How to multiply Matrix with Vector in Halcon?

Question

I am trying to multiply 4x4 transformation matrix with a Point Vector(4x1) in Halcon. Which command should i use since so far i haven't found anything

I tried to multiply with with hom_mat3d_compose and matrix_multiply but nothing so far.

Answer 1

Here are two methods. The first method uses homogenous coordinates. The second method can multiply any 4x4 matrix with a 4x1 matrix.

*Method 1 - affine_trans_point_3d
hom_mat3d_identity (HomMat3DIdentity)
point_vector := [1, 2, 3, 1]
affine_trans_point_3d (HomMat3DIdentity, point_vector[0], point_vector[1], 
point_vector[2], Qx, Qy, Qz)

*Method 2 - Matrix Multiplication
matrix_identity := [1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1]
create_matrix (4, 4, matrix_identity, MatrixIdentity)
matrix_point_vector := [1, 2, 3, 1]
create_matrix (4, 1, matrix_point_vector, MatrixPointVector)
mult_matrix (MatrixIdentity, MatrixPointVector, 'AB', MatrixMultID)