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Scene Kit Session WWDC 2014/Sources/Slides/AAPLSlideParticles.m

#import "AAPLPresentationViewController.h"

#import "AAPLSlideTextManager.h"

#import "AAPLSlide.h"

#import "Utils.h"

typedef enum {

    Step0,

    StepFire,

    StepFireScreen,

//    StepFireSubtract,

    StepLocal,

    StepGravity,

    StepCollider,

    StepFields,

    StepFieldsVortex,

    StepSubSystems,

    StepConfetti,

    StepEmitterCube,

    StepEmitterSphere,

    StepEmitterTorus,

    StepCount

} ParticleSteps;

@interface AAPLSlideParticles : AAPLSlide

    SCNNode *_hole;

    SCNNode *_hole2;

    SCNNode *_floorNode;

    SCNNode *_boxNode;

    SCNNode *_particleHolder;

    SCNNode *_fieldOwner;

    SCNNode *_vortexFieldOwner;

    SCNParticleSystem *_snow;

    SCNParticleSystem *_bokeh;

@end

SCNVector3 SCNVector3CrossProduct(const SCNVector3 a, const SCNVector3 b){

    //  return a.yzx * b.zxy - a.zxy * b.yzx;

    SCNVector3 out;

    out.x = a.y*b.z - a.z*b.y;

    out.y = a.z*b.x - a.x*b.z;

    out.z = a.x*b.y - a.y*b.x;

    return out;

CGFloat SCNVector3Length(const SCNVector3 a){

    return (CGFloat) (sqrt (a.x * a.x + a.y * a.y + a.z * a.z));

SCNVector3 SCNVector3Normalize(const SCNVector3 a){

    CGFloat invlen = 1.0 / SCNVector3Length(a);

    SCNVector3 out;

    out.x = a.x * invlen;

    out.y = a.y * invlen;

    out.z = a.z * invlen;

    return out;

@implementation AAPLSlideParticles

- (void)setupSlideWithPresentationViewController:(AAPLPresentationViewController *)presentationViewController {

    // Set the slide's title and add some text

    self.textManager.title = @"Particles";

    self.textManager.subtitle = @"SCNParticleSystem";

    [self.textManager addBullet:@"Achieve a large number of effects" atLevel:0];

    [self.textManager addBullet:@"3D particle editor built into Xcode" atLevel:0];

/*

 -> emitter shape

 fire/reactor  -> color ramp

 smoke -> local/global

 etincelles -> gravity + colliders

 rain -> subsystem

 snow -> fields

 bokeh  (multiple images)

 xcode editor

// explosions

*/

- (NSUInteger) numberOfSteps

    return StepCount;

static inline SCNVector3 __cross(SCNVector3 a, SCNVector3 b)

    SCNVector3 c;

    c.x = a.y*b.z - a.z*b.y;

    c.y = a.z*b.x - a.x*b.z;

    c.z = a.x*b.y - a.y*b.x;

    return c;

- (void)presentStepIndex:(NSUInteger)index withPresentationViewController:(AAPLPresentationViewController *)presentationViewController

#define HOLE_Z 10

    switch(index)

        case StepFire:

            [self.textManager flipOutTextOfType:AAPLTextTypeBullet];

            [self.textManager addEmptyLine];

            [self.textManager addBullet:@"Particle image" atLevel:0];

            [self.textManager addBullet:@"Color over life duration" atLevel:0];

            [self.textManager addBullet:@"Size over life duration" atLevel:0];

            [self.textManager addBullet:@"Several blend modes" atLevel:0];

            [self.textManager flipInTextOfType:AAPLTextTypeBullet];

            SCNNode *hole = [SCNNode node];

            hole.geometry = [SCNTube tubeWithInnerRadius:1.7 outerRadius:1.9 height:1.5];

            hole.position = SCNVector3Make(0, 0, HOLE_Z);

            hole.scale = SCNVector3Make(1, 0, 1);

            [self.groundNode addChildNode:hole];

            [SCNTransaction begin];

