Transformations

Transformations can be applied in LUMA through either the CLI flags or through the parameter file.

They are applied in a specific order and CLI flags will override the parameter file settings.

Coordinate System

• X-axis: Left-right (positive = right)
• Y-axis: Anterior-posterior (positive = anterior/forward)
• Z-axis: Superior-inferior (positive = superior/up)
• Rotations: Right-hand rule (positive = counterclockwise)

Transformation Order

1. Rotation first: Applied around origin (X, then Y, then Z axes)
2. Translation second: Applied after rotation

Usage Examples

Command Line (Priority):

# Rotate 180° around X, translate 10mm in Z
luma -p params.toml -c ct.vtk -m mesh.cdb --rot 180.0 0.0 0.0 --trans 0.0 0.0 10.0

Parameter File:

[mesh_transformation]
mesh_rotate_x = 180.0
mesh_translate_z = 10.0

Common Use Cases

• Flip mesh upside down: --rot 180.0 0.0 0.0
• Rotate around vertical axis: --rot 0.0 0.0 90.0
• Align with CT coordinate system: --trans -50.0 -30.0 -100.0