If you already know the distance and the rotation, you can do something like this:
This function will return the final location for the mesh. Also, you should set the mesh’s rotation to the same rotation used in this function.
How can I rotate a mesh around an arbitrary point in space?
For example a moon rotating around a planet.
Thanks
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Perfect. Thanks!!
Would be possible to create a blueprint function that generates an ellipse movement around an arbitrary point in space. A function that we could input the center point position + the two ellipse focus points positions (that will define the ellipse shape). Is there a way to do it?
Here is my solution to it. It will rotate the object around the given Pivot using the objects own rotation. E.g. A delta rotation around Z will rotate around the objects Z axis. Optionally you can retain the rotation of the object itself.
You can write this as a function, for sure.
UFUNCTION(BlueprintPure)
static void RotateAroundPivot(const FTransform& Original, const FVector PivotLocation, const FRotator DeltaRotation, bool bRetainOrientation, FTransform& New)
{
FTransform PivotTransform = FTransform(Original.GetRotation(), PivotLocation);
FTransform DeltaPivotToOriginal = Original * PivotTransform.Inverse();
New = FTransform(DeltaRotation.GetInverse() * (float)bRetainOrientation, FVector(0,0,0)) * DeltaPivotToOriginal * FTransform(DeltaRotation, FVector(0,0,0)) * PivotTransform;
}
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This works regardless of the initial orientation as it doesn’t require the forward vector and has solved my issue of rotating a parent actor around a child actor. I’ve been struggling with this for hours. Thank you so much!
I found a good way to do this was to do something like this:
FVector pointLocation = ...
FVector thingYouRotatePosition = ...
float amountYouWantToRotate = ... //(0-2pi)
// make a Quaternion with an upward axis (rotating around the upwards axis)
FQuat rotation = FQuat(FVector::UpVector, amountYouWantToRotate);
// get the offset of you the thing you are rotating, from the point
FVector offset = pointLocation - thingYouRotatePosition;
// rotate it and add that to the point location
FVector newRotation = rotation.RotateVector(offset) + pointLocation;
Quaternions are really handy once you learn how to use them. Though most of the explanations I’ve seen seem a little complicated.
How they work is that you give them a vector that tells it what to rotate around, and then you tell it how much to rotate around that ‘axis’. So if you give it a vector that points straight up, it’ll rotate around that like I did above.
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