Mat4::MakeDir not working?

[SpiderPig]

I'm not positive I'm using it right... but no matter what I do the matrix's rotation (r) is always zero.  Where as (i) is correct - Vec3(0,90,90);  MakeDir() returns nothing, I checked.

auto m = Mat4();
m.MakeDir(Vec3(0,0,1), 1);

up_pivot->AlignToVector(Vec3(0,0,1), 1);

auto i = up_pivot->GetRotation();
auto r = m.GetRotation();

 

[Josh]

Strange...you would expect a lot of problems if these functions were off...

    Mat4 m;
    m.MakeDir(Vec3(0, 0, 1), 1);
    
    Print("Mat4");
    Print(WString(m[0]));
    Print(WString(m[1]));
    Print(WString(m[2]));
    Print(WString(m[3]));

    Print("Quat");
    auto q = m.GetQuaternion();
    Print(WString(q));

    Print("Euler");
    auto r = q.Euler();
    Print(WString(r));

 

[Josh]

Oh, I think I know why. It's pointing straight down, so you activated Gimbal lock.

[Josh]

Use mat.GetQuaternion() to get the exact rotation.

[SpiderPig]

Thankyou.  But should this code give two different results?

auto m = Mat4();
m.MakeDir(Vec3(0.0f, 0.0f, 1.0f), 1);

Print("Mat4");
Print(WString(m[0]));
Print(WString(m[1]));
Print(WString(m[2]));
Print(WString(m[3]));

Print("Quat");
auto q = m.GetQuaternion();
Print(WString(q));

Print("Euler");
auto r = q.Euler();
Print(WString(r));

Print("");
Print("--------------------------------------------------------------");
Print("");

auto up_pivot = CreatePivot(nullptr);
up_pivot->AlignToVector(Vec3(0.0f, 0.0f, 1.0f), 1);

m = up_pivot->GetMatrix();

Print("Mat4");
Print(WString(m[0]));
Print(WString(m[1]));
Print(WString(m[2]));
Print(WString(m[3]));

Print("Quat");
q = m.GetQuaternion();
Print(WString(q));

Print("Euler");
r = q.Euler();
Print(WString(r));

Console Output.

Mat4
1, -0, -0, 0
0, 0, 1, 0
0, 1, 0, 0
0, 0, 0, 1
Quat
-0, -0, 0, 0.707107
Euler
0, -0, -0

--------------------------------------------------------------

Mat4
0, 1, -0, 0
0, 0, 1, 0
1, -0, -0, 0
0, 0, 0, 1
Quat
-0.5, -0.5, -0.5, 0.5
Euler
-0, 90, 90

 

[Josh]

It may. Aligning an object to a vector is an ambiguous operation.

[Josh]

The entity method takes roll into account, and tries to make the best decision. The Mat4 method is simpler.

[SpiderPig]

Oh okay, I thought maybe both did the exact same thing.  How would I align a matrix to a vector?