[Interest] [Qt3D] What are active render targets for a ScreenRayCaster?

[Volker Enderlein]

Hi Mike,

thanks a lot for your valuable clarifications. When talking about the 
main area you mean the area where the three cameras overlap (two 
orthographic and one perspective)? I always get three hitsChanged 
signals emitted in this area, no matter where I click onto.
I see if I can put up a simple example that shows the mentioned behaviour.

Cheers, Volker

Am 28.03.2019 um 14:35 schrieb Mike Krus:
> Hi Volker
>
> if I remember correctly, ray casting will apply to all enabled surfaces. It’ll ignore off screen surfaces and surfaces where the cursor is outside the render area. I think it also ignores surfaces when an orthographic camera is used.
>
> So in your case sounds like you should only get a single hit in the main area, and two when testing in the render areas.
>
> 5.13 is introducing a QNoPicking frame graph node to explicitly disable picking and ray casting on portions of the frame graph.
>   
> If you continue having issues with this, please create a JIRA ticket, ideally with a small example.
>
> Regards,
> Mike
>
>> On 28 Mar 2019, at 11:13, Volker Enderlein <volker.enderlein at ifm-chemnitz.de> wrote:
>>
>> Hi,
>>
>> The KDAB article https://www.kdab.com/new-in-qt-3d-5-11-generalized-ray-casting/ states that the ScreeenRayCast test is performed for every active render target. I just stumbled over the question what an active render target is considered for a ScreenRayCaster.
>>
>> My FrameGraph contains an orthographic background viewport/camera, a SceneGraph viewport/camera and an orthographic overlay viewport/camera that fill the entire normalized viewport.
>>
>> Additionally two smaller viewport/camera exist at the bottom of the window for an axis gnomon and a fps counter.
>>
>> When triggering a ScreenRayCaster test with the current mouse position the hitsChanged signal is emitted multiple times with different hits.
>>
>> Traversing the scenegraph upwards from the hitted entity (mostly a DistanceFieldTextRenderer is hit) leads me to entities that let me doubt on the returned hit.
>>
>>
>> Anyone out there who can shed some light on it? Thanks in advance.
>>
>>
>> Cheers, Volker
>>
>> -- 
>>
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> —
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> KDAB (UK) Ltd., a KDAB Group company
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