Boost/add speed to an actor

[Byakuya]

Hello everyone,

I’m new with Unreal and i’m working on a project in Unreal Engine 5 where I have a sphere that’s supposed to bounce and gain speed with each collision against a surface. I’ve run into an issue where despite my Blueprint being configured correctly, the ball does not increase in speed after bounces.

Here’s what I’ve set up and the steps I’ve followed:

1. I have an On Component Hit node connected to a series of nodes that calculate a reflection vector and apply an impulse to the sphere.
2. I’m using Get Velocity to capture the current velocity of the sphere, which I then feed into Get Reflection Vector to compute the reflection vector.
3. There’s a Vector Length node followed by a Float + Float node to increase the speed’s magnitude before multiplying it with the normalized reflection vector.
4. Finally, I apply this new speed to the sphere with Add Impulse. The “Vel Change” checkbox is ticked, which should apply the impulse as a direct change in velocity.

Regarding collision configuration, I’ve ensured the following:

• The sphere has Simulate Physics enabled, and the collision preset is set to BlockAllDynamic.
• Generate Hit Events is checked on the sphere’s collision component.
• The sphere has a physical material with restitution set to 1.0 and friction to 0.0.
• Collision events appear to trigger correctly, as confirmed by Print String nodes displaying messages upon collisions.

I’m a bit stuck and would really appreciate any help or suggestions you might have

Thank you in advance for your time and assistance.

This is my BP, my sphere confifg and material :

(My ball bounces but doesn’t pick up speed. I’d like it to pick up speed in the direction of the bounce.)

[Majj_1089]

Hi @Byakuya
You can also use Print Text node to show Impulse’s value when collision events appear.

And I got this:

I did the same thing with other values, and fould Get Velocity node returning 0,0,0. That’s why the ball didn’t pick up speed. So you should not Get Velocity from Other Actor.

Take good use of Print Text Node, and I find just doing like this is fine:

[Byakuya]

Hi ! It was exactly what I was looking for, thank you very much!