I only get around 3 FPS when the terrain merged with the instances which are all packed geometries. But when I split the terrain and the instance geometries, set the display flag to the terrain, and set the selectable template flag to the instances, I get an FPS boost to around 20FPS which is acceptable. But when I merge the terrain and instances, I get the low FPS still. So is it a bug or something else I could do to improve the viewport performance? Thank you.
Merge Node is not as innocent as it seems**, as it applies all incoming attributes to all input geometry, so you might end up with unnecessary garbage. Don't know if that is the reason for your slow down, anyway could you separate the two geos into two different geometry objects?
** For example if you combine with a merge node a time-dependent geometry with a non animated geometry, it seems to me that the merge node would force a unnecessary re-cook for every frame of the non-animated geometry as well. This seems to occur in this example file https://www.sidefx.com/forum/topic/59198/#post-265292 [www.sidefx.com]
