But I also don't think it's 'obviously' untrue. Yes, the level of detail is mind boggling. But quite a lot of that detail follows naturally from the framework itself: The complexity of an object moving through space and time, interacting with heat and light and atmosphere and etc. is huge. However once the framework is in place (physical laws, light models, properties of materials and so on) everything happens 'naturally' provided you have the processing power to render all the variables.
It's not difficult to imagine a point where a detailed enough framework, and the processing power to render it, could exist. Not soon, but eventually.
Add to that the established tendency of our minds to normalize (ignore things that don't seem to fit, rationalize and otherwise edit reality for palatability) and the power of our neurotransmitter systems to override rational thought... The biological interpreter of the theoretical simulation is well designed to be fooled given a deep enough understanding of it's workings. Which is also not difficult to imagine as a future possibility.
Still, not likely, but too compelling a thought experiment to call bunk IMO.