Gaia Sky

This is a bug-fix release. It restores the occlusion of the procedurally generated galaxy channels by the volume dust, and fixes several issues that surfaced when creating galaxies from the UI and when inserting entities into the scene graph.

• Half-resolution channels are occluded by full-resolution occluders again.
• Runtime-created billboards bind their texture array correctly.
• Galaxies added via the UI get their parent populated correctly again.
• Fix the guard in the code that adds children to nodes, which made it function improperly. This prevents a crash with the NASA Exoplanet Archive dataset.
• Always run the volume depth pre-pass at full resolution, so that its depth occludes half-resolution content, and skip the full-to-half depth blit when the half-resolution pass is empty.