Mesh based source + domain rejection

[giovanni-mariano]

I am experimenting the new feature in the develop branch to create mesh based particle sources. I want to report that (at least to my understanding) the domain rejection feature should not be used with them: indeed, the particles are rejected on the basis of the position (or material/universe) sampled in SourceSite IndependentSource::sample

openmc/src/source.cpp

Line 189 in 4116566

p.r() = space_->sample(seed);

However, the actual position is sampled in SourceSite MeshSource::sample

openmc/src/source.cpp

Line 436 in 4116566

// Replace spatial position with the one already sampled

So, in general the two sampled positions are different and the domain rejection should not be used, right? In case, a warning message could be useful.

Thanks Giovanni

[pshriwise]

Thanks for reporting this @giovanni-mariano. You're right, particles are being rejected based on the source site position provided by IndependentSource. I think we overlooked that after a redesign in #2759 to allow use of arbitrary source types in the mesh elements. I'll look into correcting this early in the new year.