# Precision of collisions (how to improve?)

#1

I made some minimechanism of flat golf game, but problem is that from time to time ball flies through the ground. Ground has “mesh” type shape for colissions. Ball is “Sphere” type.
Changing properties of rigid body world like “Steps per second” or "“Solver iterations” doesnt change situation. Is there any other workaround for precision of simulation?

https://youtu.be/rPqxJvmmQpk
Here is video showing problem, video has low framerate thats why movement looks not very fluent.

Looks like the problem appears on big angles (close to perpendicular), so its kind of “tunelling” effect

#2

Please update this thread if you find a solution, I will try as well.

#3

I checked with BGE Bullet and its the same result, this kind of small ball quite often is tunelling through wall/terrain.
I think it needs some special implementation like one of solutions on this page:https://www.aorensoftware.com/blog/2011/06/01/when-bullets-move-too-fast/

Maybe we need to have this solution as option hardcoded somehow in Armory?

#4

Still fighting with tunelling… Made some setup improving things but tunelling still happens (significantly less often)

Some things here are still opened for tweaks.

here you can see how it works in sketch of golf game:
http://pswida.pl/obrazki-forum/golf/index.html

#5

Here is .blend file to test tunelling, without nodes ball disappears quite fast - after one or 2 impulses. With this nodes setup its better but still some strange behaviour appears. Maybe someone can find solution.antitunelling.blend (795.7 KB)

#6

as you seem to use a simple parabolic trajectory (without disturbing factors like wind, slice/fade, etc…) and your surfaces are simple, determining the point of impact on the ground seems easy and can be enough to define the final point of the ball trajectory upon hitting without using Armory physics if deficient. A specialized math node could be sufficient to do the job.

#7

I thought physics engine is enough specialized for that kind of movements
Yeah, I understand what you mean Didier, for snooker game or just canon shooter this simple math model could be enough but I would like to have more fancy movement finally. I like this small bouncing of ball on the end, bit random effect of rolling, and so on. And for sure wind is an option.