            [SCNTransaction setAnimationDuration:0.5];

            hole.scale = SCNVector3Make(1,1,1);

            [SCNTransaction commit];

            SCNParticleSystem *ps = [SCNParticleSystem particleSystemNamed:@"fire" inDirectory:nil];

            [hole addParticleSystem:ps];

            _hole = hole;

            break;

        case StepFireScreen:

            SCNParticleSystem *ps = [[_hole particleSystems] firstObject];

            ps.blendMode = SCNParticleBlendModeScreen;

        } break;

/*

        case StepFireSubtract:

            NSColor *col = [NSColor colorWithCalibratedWhite:0.7 alpha:1.0];

            [CATransaction begin];

            [CATransaction setAnimationDuration:5.5];

            presentationViewController.presentationView.backgroundColor = col;

            [CATransaction commit];

            [SCNTransaction begin];

            [SCNTransaction setAnimationDuration:5.5];

            presentationViewController.presentationView.scene.fogColor = col;

            [SCNTransaction commit];

            SCNParticleSystem *ps = [[_hole particleSystems] firstObject];

            ps.blackPassEnabled = NO;

            ps.blendMode = SCNParticleBlendModeSubtract;

        } break;

*/

        case StepLocal:

            [self.textManager flipOutTextOfType:AAPLTextTypeBullet];

            [self.textManager addBullet:@"Local or global" atLevel:0];

            [self.textManager flipInTextOfType:AAPLTextTypeBullet];

            [_hole removeAllParticleSystems];

            _hole2 = [_hole clone];

            _hole2.geometry = [_hole.geometry copy];

            _hole2.position = SCNVector3Make(0, -2, HOLE_Z-4);

            [self.groundNode addChildNode:_hole2];

            [SCNTransaction begin];

            [SCNTransaction setAnimationDuration:0.5];

            _hole2.position = SCNVector3Make(0, 0, HOLE_Z-4);

            [SCNTransaction commit];

            SCNParticleSystem *ps = [SCNParticleSystem particleSystemNamed:@"smoke" inDirectory:nil];

            ps.particleColorVariation = SCNVector4Make(0, 0, 0.5, 0);

            [_hole addParticleSystem:ps];

            SCNParticleSystem *localPs = [ps copy];

            localPs.particleImage = ps.particleImage; // FIXME: remove when <rdar://problem/16957114> ParticleSystems does not copy its image

            localPs.local = YES;

            [_hole2 addParticleSystem:localPs];

                CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"position"];

                animation.fromValue = [NSValue valueWithSCNVector3:SCNVector3Make(7, 0, HOLE_Z)];

                animation.toValue = [NSValue valueWithSCNVector3:SCNVector3Make(-7, 0, HOLE_Z)];

                animation.beginTime = CACurrentMediaTime() + 0.75;

                animation.duration = 8;

                animation.autoreverses = YES;

                animation.repeatCount = MAXFLOAT;

                animation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];

                animation.timeOffset = animation.duration/2;

                [_hole addAnimation:animation forKey:@"animateHole"];

                CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"position"];

                animation.fromValue = [NSValue valueWithSCNVector3:SCNVector3Make(-7, 0, HOLE_Z-4)];

                animation.toValue = [NSValue valueWithSCNVector3:SCNVector3Make(7, 0, HOLE_Z-4)];

                animation.beginTime = CACurrentMediaTime() + 0.75;

                animation.duration = 8;

                animation.autoreverses = YES;

                animation.repeatCount = MAXFLOAT;

                animation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];

                animation.timeOffset = animation.duration/2;

                [_hole2 addAnimation:animation forKey:@"animateHole"];

            break;

        case StepGravity:

            [self.textManager flipOutTextOfType:AAPLTextTypeBullet];

            [self.textManager addBullet:@"Affected by gravity" atLevel:0];

            [self.textManager flipInTextOfType:AAPLTextTypeBullet];

            [_hole2 removeAllParticleSystems];

            [_hole2 runAction:[SCNAction sequence:@[[SCNAction scaleTo:0 duration:0.5], [SCNAction removeFromParentNode]]]];

