From cc515062f34e6167e8518e7df01392734d4d9160 Mon Sep 17 00:00:00 2001
From: "zhefeng.zhang" <35944775+zhefengzhang@users.noreply.github.com>
Date: Tue, 16 Sep 2025 16:40:04 +0800
Subject: [PATCH 1/3] fixed when low fps cannot play particle

---
 cocos/particle/particle-system.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/cocos/particle/particle-system.ts b/cocos/particle/particle-system.ts
index 7ac6b9a652a..a9b125535b0 100644
--- a/cocos/particle/particle-system.ts
+++ b/cocos/particle/particle-system.ts
@@ -1443,7 +1443,7 @@ export class ParticleSystem extends ModelRenderer {
         // emit particles.
         const startDelay = self.startDelay.evaluate(0, 1)!;
         if (self._time > startDelay) {
-            if (self._time > (self.duration + startDelay)) {
+            if (self._time - (self.duration + startDelay) > dt) {
                 // self._time = startDelay; // delay will not be applied from the second loop.(Unity)
                 // self._emitRateTimeCounter = 0.0;
                 // self._emitRateDistanceCounter = 0.0;

From 9316e67673648d51f4692183e0157e3e8ed51037 Mon Sep 17 00:00:00 2001
From: "zhefeng.zhang" <35944775+zhefengzhang@users.noreply.github.com>
Date: Mon, 27 Oct 2025 16:49:09 +0800
Subject: [PATCH 2/3] Update particle-system.ts

---
 cocos/particle/particle-system.ts | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/cocos/particle/particle-system.ts b/cocos/particle/particle-system.ts
index a9b125535b0..661533d7a14 100644
--- a/cocos/particle/particle-system.ts
+++ b/cocos/particle/particle-system.ts
@@ -1443,7 +1443,8 @@ export class ParticleSystem extends ModelRenderer {
         // emit particles.
         const startDelay = self.startDelay.evaluate(0, 1)!;
         if (self._time > startDelay) {
-            if (self._time - (self.duration + startDelay) > dt) {
+            const timeLeft = self._time - (self.duration + startDelay);
+            if (timeLeft > dt) {
                 // self._time = startDelay; // delay will not be applied from the second loop.(Unity)
                 // self._emitRateTimeCounter = 0.0;
                 // self._emitRateDistanceCounter = 0.0;
@@ -1478,8 +1479,10 @@ export class ParticleSystem extends ModelRenderer {
             }
 
             // bursts
-            for (const burst of self.bursts) {
-                burst.update(self, dt);
+            if (timeLeft <= 0) {
+                for (const burst of self.bursts) {
+                    burst.update(self, dt);
+                }
             }
         }
     }

From bb7009aa7d5ed2e2a07d58e1162af7a9550402b2 Mon Sep 17 00:00:00 2001
From: "zhefeng.zhang" <35944775+zhefengzhang@users.noreply.github.com>
Date: Tue, 28 Oct 2025 12:17:52 +0800
Subject: [PATCH 3/3] Update particle-system.ts

---
 cocos/particle/particle-system.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/cocos/particle/particle-system.ts b/cocos/particle/particle-system.ts
index 661533d7a14..18469e5f76e 100644
--- a/cocos/particle/particle-system.ts
+++ b/cocos/particle/particle-system.ts
@@ -1479,7 +1479,7 @@ export class ParticleSystem extends ModelRenderer {
             }
 
             // bursts
-            if (timeLeft <= 0) {
+            if (timeLeft <= 0 || self.loop) {
                 for (const burst of self.bursts) {
                     burst.update(self, dt);
                 }