Unreal Engine 5 · Blueprint → C++
Add Impulse in Unreal Engine 5 C++UE Docs
The Add Impulse node maps to UPrimitiveComponent::AddImpulse. Call MyMesh->AddImpulse(FVector(0,0,50000), NAME_None, false); to apply an instant momentum change to a simulating body.
Blueprint node & C++ equivalent
MyMesh->AddImpulse(FVector(0.f, 0.f, 50000.f), NAME_None, /*bVelChange=*/false);What does the Add Impulse node do?
Add Impulse applies an instantaneous change in momentum to a physics body, producing a sudden push, pop or launch. Unlike Add Force, it is applied once rather than accumulated over the frame, so it is ideal for kicks, jumps and explosions felt at a single instant.
In C++ the function is AddImpulse on UPrimitiveComponent, taking the impulse vector, an optional bone name, and a bVelChange flag.
The C++ equivalent
The snippet MyMesh->AddImpulse(FVector(0.f, 0.f, 50000.f), NAME_None, false); pushes the mesh straight up the Z axis. The second argument NAME_None means the impulse is applied to the whole body rather than a named bone on a skeletal mesh.
The third argument, bVelChange, controls how the value is interpreted. When false, the impulse is scaled by the body's mass (heavier objects move less). When true, it is treated as a direct velocity change in cm/s, ignoring mass.
Common mistakes
The component must be simulating physics or AddImpulse does nothing, so call SetSimulatePhysics(true) first. The impulse magnitude is also large because it is in mass-scaled units; with bVelChange=false you often need values in the tens of thousands to visibly move a heavy mesh, exactly as in the example.
Frequently asked questions
What is the difference between AddImpulse and AddForce in UE5?+
AddImpulse applies an instant one-time change in momentum, while AddForce accumulates over the frame and is meant for continuous pushing. Use AddImpulse for sudden hits and AddForce for sustained thrust.
What does bVelChange do in AddImpulse?+
When bVelChange is false, the impulse is divided by the body's mass. When true, it is applied as a direct velocity change ignoring mass, so identical values affect light and heavy bodies the same.