            [_hole removeAllParticleSystems];

            [_hole removeAnimationForKey:@"animateHole" fadeOutDuration:0.5];

            [SCNTransaction begin];

            [SCNTransaction setAnimationDuration:0.5];

            SCNTube *tube = (SCNTube*) _hole.geometry;

            tube.innerRadius = 0.3;

            tube.outerRadius = 0.4;

            tube.height = 1.0;

            [SCNTransaction commit];

            SCNParticleSystem *ps = [SCNParticleSystem particleSystemNamed:@"sparks" inDirectory:nil];

            [_hole removeAllParticleSystems];

            [_hole addParticleSystem:ps];

            _floorNode = [presentationViewController.presentationView.scene.rootNode childNodesPassingTest:^BOOL(SCNNode *child, BOOL *stop) {

                return [child.geometry isKindOfClass:[SCNFloor class]];

            }][0];

            ps.colliderNodes = @[_floorNode];

            break;

        case StepCollider:

            [self.textManager flipOutTextOfType:AAPLTextTypeBullet];

            [self.textManager addBullet:@"Affected by colliders" atLevel:0];

            [self.textManager flipInTextOfType:AAPLTextTypeBullet];

            SCNNode *boxNode = [SCNNode node];

            boxNode.geometry = [SCNBox boxWithWidth:5 height:0.2 length:5 chamferRadius:0];

            boxNode.position = SCNVector3Make(0, 7, HOLE_Z);

            boxNode.geometry.firstMaterial.emission.contents = [NSColor darkGrayColor];

            [self.groundNode addChildNode:boxNode];

            SCNParticleSystem*ps = [_hole particleSystems][0];

            ps.colliderNodes = @[_floorNode, boxNode];

            CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"eulerAngles"];

            animation.fromValue = [NSValue valueWithSCNVector3:SCNVector3Make(0, 0, M_PI_4*1.7)];

            animation.toValue = [NSValue valueWithSCNVector3:SCNVector3Make(0, 0, -M_PI_4*1.7)];

            animation.beginTime = CACurrentMediaTime() + 0.5;

            animation.duration = 2;

            animation.autoreverses = YES;

            animation.repeatCount = MAXFLOAT;

            animation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];

            animation.timeOffset = animation.duration/2;

            [boxNode addAnimation:animation forKey:@"animateHole"];

            _boxNode = boxNode;

            break;

        case StepFields:

            [_hole removeAllParticleSystems];

            [_hole runAction:[SCNAction sequence:@[[SCNAction scaleTo:0 duration:0.75], [SCNAction removeFromParentNode]]]];

            [_boxNode runAction:[SCNAction sequence:@[[SCNAction moveByX:0 y:15 z:0 duration:1.0], [SCNAction removeFromParentNode]]]];

            SCNNode *particleHolder = [SCNNode node];

            particleHolder.position = SCNVector3Make(0, 20, HOLE_Z);

            [self.groundNode addChildNode:particleHolder];

            _particleHolder = particleHolder;

            [self.textManager flipOutTextOfType:AAPLTextTypeBullet];

            [self.textManager addBullet:@"Affected by physics fields" atLevel:0];

            [self.textManager flipInTextOfType:AAPLTextTypeBullet];

            SCNParticleSystem *ps = [SCNParticleSystem particleSystemNamed:@"snow" inDirectory:nil];

            ps.affectedByPhysicsFields = YES;

            [_particleHolder addParticleSystem:ps];

            _snow = ps;

            //physics field

            SCNPhysicsField *field = [SCNPhysicsField turbulenceFieldWithSmoothness:50 animationSpeed:1];

            field.halfExtent = SCNVector3Make(20, 20, 20);

            field.strength = 4.0;

            SCNNode *fieldOwner = [SCNNode node];

            fieldOwner.position = SCNVector3Make(0, 5, HOLE_Z);

            [self.groundNode addChildNode:fieldOwner];

            fieldOwner.physicsField = field;

            _fieldOwner = fieldOwner;

            ps.colliderNodes = @[_floorNode];

            break;

        case StepFieldsVortex:

