[Interest] [Qt3D] Distance field and texture atlas

[Xavier Bigand]

I realize that we can certainly improve the rendering of elements like
openings,... by generating a geometry based on lines (bezier,...). This
will remove the usage of textures and it can be scaled while preserving the
line width.

In this case distance field will be useful mostly for texts.

It make sense that the distance field require a particular material, but
maybe Qt can provide some helper functions to generate the particular
texture containing the distance field.

It will be great to have it in Qt 5.8.


2016-04-21 16:04 GMT+02:00 Xavier Bigand <flamaros.xavier at gmail.com>:

> I am working on an architecture and design software.
>
> There is a lot of feature in Qt3D that interest us for our software, I
> already have made a prototype based on Qt3D as replacement of our homebrew
> 3D engine.
>
> I am interesting in improving rendering of 2D elements :
> [image: Images intégrées 2]
> As you can see with our engine the scale can cut texts and grips aren't
> well filtered. Using distance field can help a lot because all elements can
> be scaled during the zoom.
>
> PS: We also think to add MSAA filtering
>
>
>
>
>
> 2016-04-21 15:02 GMT+02:00 Sean Harmer <sean.harmer at kdab.com>:
>
>> Hi,
>>
>> On Thursday 21 April 2016 14:50:55 Xavier Bigand wrote:
>> > I know that QtQuick already manage the distance field for text elements,
>> > but I want to be able to use it with Qt3D too.
>> > Our Qt3D objects are managed in C++ code not in QML, we prefer to not
>> bind
>> > those elements in QML because of the memory overhead.
>>
>> Oh sorry, I didn't realise you were talking about Qt 3D. Qt 3D does not
>> use
>> distance fields at all in any out of the box materials at this stage. You
>> will
>> need to write a custom Material/Effect to sample from the distance
>> fields. Can
>> you elaborate a bit on your particular use case please? Maybe this is
>> something we can integrate for Qt 5.8?
>>
>> > Does the backend of QML and Qt3D share the same Rendering backend?
>>
>> No. The integration point is in the Scene3D item. Other than that Qt 3D is
>> distinct from Qt Quick.
>>
>> Cheers,
>>
>> Sean
>>
>> >
>> > 2016-04-21 14:34 GMT+02:00 Sean Harmer <sean.harmer at kdab.com>:
>> > > On Thursday 21 April 2016 12:51:27 Xavier Bigand wrote:
>> > > > Hi,
>> > > >
>> > > > Is there any plans to let the user control distance field and
>> texture
>> > >
>> > > atlas?
>> > >
>> > > > We are interested by the distance field for text and icons
>> rendering as
>> > >
>> > > we
>> > >
>> > > > apply scale and rotation on some small elements. We have to much
>> > > > elements
>> > > > to regenerate textures at the right size from svg or ttf, and doing
>> a
>> > >
>> > > cache
>> > >
>> > > > can consume a lot of memory.
>> > >
>> > > What do you want to control? QML text elements use a distance field
>> glyph
>> > > cache
>> > > out of the box (unless you force it to native rendering). I think the
>> > > vertical
>> > > size of this is hard wired for now. In theory it could be exposed.
>> > >
>> > > Afaik Image elements don't use a distance field at all, so you would
>> need
>> > > to
>> > > write a custom QQuickItem plus material to make use of distance fields
>> > > here.
>> > >
>> > > > Texture atlas can also a good thing to improve performances, but
>> with
>> > > > new
>> > > > API that are coming like vulkan the interest will decrease, so this
>> > >
>> > > feature
>> > >
>> > > > will be interesting only for few years.
>> > >
>> > > That assumes a backend to Qt Quick that uses something which supports
>> > > bindless
>> > > textures.
>> > >
>> > > Cheers,
>> > >
>> > > Sean
>> > > --
>> > > 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
>>
>> --
>> 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
>>
>
>
>
> --
> Xavier
>



-- 
Xavier
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.qt-project.org/pipermail/interest/attachments/20160425/ac4dff40/attachment.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image.png
Type: image/png
Size: 551290 bytes
Desc: not available
URL: <http://lists.qt-project.org/pipermail/interest/attachments/20160425/ac4dff40/attachment.png>