How can I rotate a vector to another one, using VEX?

[Masoud]

Hello guys,

Using VEX, how can I rotate a vector to another vector, by a blend value from zero to one (i.e 1=fully aligned, 0= not-aligned)?

Thanks for helping.

[konstantin magnus]

Hi Masoud,

to blend orientations two orthogonal vectors are required for each point: one normal, one up. For this you could use the polyframe node or a cross() product.
maketransform() converts these vectors into a matrix that is to be turned into a quaternion().

matrix3 xform = maketransform(v@up, v@N);
vector4 orient = quaternion(xform);

slerp(), spherical linear interpolation, then blends between both orientations:

float blend = chf('blend');
vector4 orient_1 = point(0, 'orient', 1);
vector4 orient_2 = point(0, 'orient', 2);
p@orient = slerp(orient_1, orient_2, blend);

 

blend_orientations.hiplc

[Masoud]

Hi Konstantin;
Thank you for the reply.

Actually, I want to rotate scattered points' Normal to another direction (i.e. MyVector) using a blend amount.

At first, I tried the lerp() function but instead of rotation, it blends them.

Then I tried:

float angle = chf("Angle");
vector4 rot = quaternion(radians(angle), v@myVector);
v@N = qrotate(rot, @N);

But it rotates the Normal around "My-Vector"!

 

Here is an image of what I need:
 

 

 

Rotate_Vector.hip

Edited December 25, 2021 by Masoud

[Librarian]

@Masoud Maybe it Helps!

vector tips.hiplc

Edited December 25, 2021 by Librarian

[Masoud]

Hi Tesan,

Than you.

Yes, it works fine:

vector4 q1 = quaternion(@N);
vector4 q2 = dihedral(v@N, v@targetVector);
vector4 quat = slerp( q1, q2, chf("bias"));
v@N = qrotate(quat, v@N);

 

[Librarian]

You are welcome @Masoud
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