See Javadoc of Matrix3f
and Javadoc of Matrix4f

A Matrix is typically used as a linear transformation to map vectors to vectors. That is: Y = MX where X is a Vector and M is a Matrix applying any or all transformations (scale, rotate, translate).

There are a few special matrices:

zero matrix is the Matrix with all zero entries.

The Identity Matrix is the matrix with 1 on the diagonal entries and 0 for all other entries.

A Matrix is invertible if there is a matrix M^-1 where MM^-1 = M^-1 = I.

The transpose of a matrix M = [m_ij] is M^T = [m_ji]. This causes the rows of M to become the columns of M^T.

A Matrix is symmetric if M = M^T.

Where X, A, B, and C equal numbers

jME includes two types of Matrix classes: Matrix3f and Matrix4f. Matrix3f is a 3×3 matrix and is the most commonly used (able to handle scaling and rotating), while Matrix4f is a 4×4 matrix that can also handle translation.

Multiplying a Vector with a Matrix allows the Vector to be transformed. Either rotating, scaling or translating that Vector.

If a diagonal Matrix, defined by D = [d_ij] and d_ij = 0 for i != j, has all positive entries it is a scaling matrix. If d_i is greater than 1 then the resulting Vector will grow, while if d_i is less than 1 it will shrink.

A rotation matrix requires that the transpose and inverse are the same matrix (R^-1 = R^T). The rotation matrix R can then be calculated as: R = I + (sin(angle)) S + (1 - cos(angle)S² where S is:

Translation requires a 4×4 matrix, where the Vector (x,y,z) is mapped to (x,y,z,1) for multiplication. The Translation Matrix is then defined as:

where M is the 3×3 matrix (containing any rotation/scale information), T is the translation Vector and S^T is the transpose Vector of T. 1 is just a constant.

Both Matrix3f and Matrix4f store their values as floats and are publicly available as (m00, m01, m02, …, mNN) where N is either 2 or 3.

Most methods are straight forward, and I will leave documentation to the Javadoc.

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