Train rework due to physics update

I’m the developer of a popular train game which had to close once the new physics system came out just after Christmas (Named CSG I believe?).

What do I need to do to migrate my train chassis so that it is supported within the current physics engine?

It runs the NX Transit chassis.


Have no clue what that is. Can’t really expect people to know what you’re talking about off the fly. Please provide more information and/or resources so we can more appropriately answer your question.


I think CSG is solid modelling (Unions and negates, that stuff). While I don’t have much experience with chassis systems, maybe you could go more into depth about the problems the new physics system is giving you? Oftentimes in my (limited) experience physics issues can be fixed in advanced game settings or minor script changes can resolve the issue. What exactly happens to the trains when you boot the game? Is it as simple as they don’t function at all?

As far as I’m aware, CSG stands for constructive solid geometry, which is related to unions and negations for building things in Roblox Studio.

I believe that Roblox is currently using PGS (Projected Gauss-Seidel) solver for the physics. Previously, Roblox has used the Spring Physics solver, and here’s an article about it - Physics: Deprecating the legacy spring physics solver.

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They perform very poorly, reaches top speed of about 3 then will come to a complete halt. Before the physics implementation they were a pleasure to drive with a top speed of 150.

We can arrange a demonstration ingame if you wish? I have had the game closed since Christmas as a result.


Im2606 - can you please post a simplified model of your train so we can investigate and provide some suggestions to improve it?


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I don’t really think I’m experienced enough to be worth arranging a full consultation. My only real recommendation would be to experiment with the physics settings in Studio to see if you could make something work more efficiently.

Definetely do this if my recommendations fall flat.

You probably just have to mess around with the torque and maybe part density/friction settings?

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