[x3d-public] Specification editors mantis issues, PointProperties

Fri Sep 4 11:39:45 PDT 2020

Hi Michalis,

Very nice wiki entry, I took the liberty to add a suggestion to
https://github.com/michaliskambi/x3d-tests/wiki/Points-and-lines-rendering
:

6. Full textures are applied to each point so they cover completely a
square region around each point. The size of the region may vary
depending on PointProperties.

This is just a suggestion. Feel free to edit freely, including
removing the line.

Perhaps it is worth also adding that explicit TextureCoordinate values
would be ignored. ( In theory, this could also lead to non-sprite
rendering but I am not sure if there is a use case for that. )

Is there currently guidance on how thick lines should be textured if
at all ? Eg. how to derive texture coordinates for thick lines ?

Thanks, -Andreas

On Fri, Sep 4, 2020 at 11:52 AM Michalis Kamburelis
<michalis.kambi at gmail.com> wrote:
>
> > > "If the normal field of the PointSet node contains normal vectors, then points are rendered using the same lighting equations as the other geometry and can be lit. If the normal vectors are not provided, the points are rendered following the "unlit" lighting equations. If the PointSet is used with the Material node, and the normal vectors of points are not provided, the points shall be rendered as unlit, using the emissiveColor field of the Material node. In both cases, the points look can be customized using textures, Color, ColorRGBA, and UnlitMaterial nodes."
>
> > That sounds great, and should cover all situations.
>
> Happy to hear that! :)
>
> I wrote a quick summary of our changes for point/lines rendering prose on https://github.com/michaliskambi/x3d-tests/wiki/Points-and-lines-rendering . The short version is: it is simple now :), as consistent with other geometry as technically possible.
>
> Regards,
> Michalis
>
> pt., 4 wrz 2020 o 00:07 Andreas Plesch <andreasplesch at gmail.com> napisał(a):
>>
>> Since both x_ite and
>>
>> http://metagrid2.sv.vt.edu/~yansh93/archimedes_pp_normal.html
>>
>> use circles for point rendering, this x3dom draft implementation now
>> also uses circles:
>>
>> https://raw.githack.com/andreasplesch/x3dom/PointSetNormals/test/regression-suite/test/cases/points/pointset_archie_normal.html
>>
>> Circles are only used for untextured points. For textured points, eg.
>> sprites, the masking for circles will be omitted.
>>
>> Should the spec. require circles for untextured points ? They look
>> better but perhaps such a requirement is too opinionated.
>>
>> -Andreas
>>
>> On Thu, Sep 3, 2020 at 4:33 PM Andreas Plesch <andreasplesch at gmail.com> wrote:
>> >
>> > I updated the implementation and the scene to reflect the latest
>> > changes in the spec. draft:
>> >
>> > https://raw.githack.com/andreasplesch/x3dom/PointSetNormals/test/regression-suite/test/cases/points/pointset_archie_normal.html
>> >
>> > There are no visual differences.
>> >
>> > -Andreas
>> >
>> > On Thu, Sep 3, 2020 at 4:08 PM Andreas Plesch <andreasplesch at gmail.com> wrote:
>> > >
>> > > I had some time to refocus on PointProperties and found this note on
>> > > spec. changes:
>> > >
>> > > > Date: Mon, 31 Aug 2020 10:33:40 -0700
>> > > > From: Don Brutzman <brutzman at nps.edu>
>> > > > To: Michalis Kamburelis <michalis.kambi at gmail.com>,
>> > > >         "puk at igraphics.com" <puk at igraphics.com>
>> > > > Cc: X3D Graphics public mailing list <x3d-public at web3d.org>
>> > > > Subject: Re: [x3d-public] Specification editors mantis issues: PBR
>> > > >         review
>> > > > ..
>> > > > On 8/24/2020 12:48 PM, Michalis Kamburelis wrote:
>> > > > >
>> > > > > [...]
>> > > > > Answers are inline below.
>> > > > >
>> > > > > Don Brutzman <brutzman at nps.edu <mailto:brutzman at nps.edu>> wrote:
>> > > > >
>> > > > >     ---
>> > > > >     2. Spec questions.
>> > > > >
>> > > > >     a. see new inquiries today regarding PointProperties from Andreas and Holger.? Let's continue/contribute on that thread please.
>> > > > >
>> > > > > I do not see input from Holger in the PointProperties thread. If there's some communication off-list, maybe because someone forgot to use "Reply All", please resend it to the mailing list :)
>> > > >
>> > > > Separate thread found at
>> > > >
>> > > > [1] [x3d-public] PointProperties revisited
>> > > >      https://web3d.org/pipermail/x3d-public_web3d.org/2020-August/013447.html
>> > > >
>> > > > We agreed to remove 'colorMode' and updated both spec & Mantis 1252.
>> > > >
>> > > > We replaced final 2 paragraphs in 11.4.11 PointSet with
>> > > >
>> > > > "If the normal field of the PointSet node contains normal vectors, then points are rendered using the same lighting equations as the other geometry and can be lit. If the normal vectors are not provided, the points are rendered following the "unlit" lighting equations. If the PointSet is used with the Material node, and the normal vectors of points are not provided, the points shall be rendered as unlit, using the emissiveColor field of the Material node. In both cases, the points look can be customized using textures, Color, ColorRGBA, and UnlitMaterial nodes."
>> > >
>> > > That sounds great, and should cover all situations.
>> > >
>> > > I developed a first implementation of PointProperties with normals,
>> > > ignoring textures for now:
>> > >
>> > > https://raw.githack.com/andreasplesch/x3dom/PointSetNormals/test/regression-suite/test/cases/points/pointset_archie_normal.html
>> > >
>> > > This is the archie example modified to use a diffuseColor material for
>> > > shading with normals, and a non-default attenuation factor of "1 1 0",
>> > > eg. with a linear distance dependence.
>> > >
>> > > The point size attenuation looks similar to how x_ite is scaling
>> > > (x_ite ignores the normals currently), so that is good sign. Here is
>> > > the x3d xml version:
>> > >
>> > > https://raw.githubusercontent.com/andreasplesch/x3dom/PointSetNormals/test/regression-suite/test/cases/points/pointset_archie_normal.x3d
>> > >
>> > > freeWrl 4.7 does not seem to do the size attenuation with distance,
>> > > not sure if it is not implemented or another interpretation.
>> > >
>> > > Oh, I see that this draft
>> > >
>> > > https://www.web3d.org/specifications/X3Dv4Draft/ISO-IEC19775-1v4-WD2/Part01/components/shape.html#PointProperties
>> > >
>> > > changed the attenuation field from MFFloat to SFVec3f, and the name
>> > > from pointSizeAttenuation to just attenuation. Should be a quick fix.
>> > >
>> > > In the same spirit, I would also suggest renaming "pointSizeMinValue"
>> > > to "pointSizeMin" or just "sizeMin" (we are in _Point_Properties,
>> > > after all), and "pointSizeMaxValue" accordingly.
>> > >
>> > > -Andreas
>> > >
>> > > --
>> > > Andreas Plesch
>> > > Waltham, MA 02453
>> >
>> >
>> >
>> > --
>> > Andreas Plesch
>> > Waltham, MA 02453
>>
>>
>>
>> --
>> Andreas Plesch
>> Waltham, MA 02453
>>
>> _______________________________________________
>> x3d-public mailing list
>> x3d-public at web3d.org
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-- 
Andreas Plesch
Waltham, MA 02453