LuxCoreRender caustic baking test

Description

This is a very first test of [LuxCoreRender](https://www.luxcorerender.org) caustic baking and glTF exporting. As far as I know, it has never been done before. The baking process uses both path tracing and light tracing to render the baked map. For reference, this is the original rendering with [LuxCoreRender](https://www.luxcorerender.org):  Note: Using now Sketchfab glass to fake the glass cube.