Understanding Propagation Errors

This page describes the different types of propagation errors that can be encountered during a simulation.

Volume body not closed error

Volume body not closed error occurs when a ray inside a solid body cannot hit a face of this given solid (to go out of this solid), only rays located really close to a corner can be involved. This error can occur either if the solid faces are not really closed (imported geometry) or if a ray cannot detect a face due to the geometrical optical precision. This error can occur especially when VOP on Surface parameter is used. This error can occur if using a geometry thinner than the minimal distance tolerance.

This error can be reduced by improving the precision of the CAD geometry or reducing the geometrical optical precision.

You can also calibrate the propagation parameters and the meshing parameters to reduce the error percentage.

Volume conflict error

Volume conflict error occurs when a photon inside a body hits another solid body. This error can occur especially when VOP on Surface parameter is used.

Note: This propagation error should be corrected by changing the geometry modeling.

Propagation Errors on Corners of 3D geometries

In case of reflection of rays near an angle of a 3D geometry (geometry with corners an edges such as cube, rectangle, prisms, etc.), the next intersection with the geometry could be missed due to a too high geometrical distance tolerance.

Try reducing the Geometrical Distance Tolerance to be as close as possible to the angle.

2D tangency error

2D tangency error occurs when a solid geometry and surface geometry, or a surface geometry and another surface geometry are tangent in a same simulation.

Note: Speos can manage two tangent solid geometries in a same simulation.

Note: This propagation error can be avoided by separating geometric elements by at least geometrical optical precision.

Non optical material error

Non optic material error occurs when a ray enters in a solid body having non optic as volume optical properties.

Note: This propagation error should be corrected by changing the modeling.

Non optical material at emission error

Non optical material at emission error occurs when a ray is directly emitted inside a solid body having non optic as volume optical properties.