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Unity Problems with Unreal Engine 4 Project / Wheeled Vehicle Derived Blueprint

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I know what some people will be going to be saying... "You should put that into the official epic forums". Given that place seems to be pretty "unresponsive" when it comes to get answers for your problems (to be fair, the same was true for the official Unity forums), and I gues some people here also use UE4, I'll retry here.


I even put a post into epics forum which is gathering dust for 1.5 weeks now. Nobody seems to be even looking at it.


I currently have a problem in my Unreal Engine 4 project. Here is a description of my problem from the original thread I put up in epics forums:



I have created a Blueprint Class derived from WheeledVehicle to setup a vehicle in my own project.

I have followed all the steps in the Officiel UE4 "Overview and Car Setup" Video (
), but I cannot get it to work.

If I follow all the steps, and also create a new GameMode and assign the WheeledVehicle Blueprint as default pawn, my camera starts to go haywire for a second and then the camera is black (most probably the camera is attracted to the vehicle mesh anddisappears in it?... no matter if the cam is on the spring arm, directly attached to the vehicle or static in the level. Even deleting the cam and relying on the default cam leads to this problem.

Now, I haven't used a GameMode before and I am not sure I actually want to use it... so I removed it. And the camera starts to work again. But the mesh of the pawn is no longer visible.
And after further testing, same Problem as when the Pawn is set as defaultPawn in an active GameMode is actually also happening when "Auto Posess Player" is set to "Player 0". I guess the Mesh is visible now, cannot tell as the screen goes black in seconds.

1) Why is the Mesh not visible when nobody is controlling it? Is that normal behaviour of UE4?
2) Why seems my camera goes haywire, even the default one, when somebody is controlling the pawn?




Since then, I have created a Project from the Car Starterproject that is shipped with UE4. I migrated the whole "Sedan" directory to my own project to test it. I tested the Sedan BP in the original project first just to be sure, works fine there.


In my project the whole same things happens as with my own Blueprint. Cam goes Haywire and then the image is black.


I did create a new level, just basic level without any change, and place the Sedan BP there. Controls are not working, but the Cam at least is not going haywire.


Now, this seems to be a problem with my level. What do other Unreal Engine users recommend as my next steps?

1) Debug the level. But how? Is there any kind of Profiler that would help me in the Editor?

2) Strip the scene of objects and scripts until the car bp works fine again. Given I do not have any debug option, that seems to be the best bet I have on finding the culprit without having to recreate the scene.



As much as I love the results that are achievable with Unreal Engine 4, everything in the editor just feels like some kind of uphill struggle compared to Unity. :-/

Edited by Gian-Reto

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Well, I myself just used the "WheeledVehicle" Blueprint Class as explained in the Youtube Video linked. What the Sedan example Blueprint is using IDK.


Of course, what I really WANT to do is setup the physics manually in the editor and then use C++ to drive and correct the physics component, like what I did in Unity. I can not get my head wrapped around the concept of these blueprint shenigans!


Is there a way to just hook up the physics in the editor, without any blueprint involved, and then use C++ to control the physics? Or is there a way to setup the Physics directly from C++?

If there would be tutorials on that, that would be even better! Kinda hard to find a tutorial that explains the C++ side of the engine, everyone seems to do Blueprints no matter what.

Edited by Gian-Reto

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For each template there is a blueprint and a C++ equivalent. If you use the C++ version a minimum of blueprint is used simply as glue to tie together the C++ classes and if you choose blueprint no C++ is used at all. As a C++ and C# guy perhaps the C++ template is more like what you need?

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For each template there is a blueprint and a C++ equivalent. If you use the C++ version a minimum of blueprint is used simply as glue to tie together the C++ classes and if you choose blueprint no C++ is used at all. As a C++ and C# guy perhaps the C++ template is more like what you need?


I didn't knew there was a C++ version of each template. Yes, I think this would make it easier for me to get into. I really should look into that.


I guess I should also read the whole physics setup part of the engine documentation better. It seems this is just radically different to Unity, and I guess I am trying to take shortcuts here where there are none.

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