diff --git a/.gitignore b/.gitignore
index 9c56d08..178eef5 100644
--- a/.gitignore
+++ b/.gitignore
@@ -24,3 +24,5 @@ ui_*.h
 /paysages3d-linux.tar.bz2
 /config.vim
 /callgrind.out.*
+*.p3d
+
diff --git a/src/interface/modeler/quickapp/RenderProcess.cpp b/src/interface/modeler/quickapp/RenderProcess.cpp
index a0fff7a..064b691 100644
--- a/src/interface/modeler/quickapp/RenderProcess.cpp
+++ b/src/interface/modeler/quickapp/RenderProcess.cpp
@@ -211,9 +211,9 @@ void RenderProcess::timerEvent(QTimerEvent *)
         if (rendering)
         {
             unsigned long remaining = renderer->getProgressHelper()->estimateRemainingTime();
-            if (remaining > 10000)
+            if (remaining > 0)
             {
-                t = QTime(0, 0, 0).addMSecs(remaining);
+                t = QTime(0, 0, 0).addMSecs(999 + remaining);
                 info += " - Remaining: ~" + t.toString("hh:mm:ss");
             }
         }
diff --git a/src/render/software/RenderProgress.cpp b/src/render/software/RenderProgress.cpp
index f20eedf..5c5a62d 100644
--- a/src/render/software/RenderProgress.cpp
+++ b/src/render/software/RenderProgress.cpp
@@ -9,8 +9,9 @@ RenderProgress::RenderProgress(int count)
     lock = new Mutex();
     global = 0.0;
     step = 1.0 / (double)count;
-    start_time = Time::getRelativeTimeMs();
+    start_time = 0;
     end_time = 0;
+    reset();
 }
 
 paysages::software::RenderProgress::~RenderProgress()
@@ -30,6 +31,10 @@ void RenderProgress::reset()
 
     start_time = Time::getRelativeTimeMs();
 
+    prev_est_spent = 0;
+    prev_est_done = 0.0;
+    prev_est_speed = 0.0;
+
     lock->release();
 }
 
@@ -94,16 +99,24 @@ unsigned long RenderProgress::getDuration() const
     }
 }
 
-unsigned long RenderProgress::estimateRemainingTime() const
+unsigned long RenderProgress::estimateRemainingTime()
 {
-    if (global < 0.00001)
+    unsigned long spent = getDuration();
+    double speed = (global - prev_est_done) / (double)(spent - prev_est_spent);
+
+    prev_est_speed = prev_est_speed ? (prev_est_speed * 0.8 + speed * 0.2) : speed;
+    if (spent - prev_est_spent > 5000)
     {
-        return 0;
+        prev_est_spent = spent;
+        prev_est_done = global;
+    }
+
+    if (prev_est_speed > 0.0000000001)
+    {
+        return (unsigned long)((1.0 - global) / prev_est_speed);
     }
     else
     {
-        unsigned long done = getDuration();
-        unsigned long total = (unsigned long)((double)done / global);
-        return total - done;
+        return 0;
     }
 }
diff --git a/src/render/software/RenderProgress.h b/src/render/software/RenderProgress.h
index 875b61f..385717a 100644
--- a/src/render/software/RenderProgress.h
+++ b/src/render/software/RenderProgress.h
@@ -42,14 +42,21 @@ public:
      *
      * Returns 0 if unknown.
      */
-    unsigned long estimateRemainingTime() const;
+    unsigned long estimateRemainingTime();
 
 private:
     Mutex *lock;
+
     double global;
     double step;
+
     unsigned long start_time;
     unsigned long end_time;
+
+    unsigned long prev_est_spent;
+    double prev_est_done;
+    double prev_est_speed;
+
     std::stack<RenderSub> subs;
 };