If a Shapecast is run under the exact same conditions on the client and on the server, you get two results depending on your environment.
- Under Roblox Studio, both the client and the studio report the same value
- Under Live servers, client and servers report different values
Under both environments, the result is the same at each run
I am linking to this post a RBXL file that you can run in Studio and in Live environment to see the difference
shapecast_test.rbxl (67.9 KB)
(the results can be seen on the console)
Expected behavior
It should be expected to see the same results on the Studio and in the live environment (especially in context where the inaccuracy can be accumulated)
Please note that a similar topic has been brought for Spherecasts with this topic:
https://devforum.roblox.com/t/spherecast-result-on-server-and-client-is-different-in-live-servers/2660896/5
However, the last post states a floating point compression issue, which is clearly not the case in my post (because the data is not transmitted, only printed in console)
There are probably not a lot of consequences of such inaccuracy.
But in the game I am working on, this causes an insane amount of tiny jitters when walking (because the system relies on server authoritative model), and we can feel something is wrong (thing which doesn’t happen in Studio, even under high ping simulations)