Wheeled Vehicle Physics Issues


maybe you are aware of an ongoing discussion here forum thread

basically there are (still) major issues with the wheels, i have uploaded a test project here dowload link

this project demonstrates cars being launched into the air from collisions with the wheels, car on car here but it can also occur from geometry collisions, eg curbs.
also there is a speeding car that demonstrates immovable stationary cars.

please press play and watch several times as the results are inconsistent!
(which actually should be a bug report in itself)

thank you

here is my

just another video with physics in unreal(UE4) - YouTube


PS also in your test project vehicles more stable than in my, because in your test project all vehicles have sphere on wheels(so wheels cant directly touch any others objects), but i DON’T want use this spheres because they stack with world objects, i see only one method for fix my problem that create colider mesh(like sphere but with same form like wheel mesh geometry and some how attach it to vehicle bone, but current version of physics asset tool cant do that!!) that can do same job like sphere does, this can fix at vehicle fly(from other objects) problems

hello? anybody there? is it even being looked at or just completely ignored? hello?

Hello tegleg,

Thank you for reporting this issue and providing a project that showcases this problem thoroughly. I’ve placed a bug report in for this issue under the number UE-21990. I’ll be sure to update you here when any updates occur.

As for the response time, please be aware that while we attempt to answer questions in a timely fashion, that we do not work on the weekend.

Have a nice day!

thanks mathew. sorry for the tone of the last comment, its just ive been pushing for this to be fixed since rocket.

Can we now when is this going to be fixed?

Hello ,

Unfortunately we are unaware of when it’ll be fixed as of yet as this is a fix that will be coming from Nvidia rather than us directly as the issues lie in the PhysX vehicles’ implementation. As previously stated, I’ll be sure to update here as soon as we know.

Ok thanks, I just wanted to know.

nice to hear it confirmed the problems are in the physx sdk. there is a new community effort to fix it here link text. its relatively easy to find the faulty piece of code, another matter entirely to fix it though. fingers crossed.

Sorry to enter this old topic, but the issue still seems to be arround.
However, the Issue UE-21990 is marked as a Duplicate, while the (at least to the developers notes) original issue UE-19250 can not be found…

Is this something, that will be resolved one day?

Hello Syrill,

Thank you for bringing this up. I’ve taken a look and the reason the other bug doesn’t seem to exist is because it’s actually a JIRA representation of one of our Github pull requests from Nvidia. We don’t make those public for the public tracker so it doesn’t show up there.

The other report is “Closed” meaning that the changes made by that pull request were implemented in 4.14. Since they obviously didn’t fix the issues expressed by this bug report, I’ve reopened UE-21990 for further investigation. Please continue to track this issue there.

Hey, Matt.

Any news on UE-21990? It seems to have been backlogged for almost 2 years now.


Hello ,

The bug report was marked as a Duplicate for a long time, until February of this year. After noticing that it was still occurring after the issue that it was marked as a Duplicate of was fixed, thanks to Syrill, I reopened it and then it was marked as Backlogged. Vehicle physics fixes tend to come in batches and are fairly far in between so it may be a while until this is fixed.

Wow im bumping this as its still an issue , well mainly when colliding with another vehicle the ■■■■ car flys in the air, similar to when all physics bodies collide with each other in phat editor. but that isnt my case, only when i crash into another vehicle the car flys into the air erradically. any fix for this come on.

Wheel physics are low priority. You can check out Blueman’s vehicle physics on the Marketplace or create your own implementation.

Yeah it seem’s like functionality = low priority and New Buggy features= High priority. Anyway trying to make my own vehicle but ue4 in custom source is becoming a pain with visual studios and i cant derive it’s just not working for me.

the wheel bug is in physx itself so epic will never fix it.
if you want a starter code for your own vehicle there is this

it does not have any issues with wheel collision