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  1. Qt
  2. QTBUG-74103

An empty Scene3D causes a high CPU load

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    Details

    • Type: Bug
    • Status: Reported
    • Priority: P1: Critical
    • Resolution: Unresolved
    • Affects Version/s: 5.12.2
    • Fix Version/s: None
    • Component/s: Qt3D
    • Labels:

      Description

      This bug report was cloned from AUTOSUITE-798. Further investigations has shown that a similar problem occurs on a pure desktop build with not Qt Auto components involved. See comments on AUTOSUITE-798. Below is an extract:

      **

      desktop:

      OS: Ubuntu 16.04 xenial
      Kernel: x86_64 Linux 4.15.0-45-generic
      Resolution: 5360x1440
      DE: Unity 7.4.5
      WM: Compiz
      WM Theme: Ambiance
      Icon Theme: ubuntu-mono-dark
      Font: Ubuntu 11
      CPU: Intel Core i7-7700 CPU @ 4.2GHz
      GPU: Mesa DRI Intel(R) HD Graphics 630 (Kaby Lake GT2)
      RAM: 11010MiB / 15905MiB

       echo $XDG_SESSION_TYPE -> X11

      build with self-built Qt version 5.12.2 as:

      /opt/checkout/qtbase/configure -top-level -opensource -confirm-license -nomake examples -nomake tests -opengl es2 -prefix /opt/qt/auto/5.12.2
      rev: 83d5226604365756adae991c4787edaf6d6b5c6e

       

      1 window:

      import QtQuick 2.9
      import QtQuick.Window 2.2
      
      import QtQuick.Scene3D 2.0
      
      Window {
          visible: true
          width: 1920
          height: 1080
      
          Scene3D {
              id: scene3d
              anchors.fill: parent
          }
      }
      

      Self-built Qt: ~9%cpu

      2 windows:

      import QtQuick 2.9
      import QtQuick.Window 2.2
      
      import QtQuick.Scene3D 2.0
      QtObject {
          property Window w1: Window {
              visible: true
              width: 1920
              height: 1080
      
              Scene3D {
                  id: scene3d
                  anchors.fill: parent
              }
          }
      
          property Window w2: Window {
              visible: true
              width: 1920
              height: 1080
      
              Scene3D {
                  id: scene3d2
                  anchors.fill: parent
              }
          }
      }
      
      

      ~ 13-14%

       

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              Assignee:
              seanharmer Sean Harmer
              Reporter:
              grigorii grigorii zimin
              Votes:
              1 Vote for this issue
              Watchers:
              9 Start watching this issue

                Dates

                Created:
                Updated:

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