Affine transformation

Applies an affine transformation to the particle positions and/or the simulation cell. The transformation is either specified as a 3x3 matrix and an additional translation vector or by prescribing a target simulation cell to which the particles are mapped.

Given the 3x3 transformation matrix M and the translation vector t, the new position x' of a particle at the old position x is computed as x' = Mx + t. Vectors are column vectors in this notation.

The Enter rotation button opens a utility that lets you enter a rotation axis and an angle. It computes the corresponding transformation matrix for you.

Parameters

Transform simulation cell

Selects whether the transformation is applied to the simulation cell.

Transform particles

Selects whether the transformation is applied to the particle coordinates. You can select which particles are affected by the modifier: All particles or only the selected ones.

Transform surface mesh

Selects whether the transformation is applied to the surface mesh (if one exists). Surface meshes are typically created with the Construct surface mesh modifier.

Transformation matrix - Rotate/Scale/Shear

The 3x3 matrix specifying the affine transformation.

Transformation matrix - Translation

The translation that is added after multiplying a particle position with the matrix.

Transform to target box

The three vectors that define the target simulation cell. The modifier will automatically calculate the transformation matrix based on this target cell shape and the input simulation cell.