[Interest] [Qt3D] Smooth orbit camera

[Oleg Evseev]

Thanks Sean,

There is no any instrument in qt3d animation framework similar to
QuaternionAnimation (a PropertyAnimation for quaternions), isn't there?

2017-05-06 22:26 GMT+03:00 Sean Harmer <sean.harmer at kdab.com>:

> Hi,
>
> On 06/05/2017 19:34, Oleg Evseev wrote:
>
>> Hi Andy,
>>
>> Thanks for tips!
>> I thought about standard animation (it's used in planets example by the
>> way) but I suppose it's better to use FrameAction:
>>
>> https://doc.qt.io/qt-5/qt3dlogic-qframeaction.html#details
>>
>>     The QFrameAction provides a way to perform tasks each frame in a
>>     synchronized way with the Qt3D backend. This is useful to implement
>>     some aspects of application logic and to prototype functionality
>>     that can later be folded into an additional Qt3D aspect.
>>
>>     For example, the QFrameAction can be used to animate a property in
>>     sync with the Qt3D engine where a Qt Quick animation element is not
>>     perfectly synchronized and may lead to stutters in some cases.
>>
>>
>> Maybe this with camera movement is not the "some case".
>>
>> I haven't looked at the new Qt3D animation stuff, but I think its more
>>>
>> geared towards animated models, not moving the camera?
>>
>> I suppose it's for everything related to animation in 3d :)
>>
>
> Yes, you can use it to animate any property. If animating a property of a
> QNode that is known by the aspect backends then it even avoids the
> backend->frontend->backend round trip. For regular QObjects the animation
> is stepped on the backend and property updates sent to the frontend.
>
> Any of the approaches you mention should work fine.
>
> Cheers,
>
> Sean
>
>
>> 2017-05-06 21:22 GMT+03:00 Andy <asmaloney at gmail.com
>> <mailto:asmaloney at gmail.com>>:
>>
>>     Oleg:
>>
>>     The way I did it was to implement a QVariantAnimation-derived class
>>     that stores the QCamera's start &end positions, view centres, and up
>>     vectors. Then I just set the easing curve & the duration I want and
>>     call start(). Works great for my use case.
>>
>>     I haven't looked at the new Qt3D animation stuff, but I think its
>>     more geared towards animated models, not moving the camera?
>>
>>     (In another case I use QPropertyAnimation directly to animate some
>>     arrow drawing in my scene which also works great and is easy to set
>> up.)
>>
>>     ---
>>     Andy Maloney  //  https://asmaloney.com
>>     twitter ~ @asmaloney <https://twitter.com/asmaloney>
>>
>>
>>     On Sat, May 6, 2017 at 1:46 PM, Oleg Evseev <ev.mipt at gmail.com
>>     <mailto:ev.mipt at gmail.com>> wrote:
>>
>>         Hi,
>>
>>         I'm looking for solution to get smooth orbit camera in qt3d.
>>         That is for example when I need to change angle of observe it
>>         doesn't translate camera immediately, but with some delay, just
>>         like in games: when vehicle turn camera follow it with delay.
>>
>>         Does it make sense to use newest Qt3D animation framework (not
>>         yet immersed in the study how to use it), or it would be
>>         overkill for that task and it would be better to write special
>>         camera controller based on QOrbitCameraController with custom
>>         logic for frameAction onTriggered handling?
>>
>>         Maybe there are some relative examples with ready-to-use math?
>>         Will be much appreciate for links.
>>
>>         Thanks for advices!
>>
>>         --
>>         With best regards, Oleg.
>>
>>         _______________________________________________
>>         Interest mailing list
>>         Interest at qt-project.org <mailto:Interest at qt-project.org>
>>         http://lists.qt-project.org/mailman/listinfo/interest
>>         <http://lists.qt-project.org/mailman/listinfo/interest>
>>
>>
>>
>>
>> _______________________________________________
>> Interest mailing list
>> Interest at qt-project.org
>> http://lists.qt-project.org/mailman/listinfo/interest
>>
>>
> --
> Dr Sean Harmer | sean.harmer at kdab.com | Managing Director UK
> KDAB (UK) Ltd, a KDAB Group company
> Tel. +44 (0)1625 809908; Sweden (HQ) +46-563-540090
> Mobile: +44 (0)7545 140604
> KDAB - Qt Experts
>
> _______________________________________________
> Interest mailing list
> Interest at qt-project.org
> http://lists.qt-project.org/mailman/listinfo/interest
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.qt-project.org/pipermail/interest/attachments/20170507/40d3d168/attachment.html>