayY+' - offsetY);<br>';
    }

    pathContext.closePath();
    pathContext.lineWidth = 1;
    pathContext.strokeStyle = 'blue';
    pathContext.stroke();
    pathContext.fillStyle = 'blue';
    pathContext.fill();
}

function resetShape(){
    pathArray = new Array();
    codeCGPath.innerHTML = null;
    pathContext.clearRect(0, 0, pathCanvas.width, pathCanvas.height);
}
        </script>
    </body>
</html>
Renfrow answered 1/10, 2013 at 3:15 Comment(9)
Yeah! This is exactly what I was looking for! I think many people agree that what you made is worth further development. I there any place I could write feature requests?Seedling
@Seedling , yeah. Just leave it in comment section below. I am aware of some features while coding it but I temporary leave the complicated stuff to be fill in future and get the basic up and run for the time being (because I'm on a game development progress right now). Anyway, I will encourage you to leave in the comment section and others may read before posting same thing over. :)Renfrow
This is one of the most helpful things I have seen. Great work.Ablation
I'm tempted to make bogus SO accounts just so I can upvote this more... Fantastic job @DazChong!!Gasometer
Very nice! Works great and saves a ton of time!Telegraphone
Great tool! Works perfectlyOlden
Sir cant thank you enough. I am on journey to make my first game and this tool helped a lot. Do you have any github repo for this.Lordinwaiting
Can you make the question work with a certain scale value. When I have to use the setScale function to scale a sprite to how I like it. The Path doesn't seem to scale with it.Determiner
@Renfrow anyway you can update this for Swift 3.0? CGPathMoveToPoint is now move(to: transform) #39508887Rectify
K
10

I created an editor and loader class to create complex SKPhysicsBodies and import them into your code. It allows you to trace around your sprite, add multiple bodies and export all within a pretty nice interface. Check out the SKImport here and the editor.

Screencast

Kila answered 26/5, 2014 at 22:27 Comment(0)
O
6

I know this is a bit late, but I've just created a cool tool for this purpose which automatically creates a path around the sprite image (so you don't have to manually click on the points yourself), and then you can adjust various settings to better suit your requirements. The tool also outputs both Objective C and Swift program code for adding the path to a sprite physics body. Hope it's helpful to some people. Thanks:

http://www.radicalphase.com/pathgen/

Organza answered 26/4, 2015 at 18:55 Comment(3)
too bad...link is deadFelker
sorry the domain name expired - tool is back again now though! :)Organza
New Update: Now includes a force convex mode (enabled by default) to ensure 100% compatibility with SpriteKit Physics Bodies, and also to reduce the points count - enjoy! :)Organza
C
4

Here is the original script (from DazChong) adapted for Swift

SKPhysicsBody Path Generator Swift Version

<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <title>SpriteKit Tools - SKPhysicsBody Path Generator (Swift version </title>
    <link rel="stylesheet" href="//netdna.bootstrapcdn.com/bootstrap/3.0.0/css/bootstrap.min.css">

    <style>
        /* disable responsive */
        .container {
            max-width: none;
            width: 970px;
        }

            #sprite {
                background-color: #eee;
                position: absolute;
            }
            #path {
                cursor: crosshair;
                opacity: 0.5;
            }
        </style>

    </head>
    <body>
        <div class="container">
            <h1>SKPhysicsBody Path Generator</h1>
            <p class="lead">Want to use SKPhysicsBody(polygonFromPath: path) easier way like me? Here with a small helper for easier path drawing, hope it help others too.</p>
            <div class="row">
                <div class="col-md-6">
                    <h5>Basic Instruction</h5>
                    <ol>
                        <li><small>Drag and drop the sprite image into drop zone.</small></li>
                        <li><small>Start drawing path by clicking on coordinates.</small></li>
                    </ol>
                </div>
                <div class="col-md-6">
                    <h5>Some Rules / Known Issue</h5>
                    <ul>
                        <li><small>Path need to be as a convex polygonal path with counterclockwise winding and no self intersections. The points are specified relative to the owning node’s origin. <a href="https://developer.apple.com/library/ios/documentation/SpriteKit/Reference/SKPhysicsBody_Ref/Reference/Reference.html#//apple_ref/occ/clm/SKPhysicsBody/bodyWithPolygonFromPath:" target="_blank">(documentation link)</a></small></li>
                        <li><small>Please use Chrome for best compatibility as I have not tested on other browsers.</small></li>
                    </ul>
                </div>
            </div>


