Re: [Interest] Qt3D performance, and development resources
Thanks to all for the interesting C++ Qt3D links! I long wanted to play with Qt3D in C++. RHI supporting all major 3D APIs makes it really attractive. Christoph Feck ___ Interest mailing list Interest@qt-project.org https://lists.qt-project.org/listinfo/interest
Re: [Interest] Qt3D performance, and development resources
For anyone interested in more code examples, I've written some rendering tools using Qt3D in C++. https://github.com/unclejimbo/Klein Hope this helps. Nyall Dawson 于2020年4月15日周三 下午12:45写道： > On Wed, 15 Apr 2020 at 01:51, Charles Martin wrote: > > > - Where can I find more examples, tutorials and introductory > information? There are only two C++ examples on the Qt website, and both of > these are very simple. The Qt docs are very limited and incomplete. > > There's some good ones here: > > https://github.com/wonder-sk/qt3d-experiments > > > - Is there a community of C++ Qt3D developers? Most online material > was produced by KADB, is 4 years or older, and focuses on QML. Where are > the C++ users? > > The QGIS desktop application is a c++ application which makes heavy > use of Qt 3d. You may find some useful code in > https://github.com/qgis/QGIS/tree/master/src/3d. > > Nyall > ___ > Interest mailing list > Interest@qt-project.org > https://lists.qt-project.org/listinfo/interest > ___ Interest mailing list Interest@qt-project.org https://lists.qt-project.org/listinfo/interest
Re: [Interest] Qt3D performance, and development resources
On Wed, 15 Apr 2020 at 01:51, Charles Martin wrote: > - Where can I find more examples, tutorials and introductory information? > There are only two C++ examples on the Qt website, and both of these are very > simple. The Qt docs are very limited and incomplete. There's some good ones here: https://github.com/wonder-sk/qt3d-experiments > - Is there a community of C++ Qt3D developers? Most online material was > produced by KADB, is 4 years or older, and focuses on QML. Where are the C++ > users? The QGIS desktop application is a c++ application which makes heavy use of Qt 3d. You may find some useful code in https://github.com/qgis/QGIS/tree/master/src/3d. Nyall ___ Interest mailing list Interest@qt-project.org https://lists.qt-project.org/listinfo/interest
Re: [Interest] Qt3D performance, and development resources
Hi, Qt3D performance on Android was my concern a year ago too: https://bugreports.qt.io/browse/QTBUG-72808 (see also https://bugreports.qt.io/browse/QTBUG-73057) especially when Scene3D with multi sampling is used. Using OnDemand policy improve performance (but almost in stale scenes), take a look. I thought that new Underlay compositingMode introduced in 5.14 ( https://doc.qt.io/qt-5/qml-qtquick-scene3d-scene3d.html#compositingMode-prop) will increase performance twice or even more, but unfortunately I didn't see any increase at least in our case and hardware. But you can take a look to it. But just in case, note about bug Scene3D.Underlay + OnDemand (QTBUG-82861) About examples. First of all, take look at Qt 3D examples especially manual tests as Mike Krus rightly suggested. I can't be supportive but if you want, you can take a look to several simple apps I made for test case in bug reports, may be there will be useful somehow for you. I used Qt3D in C++ inside World3d as the root object of QML Scene3D (several test examples can be similar in fact). QTBUG-80092, QTBUG-60612, QTBUG-60429, QTBUG-60183, QTBUG-50720 p.s. I will also take the opportunity to express here my pains about Qt3D a little :) Our project is based on Qt3D and it is really nice and handy, but we stack with Qt 5.9.5. With some workarounds it get turn out as most stable version for us, every time we try to move to newer version 5.10, 5.11, 5.12, 5.14 we are always encountered with bugs and crashes. And the most upset that several of them were repeated in next versions after fixes :( Unfortunately now I don't have enough time to test and post bugrepost, hope latter I can help to improve Qt 3d a little. Despite any issues, thank all Qt developers and community for their work! --- With regards, Oleg вт, 14 апр. 2020 г. в 18:50, Charles Martin : > I’ve been migrating a C++ Coin/Quarter project to Qt3D. I’m doing this on > a newer iMac/Catalina. The graphics performance seems unacceptable. A > simple display of 3600 line segments takes about 5 seconds to render and > 30k segments takes >30 seconds. > > When the rendering is started, Qt puts out this warning message: > qt.qpa.openglcontext: Could not create NSOpenGLContext with shared > context, falling back to unshared context. > > I’m new to Qt3D, and there is a good chance that I’m doing something wrong. > > My questions: > > - Shouldn't I see better