Get vector length in a float declaration?

Development Programming & Scripting C++
1

Is it possible to get the length of a vector while declaring the variable in a function? If so, what’s the terminology/jargon to do it? This is an engine source change but nobody ****** posts or replies in that part of the forums so I’m dropping it here…

Here’s my code, what I want to do is get the length of the hard-coded (Particle.Velocity) vector and store it as “VelocLength” like so:



void UParticleModuleSizeByVelocity::Update(FParticleEmitterInstance* Owner, int32 Offset, float DeltaTime)
{
	BEGIN_UPDATE_LOOP;
	/* Get the length of the particles velocity vector */
	float VelocLength = ;


	FVector VelocityScaleFactor = SizeByVelocity.GetValue(Particle.RelativeTime, Owner->Component) * (Particle.Velocity);
	Particle.Size = Particle.BaseSize * VelocityScaleFactor;
	END_UPDATE_LOOP;
}

I’ll then modify the code to change the velocity scale factor by the vector length, just like the following:



void UParticleModuleSizeByVelocity::Update(FParticleEmitterInstance* Owner, int32 Offset, float DeltaTime)
{
	BEGIN_UPDATE_LOOP;
	/* Get the length of the particles velocity vector */
	float VelocLength = BLAHBLAHBLAH;
	float VelocityScaleFactor = SizeByVelocity.GetValue(Particle.RelativeTime, Owner->Component) * VelocLength;
	Particle.Size = Particle.BaseSize * VelocityScaleFactor;
	END_UPDATE_LOOP;
}

This is done every-frame per particle, so it can’t be TOO computationally expensive. Surely there’s a short-cut way to do it? Oh and of course, the float should be an absolute (positive) value too.

2

Okay, turns out the way to do it isn’t Size(Particle.Velocity), but instead use Particle.Velocity.Size()