Engine Hunk Overflow

What Does It Mean?

Engine Error

This is an engine error message that occurs when attempting to load the map in-game. This is due to too much lightmap data being allocated for the level, and it exceeds the budgeted memory for lightmaps (the "hunk").

Note:This error is fixed in and , as they removed the hunk allocator and therefore have no limit. disabled the hunk by default so this error will not happen there either.

What Is Hunk Allocation

This is described as the memory allocated for lightmap data.

• 0 = to normal "program memory" with alloc
• 1 = to Valve's seemingly limited to certain size "MemoryStack memory" with Hunk_Alloc

Methods To Fixing The Error

• +r_hunkalloclightmaps 0
  • Add this in your launch options. This will eliminate the error altogether. While fine for singleplayer games, it is not recommended for multiplayer games, as not only will you have to add this to your launch options, but server operators will also have to add it to their server command line.
    
• Find faces with odd or extreme lightmap values.
  • Very large displacements can cause this error. The lightmap value can automatically change (sometimes, to an undesired value). Split them up and/or make sure your lightmap is an even value of a power of 2, avoiding extreme numbers. Having stretched displacements in one dimension can also cause it.
  • If you can't find any odd lightmap values, as a last resort, select the entire map, open the Face Edit Sheet and input 16 for the lightmap scale.
  • Increasing the Lightmap value on brushes will fix it.