            <hr>

            <div class="btn-group">
                <button class="btn btn-primary" type="button" onclick="resetShape()">Reset Shape</button>
                <button class="btn btn-primary" type="button" onclick="location.reload()">Reset All</button>
            </div>
            <input type="checkbox" onclick="toggleRetinaMode()" id="retinaCheckbox" checked> Retina? (please check before declaring path)
            <br><br>

            <canvas id="sprite" width="940" height="100"></canvas>
            <canvas id="path" width="0" height="100"></canvas>

            <p class="text-muted"><small>X:<span id="tooltipX">0</span> Y:<span id="tooltipY">0</span></small></p>
            <br>

            <h5>Output</h5>
<pre>
let sprite = SKSpriteNode(imageNamed: "codeImgName")

let offsetX = sprite.size.width * sprite.anchorPoint.x
let offsetY = sprite.size.height * sprite.anchorPoint.y

let path = CGPathCreateMutable()

<span id="codeCGPath"></span>
CGPathCloseSubpath(path)

sprite.physicsBody = SKPhysicsBody(polygonFromPath: path)
</pre>

        </div>

        <script>
// reference from http://davidwalsh.name/resize-image-canvas

var spriteCanvas = document.getElementById('sprite');
var spriteContext = spriteCanvas.getContext('2d');
spriteContext.fillText('Drop Sprite Image Here', 400, 50);

var pathCanvas = document.getElementById('path');
var pathContext = pathCanvas.getContext('2d');

function render(src){
    var image = new Image();
    image.onload = function(){
        spriteContext.clearRect(0, 0, spriteCanvas.width, spriteCanvas.height);
        spriteCanvas.width = image.width;
        spriteCanvas.height = image.height;
        spriteContext.drawImage(image, 0, 0, image.width, image.height);

        pathContext.clearRect(0, 0, pathCanvas.width, pathCanvas.height);
        pathCanvas.width = image.width;
        pathCanvas.height = image.height;
    };
    image.src = src;
}

function loadImage(src){

    if(!src.type.match(/image.*/)){
        console.log('Dropped file is not image format');
        return;
    }

    var reader = new FileReader();
    reader.onload = function(e){
        render(e.target.result);
    };
    reader.readAsDataURL(src);

    var fileName = src.name;
    var codeImgName = document.getElementById('codeImgName');
    codeImgName.innerHTML = fileName;
}

spriteCanvas.addEventListener('dragover', function(e){
    e.preventDefault();
}, true);

spriteCanvas.addEventListener('drop', function(e){
    e.preventDefault();
    loadImage(e.dataTransfer.files[0]);
}, true);


var retinaMode = true;
function toggleRetinaMode(){
    var status = document.getElementById('retinaCheckbox');

    retinaMode = status.checked ? true : false;
}



var actualX = 0;
var actualY = 0;
var displayX = document.getElementById('tooltipX');
var displayY = document.getElementById('tooltipY');

pathCanvas.onmousemove = function(e){
    actualX = e.pageX - this.offsetLeft;
    actualY = e.pageY - this.offsetTop;
    displayX.innerHTML = retinaMode ? Math.floor(actualX / 2) : actualX;
    displayY.innerHTML = retinaMode ? Math.floor((spriteCanvas.height - actualY - 1) / 2) : spriteCanvas.height - actualY - 1;
}

var pathArray = new Array();
pathCanvas.onclick = function(e){
    var coor = {
        actualX: actualX,
        actualY: actualY,
        displayX: displayX.innerHTML,
        displayY: displayY.innerHTML,
    };
    pathArray.push(coor);
    refreshShape(pathArray);
}

var codeCGPath = document.getElementById('codeCGPath');
function refreshShape(pathArray){

    pathContext.clearRect(0, 0, pathCanvas.width, pathCanvas.height);

    pathContext.beginPath();

    for(var i in pathArray){
        if(i == 0) {
            pathContext.moveTo(pathArray[i].actualX, pathArray[i].actualY);
            codeCGPath.innerHTML = 'CGPathMoveToPoint(path, nil, '+pathArray[i].displayX+' - offsetX, '+pathArray[i].displayY+' - offsetY)<br>';
            continue;
        }
        pathContext.lineTo(pathArray[i].actualX, pathArray[i].actualY);
        codeCGPath.innerHTML += 'CGPathAddLineToPoint(path, nil, '+pathArray[i].displayX+' - offsetX, '+pathArray[i].displayY+' - offsetY)<br>';
    }

    pathContext.closePath();
    pathContext.lineWidth = 1;
    pathContext.strokeStyle = 'blue';
    pathContext.stroke();
    pathContext.fillStyle = 'blue';
    pathContext.fill();
}

function resetShape(){
    pathArray = new Array();
    codeCGPath.innerHTML = null;
    pathContext.clearRect(0, 0, pathCanvas.width, pathCanvas.height);
}
        </script>
    </body>
</html>
Calendar answered 28/7, 2015 at 15:34 Comment(0)
W
2

The Skphysicsbody Path generator tool seems to be missing. I wrote an app that does the same thing though on mac: https://itunes.apple.com/us/app/physicsbodymaker/id951249779?ls=1&mt=12

Works answered 20/12, 2014 at 22:51 Comment(0)
A
2

This is an adaptation of Xelt's answer in Swift 3.

