diff --git a/leenkx/Sources/iron/object/ParticleSystem.hx b/leenkx/Sources/iron/object/ParticleSystem.hx
index 5c94f08..ca9fef5 100644
--- a/leenkx/Sources/iron/object/ParticleSystem.hx
+++ b/leenkx/Sources/iron/object/ParticleSystem.hx
@@ -2,6 +2,7 @@ package iron.object;
 
 #if lnx_particles
 
+import kha.FastFloat;
 import kha.graphics4.Usage;
 import kha.arrays.Float32Array;
 import iron.data.Data;
@@ -16,39 +17,45 @@ import iron.math.Vec4;
 class ParticleSystem {
 	public var data: ParticleData;
 	public var speed = 1.0;
+	var currentSpeed = 0.0;
 	var particles: Array<Particle>;
 	var ready: Bool;
-	public var frameRate = 24;
-	public var lifetime = 0.0;
-	public var animtime = 0.0;
-	public var time = 0.0;
-	public var spawnRate = 0.0;
+	var frameRate = 24;
+	var lifetime = 0.0;
+	var animtime = 0.0;
+	var time = 0.0;
+	var spawnRate = 0.0;
+	var looptime = 0.0;
 	var seed = 0;
 
-	public var r: TParticleData;
-	public var gx: Float;
-	public var gy: Float;
-	public var gz: Float;
-	public var alignx: Float;
-	public var aligny: Float;
-	public var alignz: Float;
+	var r: TParticleData;
+	var gx: Float;
+	var gy: Float;
+	var gz: Float;
+	var alignx: Float;
+	var aligny: Float;
+	var alignz: Float;
 	var dimx: Float;
 	var dimy: Float;
 	var tilesx: Int;
 	var tilesy: Int;
 	var tilesFramerate: Int;
 
-	public var count = 0;
-	public var lap = 0;
-	public var lapTime = 0.0;
+	var count = 0;
+	var lap = 0;
+	var lapTime = 0.0;
 	var m = Mat4.identity();
 
 	var ownerLoc = new Vec4();
 	var ownerRot = new Quat();
 	var ownerScl = new Vec4();
+	
+	var random = 0.0;
 
 	public function new(sceneName: String, pref: TParticleReference) {
 		seed = pref.seed;
+		currentSpeed = speed;
+		speed = 0;
 		particles = [];
 		ready = false;
 		
@@ -65,34 +72,61 @@ class ParticleSystem {
 				gy = 0;
 				gz = -9.81 * r.weight_gravity;
 			}
-			alignx = r.object_align_factor[0] / 2;
-			aligny = r.object_align_factor[1] / 2;
-			alignz = r.object_align_factor[2] / 2;
+			alignx = r.object_align_factor[0];
+			aligny = r.object_align_factor[1];
+			alignz = r.object_align_factor[2];
+			looptime = (r.frame_end - r.frame_start) / frameRate;
 			lifetime = r.lifetime / frameRate;
-			animtime = (r.frame_end - r.frame_start) / frameRate;
+			animtime = r.loop ? looptime : looptime + lifetime;
 			spawnRate = ((r.frame_end - r.frame_start) / r.count) / frameRate;
 
 			for (i in 0...r.count) {
-				var particle = new Particle(i);
-				particle.sr = 1 - Math.random() * r.size_random;
-				particles.push(particle);
+				particles.push(new Particle(i));
 			}
 
 			ready = true;
+			if (r.auto_start){
+				start();
+			}
 		});
 	}
 
+	public function start() {
+		if (r.is_unique) random = Math.random();
+		lifetime = r.lifetime / frameRate;
+		time = 0;
+		lap = 0;
+		lapTime = 0;
+		speed = currentSpeed;
+	}
+
 	public function pause() {
-		lifetime = 0;
+		speed = 0;
 	}
 
 	public function resume() {
 		lifetime = r.lifetime / frameRate;
+		speed = currentSpeed;
 	}
 
+
+
+	// TODO: interrupt smoothly
+	public function stop() {
+		end();
+	}
+
+	function end() {
+		lifetime = 0;
+		speed = 0;
+		lap = 0;
+	}
+	
 	public function update(object: MeshObject, owner: MeshObject) {
 		if (!ready || object == null || speed == 0.0) return;
 
+		var prevLap = lap;
+
 		// Copy owner world transform but discard scale
 		owner.transform.world.decompose(ownerLoc, ownerRot, ownerScl);
 		object.transform.loc = ownerLoc;
@@ -115,17 +149,21 @@ class ParticleSystem {
 		}
 
