FVector UKismetMathLibrary::LessLess_VectorRotator(FVector A, FRotator B)
{
return B.UnrotateVector(A);
}
static void CalcBoundingSphyl(const FRawMesh& RawMesh, FSphere& sphere, float& length, FRotator& rotation, FVector& LimitVec)
{
if (RawMesh.VertexPositions.Num() == 0)
return;
FVector Center, Extents;
CalcBoundingBox(RawMesh, Center, Extents, LimitVec);
// @todo sphere.Center could perhaps be adjusted to best fit if model is non-symmetric on it's longest axis
sphere.Center = Center;
// Work out best axis aligned orientation (longest side)
float Extent = Extents.GetMax();
if (Extent == Extents.X)
{
rotation = FRotator(90.f, 0.f, 0.f);
Extents.X = 0.0f;
}
else if (Extent == Extents.Y)
{
rotation = FRotator(0.f, 0.f, 90.f);
Extents.Y = 0.0f;
}
else
{
rotation = FRotator(0.f, 0.f, 0.f);
Extents.Z = 0.0f;
}
// Cleared the largest axis above, remaining determines the radius
float r = Extents.GetMax();
float r2 = FMath::Square(r);
// Now check each point lies within this the radius. If not - expand it a bit.
for (uint32 i = 0; i<(uint32)RawMesh.VertexPositions.Num(); i++)
{
FVector cToP = (RawMesh.VertexPositions[i] * LimitVec) - sphere.Center;
cToP = rotation.UnrotateVector(cToP);
const float pr2 = cToP.SizeSquared2D(); // Ignore Z here...
// If this point is outside our current bounding sphere's radius
if (pr2 > r2)
{
// ..expand radius just enough to include this point.
const float pr = FMath::Sqrt(pr2);
r = 0.5f * (r + pr);
r2 = FMath::Square(r);
}
}
// The length is the longest side minus the radius.
float hl = FMath::Max(0.0f, Extent - r);
// Now check each point lies within the length. If not - expand it a bit.
for (uint32 i = 0; i<(uint32)RawMesh.VertexPositions.Num(); i++)
{
FVector cToP = (RawMesh.VertexPositions[i] * LimitVec) - sphere.Center;
cToP = rotation.UnrotateVector(cToP);
// If this point is outside our current bounding sphyl's length
if (FMath::Abs(cToP.Z) > hl)
{
const bool bFlip = (cToP.Z < 0.f ? true : false);
const FVector cOrigin(0.f, 0.f, (bFlip ? -hl : hl));
const float pr2 = (cOrigin - cToP).SizeSquared();
// If this point is outside our current bounding sphyl's radius
if (pr2 > r2)
{
FVector cPoint;
FMath::SphereDistToLine(cOrigin, r, cToP, (bFlip ? FVector(0.f, 0.f, 1.f) : FVector(0.f, 0.f, -1.f)), cPoint);
// Don't accept zero as a valid diff when we know it's outside the sphere (saves needless retest on further iterations of like points)
hl += FMath::Max(FMath::Abs(cToP.Z - cPoint.Z), 1.e-6f);
}
}
}
sphere.W = r;
length = hl * 2.0f;
}