3 ms·

Why do all physics engines still look so floaty?

• jackling 6mo ago
  Can you elaborate on what you mean? It could be a matter of perspective, For a stack of blocks, each 1 meters high, the stack can get quite high and your expectations on how it should look like IRL might not be correct, due to never experience a large tower of blocks being knocked over at that vantage point. Especially if the mass of the objects are strange (super light for their size or super heavy). I know in older games, the recommendation was to keep gravity low (~6 m/s^2 iirc) to help with simulation stability and make things look better, that might contribute to your idea of things being floaty. I don't find the examples in the git repo to be especially floaty, but I work with a lot of simulators so I might just be used to it.
• 10000truths 6mo ago
  One or more of: * Low gravity * Slow timestep * Unrealistic mass ratios of colliding bodies * Incorrect, or lack of, drag
  • fc417fc802 6mo ago
    The timestep effect is remarkable. I was quite surprised with a basic PBD simulation when I lowered the timestep into the nanosecond (IIRC, anyway it was really small and no longer ran in real time) range just to see what would happen and got lots of high frequency shivering effects that looked exactly like what happens IRL when metal objects are fed through a shredder.
    • jackling 6mo ago
      Never tried with that low of a timestep, wonder if that could start causing floating point issues which will lead to more instability.
      • fc417fc802 6mo ago
        Yeah I did have to refactor slightly to minimize precision related impacts.