Comment by pixelsynth

There are a lot of tools to do this easily today, for free! Take a look at Postshot, or Brush. You can literally take a video with your mobile phone, toss it in Postshot, and a few minutes later you have a photorealistic 3DGS model you can use in Spark!

3DGS is still a rapidly evolving research field, but the "baseline" is pretty much standard these days.