Very Large Map Performance

I've recently switched from using Risen3D to Doomsday. Previously, I was playing a map called foursite. This map is billed as one of (if not the) largest maps (vertex wise) created to-date for Doom source ports.

Quoted from the readme:
  • Title: Foursite
  • IWAD: Doom 2
  • Source Port required: Anything that supports DeepBSP Extended Nodes. The map has no non-vanilla features beyond its physical size.
  • Tested on: ZDoom, GZDoom, Crispy, Risen3D, PRBoom+, Eternity, Zandronum and Zandronum 3.0.
  • Primary purpose: Single player
  • Content: No new assets, but a DEHACKED file with some small gameplay changes

Under Risen3D, even with the model and texture packs provided on the Risen3D site, the map runs terrific... 230+ fps. Under Doomsday, even with vanilla render mode and no mods at all, the map chugs at ~15fps. Any thoughts on why this is or what I might do to correct it? I strongly suspect this is not a graphics problem.

Comments

  • Here are some thoughts without performing any actual concrete performance measurements.

    Sometime during several of the late 1.x versions, the renderer was being reworked (mainly by DaniJ) for more internal flexibility and future-proofing. However, as an unfortunate side-effect, it became less efficient.

    Granted, large maps have always been challenging for Doomsday's geometry processing.

    I am working on a completely redesigned renderer that uses the GPU to maximum effect, also for handling geometry. It is not ready for release yet, though.

    There may not be much you can do to correct this issue. You could see if using the Vanilla renderer profile helps at all. If so, some of the special effects may be the bottleneck and we could take a closer look in the profiler.
  • The vanilla renderer helps a little (from ~15 fps up to ~25... but it still seems like it may just be something about the shear number of vertices... or perhaps the format the map is stored in). But then I've not looked under the hood... so I defer to you on that.
Sign In or Register to comment.