            _vortexFieldOwner = [SCNNode node];

            _vortexFieldOwner.position = SCNVector3Make(0, 5, HOLE_Z);

            [self.groundNode addChildNode:_vortexFieldOwner];

            //tornado

            __block SCNVector3 _worldOrigin = SCNVector3Make(_fieldOwner.worldTransform.m41,_fieldOwner.worldTransform.m42,_fieldOwner.worldTransform.m43);

            __block SCNVector3 _worldAxis = (SCNVector3) {0,1,0};

#define VS 20.0

#define VW 10.0

            SCNPhysicsField *vortex = [SCNPhysicsField customFieldWithEvaluationBlock:^SCNVector3(SCNVector3 position, SCNVector3 velocity, float mass, float charge, NSTimeInterval time) {

                SCNVector3 l;

                l.x = _worldOrigin.x - position.x;

                l.z = _worldOrigin.z - position.z;

                SCNVector3 t = __cross(_worldAxis, l);

                float d2 = (l.x*l.x + l.z*l.z);

                float vs = VS / sqrt(d2);

                float fy = 1.0 - (MIN(1.0,(position.y/ 15.0)));

                return SCNVector3Make(t.x * vs + l.x * VW * fy, 0, t.z * vs + l.z * VW * fy);

}];

            vortex.halfExtent = SCNVector3Make(100, 100, 100);

            _vortexFieldOwner.physicsField = vortex;

            break;

        case StepSubSystems:

            [_fieldOwner removeFromParentNode];

            [_particleHolder removeAllParticleSystems];

            _snow.dampingFactor = -1;

            [self.textManager flipOutTextOfType:AAPLTextTypeBullet];

            [self.textManager addBullet:@"Sub-particle system on collision" atLevel:0];

            [self.textManager flipInTextOfType:AAPLTextTypeBullet];

            SCNParticleSystem *ps = [SCNParticleSystem particleSystemNamed:@"rain" inDirectory:nil];

            SCNParticleSystem *pss = [SCNParticleSystem particleSystemNamed:@"plok" inDirectory:nil];

            pss.idleDuration = 0;

            pss.loops = NO;

            [ps setSystemSpawnedOnCollision:pss];

            [_particleHolder addParticleSystem:ps];

            ps.colliderNodes = @[_floorNode];

            break;

        case StepConfetti:

            [_particleHolder removeAllParticleSystems];

            [self.textManager flipOutTextOfType:AAPLTextTypeBullet];

            [self.textManager addBullet:@"Custom blocks" atLevel:0];

            [self.textManager flipInTextOfType:AAPLTextTypeBullet];

                SCNParticleSystem *ps = [SCNParticleSystem particleSystem];

                ps.emitterShape = [SCNBox boxWithWidth:20 height:0 length:5 chamferRadius:0];

                ps.birthRate = 100;

                ps.particleLifeSpan = 5;

                ps.particleLifeSpanVariation = 0;

                ps.spreadingAngle = 20;

                ps.particleSize = 0.25;

                ps.particleVelocity = 5;

                ps.particleVelocityVariation = 2;

                ps.birthDirection = SCNParticleBirthDirectionConstant;

                ps.emittingDirection = SCNVector3Make(0, -1, 0);

                ps.birthLocation = SCNParticleBirthLocationVolume;

                ps.particleImage = @"confetti.png";

                ps.lightingEnabled = YES;

                ps.orientationMode = SCNParticleOrientationModeFree;

                ps.sortingMode = SCNParticleSortingModeDistance;

                ps.particleAngleVariation = 180;

                ps.particleAngularVelocity = 200;

                ps.particleAngularVelocityVariation = 400;

                ps.particleColor = [NSColor greenColor];

                ps.particleColorVariation = SCNVector4Make(0.2, 0.1, 0.1, 0);

                ps.particleBounce = 0;

                ps.particleFriction = 0.6;

                ps.colliderNodes = @[_floorNode];

                ps.blendMode = SCNParticleBlendModeAlpha;

