Wheeled Vehicle - Trouble Getting Input to Work

I’ve spent some time trying to get a simple wheeled vehicle to work, but no matter what I try I can’t seem to get it to accept any keyboard input. The physics seems fine - dropping the vehicle onto a ramp, the wheels spin and bounce as expected and the vehicles moves over the surface. There must be something simple I’m missing. Has anyone had a similar problem, and if so what did you do to fix it?

Some details:

  1. I’ve tried following the tutorials in the documentation ( , , I’ve gone through the instructions on these pages several times in case I missed anything, and have tried adding a vehicle to both a blank project and a project with content, with the same results in all cases. In order to get the physics of the wheels to work properly, I had to put in additional offsets in the Vehicle Blueprint. This isn’t in the User Guide - though looking at forums/tutorials it does seem to be a common necessity.

  2. I’m using Unreal 4.20.1 and Blender 2.79b. I’ve tried following a couple of Blender-specific tutorials step-by-step (e.g. and get the same result as with my custom vehicle, both when trying to add a vehicle to a new project and when starting with content.

  3. The axis and action mappings are set up as in the Vehicle Blueprint Starter Project. I know that the Vehicle Blueprint is doing something during PIE as I have an Execute Console Command node connected to event begin play, which is using the command “pxvis collision 1” to show the collision shapes for the wheels. The only action I have is Handbrake (spacebar); the only axis mappings are MoveForward (W and S keys) and MoveRight (A and D keys). The Event Graph has a Set Throttle Input, Set Steering Input and Set Handbrake Input.

(4. The execution flow panel in the blueprint debugger has, under execution trace, lots of lines like “(unknown) (object no longer exists)@2,414.06s”. I don’t know much about debugging - is this telling me something useful?)

In short, during PIE I press buttons and nothing happens, the vehicle just sits there. Does anyone have any ideas?

Problem solved. I forget to click in the PIE window before pressing buttons. For two days. D’oh!