SaveNode GLTF support

[peardox]

I notice that PasGLTF is read/write so this feature is desirable and appears already possible (to an extent?)

x3d files are massive while glb would be a lot more reasonable

[michaliskambi]

Yes, this is planned.

• SaveNode should support glTF output,
• our command-line converter tovrmlx3d (distributed with https://castle-engine.io/view3dscene.php ) should support it too, and be renamed castle-asset-converter

[michaliskambi]

I just finished a few "prerequisites" of it.

Namely, we had some hardcoded assumptions in our infrastructure that "X3D is the only model format we can write". They are all gone now :) This means that

• SaveNode can now save other model formats. The first, aside from X3D, is STL -- as the simplest model format in the world, STL was nice to quickly test things :)
• tovrmlx3d is now named castle-model-converter and supports command-line that allows to provide output type. ( https://castle-engine.io/castle-model-converter ). castle-model-converter input.x3d output.stl now works.
• view3dscene is now castle-model-viewer and the "Save As" dialog allows to choose any supported output extension, including STL ( https://castle-engine.io/castle-model-viewer )
• and even our online converter ( https://castle-engine.io/convert.php ) now supports other output formats. Again, the first new output format is STL, in addition to X3D.

I will announce it soon along with castle-model-viewer 4.4.0 release.

This opens the door for upcoming glTF output.