                CAKeyframeAnimation *floatAnimation = [CAKeyframeAnimation animationWithKeyPath:nil];

                floatAnimation.values = @[@1, @1, @0];

                floatAnimation.keyTimes = @[@0, @0.9, @1];

                floatAnimation.duration = 1.0;

                floatAnimation.additive = NO;

                ps.propertyControllers = @{ SCNParticlePropertyOpacity: [SCNParticlePropertyController controllerWithAnimation:floatAnimation] };

                [ps handleEvent:SCNParticleEventBirth forProperties:@[SCNParticlePropertyColor] withBlock:^(void **data, size_t *dataStride, uint32_t *indices , NSInteger count) {

                    for (NSInteger i = 0; i < count; ++i) {

                        float *col = (float *)((char *)data[0] + dataStride[0] * i);

                        if (rand() & 0x1) { // swith green for red

                            col[0] = col[1];

                            col[1] = 0;

}];

                [ps handleEvent:SCNParticleEventCollision forProperties:@[SCNParticlePropertyAngle, SCNParticlePropertyRotationAxis, SCNParticlePropertyAngularVelocity, SCNParticlePropertyVelocity, SCNParticlePropertyContactNormal] withBlock:^(void **data, size_t *dataStride, uint32_t *indices , NSInteger count) {

                    for (NSInteger i = 0; i < count; ++i) {

                        // fix orientation

                        float *angle = (float *)((char *)data[0] + dataStride[0] * indices[i]);

                        float *axis = (float *)((char *)data[1] + dataStride[1] * indices[i]);

                        float *colNrm = (float *)((char *)data[4] + dataStride[4] * indices[i]);

                        SCNVector3 collisionNormal = {colNrm[0], colNrm[1], colNrm[2]};

                        SCNVector3 cp = SCNVector3CrossProduct(collisionNormal, SCNVector3Make(0, 0, 1));

                        CGFloat cpLen = SCNVector3Length(cp);

                        angle[0] = asin(cpLen);

                        axis[0] = cp.x / cpLen;

                        axis[1] = cp.y / cpLen;

                        axis[2] = cp.z / cpLen;

                        // kill angular rotation

                        float *angVel = (float *)((char *)data[2] + dataStride[2] * indices[i]);

                        angVel[0] = 0;

                        if (colNrm[1] > 0.4) {

                            float *vel = (float *)((char *)data[3] + dataStride[3] * indices[i]);

                            vel[0] = 0;

                            vel[1] = 0;

                            vel[2] = 0;

}];

                [_particleHolder addParticleSystem:ps];

                _particleHolder.position = SCNVector3Make(0, 15, HOLE_Z);

            break;

        case StepEmitterCube:

            [_particleHolder removeAllParticleSystems];

            [self.textManager flipOutTextOfType:AAPLTextTypeBullet];

            [self.textManager addBullet:@"Emitter shape" atLevel:0];

            [self.textManager flipInTextOfType:AAPLTextTypeBullet];

            [_particleHolder removeFromParentNode];

            SCNParticleSystem *ps = [SCNParticleSystem particleSystemNamed:@"emitters" inDirectory:nil];

            ps.local = YES;

            [_particleHolder addParticleSystem:ps];

            SCNNode *node = [SCNNode node];

            node.position = SCNVector3Make(3, 6, HOLE_Z);

            [node runAction:[SCNAction repeatActionForever:[SCNAction rotateByAngle:M_PI * 2 aroundAxis:SCNVector3Make(0.3, 1, 0) duration:8]]];

            [self.groundNode addChildNode:node];

            _bokeh = ps;

            [node addParticleSystem:ps];

            break;

        case StepEmitterSphere:

            _bokeh.emitterShape = [SCNSphere sphereWithRadius:5];

            break;

        case StepEmitterTorus:

            _bokeh.emitterShape = [SCNTorus torusWithRingRadius:5 pipeRadius:1];

            break;

- (void)willOrderOutWithPresentationViewController:(AAPLPresentationViewController *)presentationViewController {

    [presentationViewController.presentationView.scene removeAllParticleSystems];

@end

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