It’s an action vs a state of being.

I made sure he died is making sure that the action of dying was completed. In that sense it sounds like you contributed to them dying. E.g. a mobster telling his boss he made sure someone died.

I made sure he was dead, is confirming their state of being as dead. E.g. a professional would ensure someone was dead before they’re cremated.

There is a lot of nuance in there though. E.g. a mobster might also make sure someone was dead after e.g. shooting them. (But again it’s checking their state of being rather than ensuring their act of dying was complete. I.e. finishing them off)

You had a good run, almost a year swapping to the world of the walking dead as you closed your eyes at night. But now you realise your luck is up. You fire off your last 5 rounds watching 5 shambling corpses hit the floor.

Putting the revolver to your head and pulling the trigger to end it, you hear an unfamiliar dull thunk instead of a click.

A split second later the rest of the dead reach you. They bite and tear and you feel the virus spread through you. An insatiable hunger for human flesh grows within you. You slowly loose consciousness the hunger growing.

In the back of your mind you’re surprised as you wake back in your original world. Grogglily you roll over in bed to see your wife sleeping next to you. You watch in horror as the virus you’ve carried back to this world moves your body like a puppet, trapped in a small corner of your mind as you start a new zombie outbreak unable to control your own actions.

Others have covered the topic of modern renderers and their shortcuts but if you wanted an exact replica I think films like this are rendered on large HPC clusters.

Looking at the Top500 stats for HPCs the average top500 cluster in 1995 was 1.1TFlops, and today that seems to be around 23.4PFlops.

An increase of approximate 21,000 times.

So 800,000 hours from 1995 is about 37 hours on today’s average top500 cluster.

Edit: I found a few unconfirmed calculations that Toy Story was rendered on 294 CPUs in SPARCstation 20s with a combined power of only 8GFlops. This would mean a render time of 325,000 CPU hours, 1,100 wall clock hours. So, No. 500 of the top500 has the theoretical raw power to render toy story in about 15mins. You’d only need around 7Tflops to render it in it’s 75min runtime.

Still we’re talking multimillion dollar HPC clusters here, not your home rig if you want to render exactly the same thing in the same way.

If you could update the renderer to support modern GPU hardware then it seems like you would have enough power to achieve similar realtime rendering.