Babylon.js SCREENSHOT MAKER Prototype - quick Screenshot maker prototype.
Based on the example from another thread
It is quite easy to add a possibility to upload GLTF or Babylon files with instant or custom screenshot creation (as well as possibility to choose environment, light and other scene presets).
It is also possible to capture every frame from rendering with high res and record it to disk (needs server-side things). See code example here - Custom Rendering of Scenes to Video