[x3d-public] X3D Working Group Agenda 28 OCT 2019: consistent rendering, adding features and nodes from v3.3 players

[Andreas Plesch]

Ok.

Yes, turntable navigation mode is really useful. It is probably the
most popular mode in x3dom. It could be specified as a special case of
EXAMINE, with the additional restriction that the vertical axis must
stay aligned with the local Y-axis. Helicopter mode is similar but
with FLY controls.

Out of the other listed nodes, EnvironmentLight is important and
relatively easy to implement in the shader. The light color is
determined from a skybox/environment, relative to the eye-to-fragment
angle. x3dom has it for PBR purposes.

x3dom has BackdropBackground as a special case of Background. It is a
simple static image and can be quite useful:
https://github.com/x3dom/x3dom/issues/971 . If only the backUrl field
is populated, it is used as a static backdrop.

Plane is used but I forget why it is there over Rectangle2D. The extra
geometry nodes are rarely used. Teapot can be useful for testing
across browsers but that is probably not a good reason to expand the
spec.

-Andreas

On Fri, Oct 18, 2019 at 1:36 PM Brutzman, Donald (Don) (CIV)
<brutzman at nps.edu> wrote:
>
> Thanks for feedback Andreas.
>
> On 10/18/2019 4:18 AM, Andreas Plesch wrote:
> >> Date: Fri, 18 Oct 2019 10:33:55 +0000
> >> From: "Brutzman, Donald (Don) (CIV)" <brutzman at nps.edu>
> >> To: X3D Graphics public mailing list <x3d-public at web3d.org>
> >> Cc: X3D Graphics Working Group <x3d at web3d.org>
> >> Subject: [x3d-public] X3D Working Group Agenda 28 OCT 2019: X3Dv4 issues review
> >>
> >> ==================================
> >>[...]
> >> 2. *Carryover issue: material, textures, lighting*
> >>
> >>> a. Good discussion on interplay between materials and textures is occurring on both the X3DOM and X_ITE mailing lists.  [...]
> >>>
> >>> * X3DOM conversation
> >>>     https://github.com/x3dom/x3dom/issues/993
> >>>
> >>> * X_ITE conversation
> >>>     https://github.com/create3000/x_ite/issues/50
> >>
> >> Is this driving to closure satisfactorily? Are precise changes expected for X3Dv4?
> >
> > x3dom has been updated to be more spec. complaint and tries to detect
> > if an image texture is greyscale from the image itself now.
> >
> > Michalis has good language for precise changes which would much
> > simplify image texture and color mixing by always just multiplying.
> > x3dom would likely support this change. Probably x-ite as well since
> > it makes implementations and reasoning easier.
> >
> >> We must have consistent rendering well defined.
> >
> > Currently, it is not very well defined. The changes would make it more
> > consistent with other graphics systems.
>
> Super.  Looking forward to compatible resolution between X3DOM, X_ITE, Castle Game Engine and then X3Dv4 PBR.
>
> You have our commitment to have the specification match consensus on repeatable authoring results for rendering.
>
> Hopefully other implementers are taking advantage of considering these discussion threads as well.
>
> >> ==================================
> >>
> >> 3. *Carryover issue: features and nodes*
> >>
> >>> b. X3DOM and X_ITE have added some navigation types and other special features.  Some features will also be part of SAI, for example getting screen-space coordinates.  We need to expose these inside any X3D model so that authors work to best effect with HTML5.  These need to be considered and proposed publicly to get on the X3D Working Group agenda prior to 16 DEC 2019.
> >>>
> >>> The community has to live with the results... the community should *Step Up to Help* !!  This is a real opportunity for authors and implementers to speak out, helping to elevate important new candidate capabilities.
> >>
> >> Nobody has stepped up yet.  Navigation types and other geometry nodes sure seem like low-hanging fruit.
> >
> > I gather this issue is mostly with respect to VR navigation ? I am not
> > sure what this issue is about.
>
> Yes, X3DOM X_ITE and other browsers' documentation have noted some additional navigation types and additional geometry nodes.  For example:
>
>         https://www.x3dom.org/new-turntable-navigation-mode-in-x3dom
>         https://www.x3dom.org/x3dom/example/x3dom_turntable.html
> and
>         X3DOM node index
>         https://doc.x3dom.org/author/nodes.html
>
> includes Block, Dish, ImageGeometry, Mesh, Multipart, Nozzle, Plane, Pyramid, RectangularTorus, SlopedCylinder, Snout, SolidOfRevolution, SphereSegment, Torus, Viewfrustum.
>
>         X_ITE Supported Nodes
>         http://create3000.de/x_ite/supported-nodes
>
> ... has BlendMode (not sure why).  Otherwise mostly appears to match the spec, but doubtless has some suggested changes or additions to X3D.
>
>         http://create3000.de/users-guide/components/x_ite/blendmode
>
> Instant Reality has numerous variants, not sure what might be repeatable/generalizable.  Perhaps PixelText, SolidText, SphereSegment, Torus, Plane, ImageGeometry, Teapot, SphericalHarmonics, Highlight, EnvironmentLight, BackdropBackground, GradientBackground, SolidBackground, PolygonBackground, SkydomeBackground, many others are also listed.
>
>         http://doc.instantreality.org/documentation/nodetypetree
>
> Am expecting Castle Game Engine and FreeWrl also have wish lists.
>
> Not looking for "node bloat" but many of these sound quite simple and might be good additions to X3Dvy author's palette of capabilities.
>
> Thanks everyone for considering the possibilities.  As before:
>
> >> Seems like a real opportunity for someone to unlock major latent improvements for future authors and users.
> >>
> >> Am willing to spend meeting time to review once a suggestion list has been posted publicly.
> all the best, Don
> --
> Don Brutzman  Naval Postgraduate School, Code USW/Br       brutzman at nps.edu
> Watkins 270,  MOVES Institute, Monterey CA 93943-5000 USA   +1.831.656.2149
> X3D graphics, virtual worlds, navy robotics http://faculty.nps.edu/brutzman



-- 
Andreas Plesch
Waltham, MA 02453