Doomsday Engine

I've done some investigation into this problem and it appears this is merely a symptom of larger problem which as yet I've been unable to resolve.

How to recreate:
Start jHexen, MAP01
Open the console and enter:
spawnmobj SORCBOSS -2867 -552 floor; god; makecam 0;
move the player to open area in the south west corner of the map where the polyobjects are in the archived map. In this area should now be Heresiarch.

Now, position the player between the Heresiarch and either the north>south or south>north linedefs on the east or west of this area. You should notice that depending on where the player is in this area and the view angle difference between this linedefs will determine whether the mana cubes are visible or not.

The mana cubes are being clipped as a result of drawing the linedef behind the camera C_AddViewRelSeg in rend_main.c: Rend_RenderSubsector

This would indicate that the test in Rend_MarkSegsFacingFront is determining incorrectly that the segs of this linedef are front facing.

I was incorrect in my earlier comment, it is not the segs of the linedef behind the viewer causing these sprites to be clipped. The problem appears to be caused by the ranges added for segs either in the same subsector or further up the BSP tree.

The reason why only the cubes are occluded yet the spinning balls are not continues to allude me.

The reason the cubes are occluded but the spinning balls and the Heresiarch itself are not is because they are in fact linked to entirely different subsectors!

Fixed for 1.9.0-beta6.8

The problem was that after spawning the cubes their position was never again set. Therefore they were still linked to the sector in which they had spawned.

I'm currently looking for any other instances of a similar nature...

I meant "couldn't" instead of "could" above.