<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <title>SpriteKit Tools - SKPhysicsBody Path Generator (Swift version </title>
    <link rel="stylesheet" href="//netdna.bootstrapcdn.com/bootstrap/3.0.0/css/bootstrap.min.css">

    <style>
        /* disable responsive */
        .container {
            max-width: none;
            width: 970px;
        }

            #sprite {
                background-color: #eee;
                position: absolute;
            }
            #path {
                cursor: crosshair;
                opacity: 0.5;
            }
        </style>

    </head>
    <body>
        <div class="container">
            <h1>SKPhysicsBody Path Generator</h1>
            <p class="lead">Want to use SKPhysicsBody(polygonFromPath: path) easier way like me? Here with a small helper for easier path drawing, hope it help others too.</p>
            <div class="row">
                <div class="col-md-6">
                    <h5>Basic Instruction</h5>
                    <ol>
                        <li><small>Drag and drop the sprite image into drop zone.</small></li>
                        <li><small>Start drawing path by clicking on coordinates.</small></li>
                    </ol>
                </div>
                <div class="col-md-6">
                    <h5>Some Rules / Known Issue</h5>
                    <ul>
                        <li><small>Path need to be as a convex polygonal path with counterclockwise winding and no self intersections. The points are specified relative to the owning node’s origin. <a href="https://developer.apple.com/library/ios/documentation/SpriteKit/Reference/SKPhysicsBody_Ref/Reference/Reference.html#//apple_ref/occ/clm/SKPhysicsBody/bodyWithPolygonFromPath:" target="_blank">(documentation link)</a></small></li>
                        <li><small>Please use Chrome for best compatibility as I have not tested on other browsers.</small></li>
                    </ul>
                </div>
            </div>


            <hr>

            <div class="btn-group">
                <button class="btn btn-primary" type="button" onclick="resetShape()">Reset Shape</button>
                <button class="btn btn-primary" type="button" onclick="location.reload()">Reset All</button>
            </div>
            <input type="checkbox" onclick="toggleRetinaMode()" id="retinaCheckbox" checked> Retina? (please check before declaring path)
            <br><br>

            <canvas id="sprite" width="940" height="100"></canvas>
            <canvas id="path" width="0" height="100"></canvas>

            <p class="text-muted"><small>X:<span id="tooltipX">0</span> Y:<span id="tooltipY">0</span></small></p>
            <br>

            <h5>Output</h5>
<pre>
let sprite = SKSpriteNode(imageNamed: "codeImgName")

let offsetX = sprite.size.width * sprite.anchorPoint.x
let offsetY = sprite.size.height * sprite.anchorPoint.y

let path = CGMutablePath()

<span id="codeCGPath"></span>
path.closeSubpath()

sprite.physicsBody = SKPhysicsBody(polygonFromPath: path)
</pre>

        </div>

        <script>
// reference from http://davidwalsh.name/resize-image-canvas

var spriteCanvas = document.getElementById('sprite');
var spriteContext = spriteCanvas.getContext('2d');
spriteContext.fillText('Drop Sprite Image Here', 400, 50);

var pathCanvas = document.getElementById('path');
var pathContext = pathCanvas.getContext('2d');

function render(src){
    var image = new Image();
    image.onload = function(){
        spriteContext.clearRect(0, 0, spriteCanvas.width, spriteCanvas.height);
        spriteCanvas.width = image.width;
        spriteCanvas.height = image.height;
        spriteContext.drawImage(image, 0, 0, image.width, image.height);

        pathContext.clearRect(0, 0, pathCanvas.width, pathCanvas.height);
        pathCanvas.width = image.width;
        pathCanvas.height = image.height;
    };
    image.src = src;
}

function loadImage(src){

    if(!src.type.match(/image.*/)){
        console.log('Dropped file is not image format');
        return;
    }

    var reader = new FileReader();
    reader.onload = function(e){
        render(e.target.result);
    };
    reader.readAsDataURL(src);

    var fileName = src.name;
    var codeImgName = document.getElementById('codeImgName');
    codeImgName.innerHTML = fileName;
}

