[x3d-public] [X3D-Ecosystem] proposal for new X3D node: InlineGeometry

[John Carlson]

I know it’s not a great idea, but I’ve also attempted to convert X3D to STL
and PLY.

Specific enhancement requests (with examples) welcome!

https://coderextreme.net/X3DJSONLD/src/main/html/responsive.html

I agree we should pursue glTF splats.   We don’t have point size in X3D
that I know or, it takes a lot of space.

John


On Tue, Feb 10, 2026 at 12:18 PM Don Brutzman via X3D-Ecosystem <
x3d-ecosystem at web3d.org> wrote:

> STL and PLY files are commonly used ways to define mesh geometry, often
> for rendering or for additive manufacturing.  These formats are described at
>
>    - Wikipedia: STL (file format)
>    <https://en.wikipedia.org/wiki/STL_(file_format)>, a file format for
>    3D CAD models
>    - Wikipedia: PLY (file format)
>    <https://en.wikipedia.org/wiki/PLY_(file_format)> or Polygon File
>    Format
>
> Typically if an X3D author wants to use such assets to load a mesh, they
> must be converted into an X3D graph.  That is because the existing X3D
> Inline node results in an X3DChildNode rather than geometry.  Pseudo-X3D
> example:
>
> X3D
>   Scene
>      children [
>          WorldInfo title="MyImportedMeshModel"
>          Group (
>             Shape
>                geometry   *I**ndexedFaceSet DEF="ConvertedFromStlOrPly"*
> *                   Coordinate etc.*
>
> All of these gyrations require the use of a converter.   Incidentally here
> are two excellent converters:
>
>    - Castle Online Converter for 3D and 2D Models
>    - https://castle-engine.io/convert.php
>
> and
>
>    - X_ITE Free Online X3D File Format Converter
>    - https://create3000.github.io/x_ite/laboratory/x3d-file-converter/
>
> Suggestion: why don't we define a new X3D node *InlineGeometry* that
> supports direct loading of STL or PLY geometry files, simplifying the
> current import process.  Possible node interface would be something like
>
>> *InlineGeometry* : X3DGeometryNode, X3DUrlObject {
>>   SFTime   [in,out] autoRefresh          0.0      [0,∞)
>>   SFTime   [in,out] autoRefreshTimeLimit 3600.0   [0,∞)\
>>   SFString [in,out] description          ""
>>   SFBool   [in,out] load                 TRUE
>>   SFNode   [in,out] metadata             NULL     [X3DMetadataObject]
>>   MFString [in,out] url                  []       [URI]
>> }
>>
>> Am thinking that implementers of such a node might use any internal
> representation that they like:  IndexedFaceSet, TriangleSet,
> IndexedStripSet, etc. etc.  How the geometry gets rendered doesn't much
> matter to an end user, they just want the mesh to show up from the STL or
> PLY file.
>
> Example usage:
>
>     Shape
>        appearance Appearance (USE="FancyPaint")
>        geometry* InlineGeometry (url="MyFavoriteMesh.stl")* # direct
> loading eliminates need for conversion
>
> One conceivable alternative is to create a Coordinate node, but that
> approach is insufficient since Coordinate only contains points and all
> connectivity information for the mesh gets lost.   So that won't work, we
> should stick to X3DGeometryNode as the result of the inline geometry import.
>
> Restriction: apparently a recent develop some people are extending PLY
> file format to store gaussian splat information... we likely want to
> exclude such atypical functionality, instead waiting to take advantage of
> emerging glTF support for gaussian splats.
>
> Relevant X3D Architecture specification links:
>
>    - X3D Architecture draft 4.1, 11 Rendering component, 11.3.5
>    X3DGeometryNode
>    <https://www.web3d.org/specifications/X3Dv4Draft/ISO-IEC19775-1v4.1-CD/Part01/components/rendering.html#X3DGeometryNode>
>    - X3D Architecture draft 4.1, 9 Networking component, 9.3.2
>    X3DUrlObject
>    <https://www.web3d.org/specifications/X3Dv4Draft/ISO-IEC19775-1v4.1-CD/Part01/components/networking.html#X3DUrlObject>
>
> I've started a Mantis issue to keep track of distilled commentary, to help
> ensure that we carefully and effectively consider such a powerful
> capability.
>
>    - Web3D Mantis issue tracker 1522: proposed X3D node: InlineGeometry
>    - https://mantis.web3d.org/view.php?id=1522
>
> All feedback welcome.  What do you think?
>
> Have fun with X3D mesh interoperability!  😃  💠
>
> all the best, Don
> --
> X3D Graphics, Maritime Robotics, Distributed Simulation
> Relative Motion Consulting  https://RelativeMotion.info
> --
> X3D-Ecosystem mailing list
> X3D-Ecosystem at web3d.org
> http://web3d.org/mailman/listinfo/x3d-ecosystem_web3d.org
>
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