The nodeviewer lets you visually inspect how the nodes were created. For HEXEN, it is important that you check to see that NO lines split an area that has a PolyObject inside of it. A simple example is a square rectangle. The square should be surround by blue/red lines, with no line anywhere inside of it.
You can correct node problems by trying to align areas in line-of sight to share the same X or Y plane and by trial-and-error moving stuff around or adding junk. Junk has nothing with the level, but it can fool the nodebuilder. Refer to MAP01 of HEXEN to see the junk around the sliding doors.
Also try the various Node building options. See the F5 screen and press F1 for more information.
NumPad4 Move to left Node
NumPad6 Move to right Node
NumPad8 Move up a Node
NumPad2 Move down a Node
(* numlock has to be on for above)
C Clear map
E Erase each node
G Toggle node lines
J Jump to node
N Toggle show nodes
S Toggle segment lines
+ - Change Map size (Use C to clear)
Cursorkeys Move Map
If you press F1 after the first help screen displayed, DeePsea displays the following statistics about the nodes:
Pct Balance :This number is from 1 to 100. It is calculated by taking the sum of NodesLeft/NodesRight for each leaf.
So if there were exactly as many nodes on the left as on the right the number would be 100 Pct. The final subsector is not counted. WARM does count this and BSPINFO (we think) does not count this. You could argue either way:)
This number is usually between 60-70 percent. Higher percentages tend to more favorable, taken in context with the Avg. Depth.
Avg Depth :The average number of nodes required for the map. The lower the number, the less calculations required to reach any point on the map.
Max Depth :The greatest depth encountered in the node tree. Sometimes this is an an area the player never reaches, so it does not necessarily reflect the play area of the level.
Pct Left Side : The percentage of the nodes that are on the left side.
Pct RightSide: The percentage of the nodes that are on the right side.
Seg Splits :The number of extra segments added to make the node tree. This number is not too big a deal.
Node Diagonals: The number of node lines that are at an angle. This is directly related to the number of diagonal lines in the level. Diagonals take slightly longer to draw, so fewer is better.
The Pct Left/Right reflect how well the first node was chosen. For large levels, a 50/50 mix is better than a lopsided one. The smaller side would be slightly faster and the larger side plays somewhat slower.
These numbers give an overall flavor of the nodes, but are not meant as absolute standards by any means. In our opinion, the greatest influence on speed (and then only for large levels), is the Avg Depth. The primary criteria is always that the level works.
HEXEN polyobjects can give some trouble in nodes splitting the area where they reside. Polyobjects should always reside in their own sector,preferably rectangular and not at an angle. You can redraw or move the area around, try a different depth value, try setting the node split option, or try a different nodes builder. Just be prepared to spend some time in this area, it's not simple to fix. DeePBSP automatically tries to prevent splits in sectors containing a polyobject!
There is no attempt made to assign a single number to the above. Assigning a number is somewhat meaningless, somewhat like assigning a rating to a PWAD by counting lines and enemies.