spriteCanvas.addEventListener('dragover', function(e){
    e.preventDefault();
}, true);

spriteCanvas.addEventListener('drop', function(e){
    e.preventDefault();
    loadImage(e.dataTransfer.files[0]);
}, true);


var retinaMode = true;
function toggleRetinaMode(){
    var status = document.getElementById('retinaCheckbox');

    retinaMode = status.checked ? true : false;
}



var actualX = 0;
var actualY = 0;
var displayX = document.getElementById('tooltipX');
var displayY = document.getElementById('tooltipY');

pathCanvas.onmousemove = function(e){
    actualX = e.pageX - this.offsetLeft;
    actualY = e.pageY - this.offsetTop;
    displayX.innerHTML = retinaMode ? Math.floor(actualX / 2) : actualX;
    displayY.innerHTML = retinaMode ? Math.floor((spriteCanvas.height - actualY - 1) / 2) : spriteCanvas.height - actualY - 1;
}

var pathArray = new Array();
pathCanvas.onclick = function(e){
    var coor = {
        actualX: actualX,
        actualY: actualY,
        displayX: displayX.innerHTML,
        displayY: displayY.innerHTML,
    };
    pathArray.push(coor);
    refreshShape(pathArray);
}

var codeCGPath = document.getElementById('codeCGPath');
function refreshShape(pathArray){

    pathContext.clearRect(0, 0, pathCanvas.width, pathCanvas.height);

    pathContext.beginPath();

    for(var i in pathArray){
        if(i == 0) {
            pathContext.moveTo(pathArray[i].actualX, pathArray[i].actualY);
            codeCGPath.innerHTML = 'path.move(to: CGPoint(x:  '+pathArray[i].displayX+' - offsetX, y: '+pathArray[i].displayY+' - offsetY))<br>';
            continue;
        }
        pathContext.lineTo(pathArray[i].actualX, pathArray[i].actualY);
        codeCGPath.innerHTML += 'path.addLine(to: CGPoint(x: '+pathArray[i].displayX+' - offsetX, y: '+pathArray[i].displayY+' - offsetY))<br>';
    }

    pathContext.closePath();
    pathContext.lineWidth = 1;
    pathContext.strokeStyle = 'blue';
    pathContext.stroke();
    pathContext.fillStyle = 'blue';
    pathContext.fill();
}

function resetShape(){
    pathArray = new Array();
    codeCGPath.innerHTML = null;
    pathContext.clearRect(0, 0, pathCanvas.width, pathCanvas.height);
}
        </script>
    </body>
</html>
Aftergrowth answered 25/11, 2016 at 0:5 Comment(0)
H
1

Awesome little web app, by DazChong. And canot wait for the update of PhysicsEditor!!

This one is also in development

You can download it in alpha stage here

enter image description here

Hygrophilous answered 4/10, 2013 at 22:56 Comment(3)
This is awesome! Thanks for sharing. Maybe the app title shall include 'SpriteKit' for easier searches landing.Renfrow
@Renfrow yeah has great potential. I like your web app, shame SpriteKit only allows 12 points for a path. If you dont know, there is also this but $$$$ paintcodeapp.comHygrophilous
the problem with the 12 points for path is even worst than that because it has to be basically 12 points joined by straight lines. I have tried to use shapes that had 12 points but were using bezier curves between then and received a message like "using more than 300 points" or whatever gigantic number like that. Apple did a lame job with this and btw, SpriteKit is a bag of bugs: I have reported at least 20 bugs I have discovered in a week using it.Kush
S
0

You can just do this now to generate physics body from your sprite's PNG:

SKSpriteNode *yourPhysicsSprite = [SKSpriteNode spriteNodeWithImageNamed:@"yourPNG"];
yourPhysicsSprite.physicsBody = [SKPhysicsBody bodyWithTexture:yourPhysicsSprite.texture alphaThreshold:0.0f size:yourPhysicsSprite.texture.size];

Less precise and perhaps more costly than doing by hand, but works fine.

Spelaean answered 29/9, 2015 at 3:34 Comment(3)
It wasn't possible in SpriteKit when I asked the question. Now it's possible, but not very efficient.Seedling
Is it possible to do this polygon-from-path generation from inside XCode now? If so, where is it? I am stil having troubles with this.Roentgenoscope
Just so people know, there is a huge bug in iOS9 that prevents you from using textures to make accurate physics bodies. Strangely it worked in iOS8 and works in iOS10 but massive issues in iOS9, still not fixed as of today (all though there are some not great workarounds).Uncharitable

© 2022 - 2024 — McMap. All rights reserved.