[Interest] Qt3D How to draw 2D-Text always facing the Camera

[Volker Enderlein]

Hi Oleg,

thank you so much for your comment. I saw your entry in the bug tracker 
and therefore I tried to go the way with the custom material. 
Unfortunately I cannot access the underlying material definition of the 
utility classes that are used to render the text in Text2DEntity. As 
they are all private and not exported from Qt DLLs I would need to copy 
them, but that's something I would really try to avoid. The custom 
material part was straight forward, based on your bug report and on a 
previous implementation of a specialized material definition.
But now I'm stuck with the missing access.

Cheers Volker

Am 18.12.2018 um 13:38 schrieb Oleg Evseev:
> Hi Volker,
>
> Yes, you have to add custom material because 
> Qt3DRender::QShaderProgram s of default materials are inside private 
> class, so you can't change shaders' code source.
>
> Take a look at https://codereview.qt-project.org/#/c/182053/ (that was 
> for including in qt 3d, but you could easily use it as custom material 
> in your own app) and adopt it accordingly to Text2DMaterial.
>
> ---
> With regards, Oleg
>
> вт, 18 дек. 2018 г. в 15:07, Volker Enderlein 
> <volker.enderlein at ifm-chemnitz.de 
> <mailto:volker.enderlein at ifm-chemnitz.de>>:
>
>     Hi all,
>
>     when building a rather complex Qt3D-Scene I needed some 2D-Text
>     that has
>     a 3D position, is always facing the camera, and fixed in size,
>     independent of the camera settings.
>
>     While looking over the components provided by Qt3D I stumbled across
>     Text2DEntity and thought about how it can be tweaked ot fulfill my
>     requirements.
>
>     As all my requirements can be done inside a shader I thought about
>     whether the QText2DMaterial that is used inside the class can be
>     replaced by a custom material. But unfortunately the material is not
>     accessible from outside.
>
>     Text2DEntity can be embedded in another class that applies the camera
>     information to it, but is there an easier solution to this problem?
>
>     Cheers Volker
>
>     -- 
>
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