Hi there!
I want to implement my own logic when my character steps onto a slope.
I need the angle of the floor below my character, but I don’t know how to retrieve it.
Google for DOT product, it gives you cosine of angle between 2 vectors.
In your case calculate dot product of impact normal and [0,0,1] vector. Then arc cos of it.
Thank you very much it works.
I wasn’t sure about Dot Product, because Dot Product returns an orthogonal vector iirc. What’s an orthogonal vector from 0,0,1 and 0,0,1 (flat surface?)
CROSS returns orthogonal vector. DOT product returns cosine.
sorry to revive an old thread, but i need some help with this topic, tried searching on google but i didn’t figure it out, any help will be very useful.
you need to calculate the Dot Product between the Vector (0,0,1) and your Floor Normal.
Use arccos on this and you get the angle in degrees. (you can omit arccos tho)
thank you, it worked.
Perfect topic! Thank you for your answers so far. I’m trying to implement the same setup with slope angle, but I want to detect if the angle is increasing or decreasing over time? How to store previous angle and compare it with current angle, so I can switch stuff ( like animation, and movement speed, and ground friction ) depending of that if you are going uphill or downhill?
Thank you !
You can take the Z Axis value from your Actor’s Location and compare it with the Z Axis value last frame. If the difference is a +ve value you’re going up and if it’s -ve you’re going down.
Kinda like this
In your tick() function
LocationLastFrame = LocationThisFrame; // Both variables are FVectors defined in Header file
LocationThisFrame = GetActorLocation();
float Difference = LocationThisFrame.Z - LocationLastFrame.Z; // Difference variable contains the value you need
if (Difference > 0.1)
{
// You’re going up
}
else if (Difference < -0.1)
{
// You’re going down
}
I may be forgetting something here but this is the gist of it. Hope it helps :).
How do you get the floor normal? I can’t find a node for “get floor normal” and googling was no help either. Is that a node I’m suppose to have or is there a different thing I use to get the floor normal that is just worded weird (or has it been changed in UE5)
You are replying to a very old post. But here is your answer:
that is from the Character Movement component assigned to character blueprint by default
(floor normal is stored in the hit result struct)
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