 		// Animate
-		time += Time.delta * speed;
+		time += Time.renderDelta * speed;
 		lap = Std.int(time / animtime);
 		lapTime = time - lap * animtime;
 		count = Std.int(lapTime / spawnRate);
 
+		if (lap > prevLap && !r.loop) {
+			end();
+		}
+		
 		updateGpu(object, owner);
 	}
 
 	public function getData(): Mat4 {
 		var hair = r.type == 1;
-		m._00 = r.loop ? animtime : -animtime;
+		m._00 = animtime;
 		m._01 = hair ? 1 / particles.length : spawnRate;
 		m._02 = hair ? 1 : lifetime;
 		m._03 = particles.length;
@@ -133,9 +171,9 @@ class ParticleSystem {
 		m._11 = hair ? 0 : aligny;
 		m._12 = hair ? 0 : alignz;
 		m._13 = hair ? 0 : r.factor_random;
-		m._20 = hair ? 0 : gx * r.mass;
-		m._21 = hair ? 0 : gy * r.mass;
-		m._22 = hair ? 0 : gz * r.mass;
+		m._20 = hair ? 0 : gx;
+		m._21 = hair ? 0 : gy;
+		m._22 = hair ? 0 : gz;
 		m._23 = hair ? 0 : r.lifetime_random;
 		m._30 = tilesx;
 		m._31 = tilesy;
@@ -144,13 +182,25 @@ class ParticleSystem {
 		return m;
 	}
 
+	public function getSizeRandom(): FastFloat {
+		return r.size_random;
+	}
+
+	public function getRandom(): FastFloat {
+		return random;
+	}
+
+	public function getSize(): FastFloat {
+		return r.particle_size;
+	}
+
 	function updateGpu(object: MeshObject, owner: MeshObject) {
 		if (!object.data.geom.instanced) setupGeomGpu(object, owner);
 		// GPU particles transform is attached to owner object
 	}
 
-	public function setupGeomGpu(object: MeshObject, owner: MeshObject) {
-		var instancedData = new Float32Array(particles.length * 6);
+	function setupGeomGpu(object: MeshObject, owner: MeshObject) {
+		var instancedData = new Float32Array(particles.length * 3);
 		var i = 0;
 
 		var normFactor = 1 / 32767; // pa.values are not normalized
@@ -169,10 +219,6 @@ class ParticleSystem {
 					instancedData.set(i, pa.values[j * pa.size    ] * normFactor * scaleFactor.x); i++;
 					instancedData.set(i, pa.values[j * pa.size + 1] * normFactor * scaleFactor.y); i++;
 					instancedData.set(i, pa.values[j * pa.size + 2] * normFactor * scaleFactor.z); i++;
-
-					instancedData.set(i, p.sr); i++;
-					instancedData.set(i, p.sr); i++;
-					instancedData.set(i, p.sr); i++;
 				}
 
 			case 1: // Face
@@ -196,10 +242,6 @@ class ParticleSystem {
 					instancedData.set(i, pos.x * normFactor * scaleFactor.x); i++;
 					instancedData.set(i, pos.y * normFactor * scaleFactor.y); i++;
 					instancedData.set(i, pos.z * normFactor * scaleFactor.z); i++;
-
-					instancedData.set(i, p.sr); i++;
-					instancedData.set(i, p.sr); i++;
-					instancedData.set(i, p.sr); i++;
 				}
 
 			case 2: // Volume
@@ -210,13 +252,9 @@ class ParticleSystem {
 					instancedData.set(i, (Math.random() * 2.0 - 1.0) * scaleFactorVolume.x); i++;
 					instancedData.set(i, (Math.random() * 2.0 - 1.0) * scaleFactorVolume.y); i++;
 					instancedData.set(i, (Math.random() * 2.0 - 1.0) * scaleFactorVolume.z); i++;
-
-					instancedData.set(i, p.sr); i++;
-					instancedData.set(i, p.sr); i++;
-					instancedData.set(i, p.sr); i++;
 				}
 		}
-		object.data.geom.setupInstanced(instancedData, 3, Usage.StaticUsage);
+		object.data.geom.setupInstanced(instancedData, 1, Usage.StaticUsage);
 	}
 
 	function fhash(n: Int): Float {
@@ -255,10 +293,11 @@ class ParticleSystem {
 
 class Particle {
 	public var i: Int;
-	public var px = 0.0;
-	public var py = 0.0;
-	public var pz = 0.0;
-	public var sr = 1.0; // Size random
+	
+	public var x = 0.0;
+	public var y = 0.0;
+	public var z = 0.0;
+
 	public var cameraDistance: Float;
 
 	public function new(i: Int) {