performance, and what can I try to improve > that? Does the warning message identify the problem? > > - Where can I find more examples, tutorials and introductory information? > There are only two C++ examples on the Qt website, and both of these are > very simple. The Qt docs are very limited and incomplete. > > - Is there a community of C++ Qt3D developers? Most online material was > produced by KADB, is 4 years or older, and focuses on QML. Where are the > C++ users? > > I’m trying to get some traction with this product, and any guidance is > really appreciated. > > Thanks, > Charlie > > > > ___ > Interest mailing list > Interest@qt-project.org > https://lists.qt-project.org/listinfo/interest > ___ Interest mailing list Interest@qt-project.org https://lists.qt-project.org/listinfo/interest
Re: [Interest] Qt3D performance, and development resources
Hi Charlie > On 14 Apr 2020, at 16:51, Charles Martin wrote: > > I’ve been migrating a C++ Coin/Quarter project to Qt3D. Fun. A long time since I used Coin3d. Keep meaning to port it’s scxml based camera controller and the manipulators to qt3d. > I’m doing this on a newer iMac/Catalina. The graphics performance seems > unacceptable. A simple display of 3600 line segments takes about 5 seconds to > render and 30k segments takes >30 seconds. Can you explain how the scene graph is structured? Is each line segment a separate entity plus its components? Or just a single entity? If each line is an object then I would totally expect the kind of performance you are getting as each object will result is a draw call. That number of draw calls alone will kill performance. > When the rendering is started, Qt puts out this warning message: > qt.qpa.openglcontext: Could not create NSOpenGLContext with shared context, > falling back to unshared context. That is odd. Could you explain how you are setting up your window? > I’m new to Qt3D, and there is a good chance that I’m doing something wrong. > > My questions: > > - Shouldn't I see better performance, and what can I try to improve that? > Does the warning message identify the problem? I would say it’s either the number of objects or indeed the fact that context are not shared (resulting in lots of context switches). Qt3d 5.15 ships which new performance tracking features that may help you investigate. See https://www.kdab.com/debugging-profiling-qt-3d-apps/ > - Where can I find more examples, tutorials and introductory information? > There are only two C++ examples on the Qt website, and both of these are very > simple. The Qt docs are very limited and incomplete. Qt 3D itself ships with a number of examples. If you look at the Qt 3D source code, there’s a number of manual tests which may be of interest. KDAB’s GitHub has a qt3d sample project which has other examples, though they may be a bit outdated. > - Is there a community of C++ Qt3D developers? Most online material was > produced by KADB, is 4 years or older, and focuses on QML. Where are the C++ > users? We are here :) Please note that although many exemples are in qml, they are still relevant for your use case as the APIs are nearly identical. > I’m trying to get some traction with this product, and any guidance is really > appreciated. Feel free to get in touch if you need more help. Mike > Thanks, > Charlie > > > > ___ > Interest mailing list > Interest@qt-project.org > https://lists.qt-project.org/listinfo/interest ___ Interest mailing list Interest@qt-project.org https://lists.qt-project.org/listinfo/interest
[Interest] Qt3D performance, and development resources
I’ve been migrating a C++ Coin/Quarter project to Qt3D. I’m doing this on a newer iMac/Catalina. The graphics performance seems unacceptable. A simple display of 3600 line segments takes about 5 seconds to render and 30k segments takes >30 seconds. When the rendering is started, Qt puts out this warning message: qt.qpa.openglcontext: Could not create NSOpenGLContext with shared context, falling back to unshared context. I’m new to Qt3D, and there is a good chance that I’m doing something wrong. My questions: - Shouldn't I see better performance, and what can I try to improve that? Does the warning message identify the problem? - Where can I find more examples, tutorials and introductory information? There are only two C++ examples on the Qt website, and both of these are very simple. The Qt docs are very limited and incomplete. - Is there a community of C++ Qt3D developers? Most online material was produced by KADB, is 4 years or older, and focuses on QML. Where are the C++ users? I’m trying to get some traction with this product, and any guidance is really appreciated. Thanks, Charlie ___ Interest mailing list Interest@qt-project.org https://lists.qt-project.org/listinfo/interest
