[x3d-public] InlineGeometry node and PLY format support in Castle Game Engine

[Michalis Kamburelis]

With big thanks to Don who provided information and pushed me to implement it!:)

1.  We support now InlineGeometry in Castle Game Engine and Castle Model Viewer.

    - I tested on a few examples, and made our own: https://github.com/castle-engine/demo-models/tree/master/x3d/inline_geometry

    - You can refer to a geometry from any model format we support, including X3D, glTF, STL, PLY...: https://castle-engine.io/model_formats

2.  We support now loading models in a PLY format.

    - ASCII and binary versions.

    - Faces or without faces (point cloud, i.e. just our PointSet).

    - Testcases include https://github.com/castle-engine/demo-models/tree/master/ply and https://sketchfab.com/3d-models/kaktus-ply-7b7cc7188f17468595506500e186a9c0 .

More information and screenshots about both features in our news post on https://castle-engine.io/wp/2026/04/06/support-for-ply-model-format-and-inlinegeometry-node/ .

They are available to test right now if you download 
- the "snapshot" version of Castle Model Viewer https://castle-engine.io/castle-model-viewer 
- or full engine from https://castle-engine.io/download .

Regards,
Michalis