Node Builder

Typically included with map builders (such as Doom Builder 64), the node builder compiles extra lumps which improve engine speed during gameplay. These are the NODES, SEGS, SSECTORS, REJECT, BLOCKMAP, and LEAFS lumps. These lumps save on processing as they pre-calculate values used for rendering (binary space partitioning) and gameplay logic. The default nodebuilder which comes with Doom Builder 64 is called D64BSP, which additionally renders the LEAFS lump (from GLBSP) that aids in polygon rendering and is required for Doom 64.

DMA-BSP64

DMA-BSP64 is an iteration of D64BSP which takes inspiration from ZokumBSP's ability to manipulate the BLOCKMAP and reduce sidedef quantity.

The BLOCKMAP is used for collision detection during gameplay and for many Doom 64 engines it is limited to 65534 bytes in size. DMA-BSP64 allows the mapper to exclude chosen linedefs from BLOCKMAP calculations, allowing for larger than typical maps, and some other mapping techniques, on these engines. It has also been observed some speed increases as well as BLOCKMAP calculations are reduced.

Each linedef of a map references a sidedef. Sidedefs are limited to 65535 in quantity, although this limit is not often reached. These contain information on the textures used, their offset, and the sector in which the sidedef faces. Not all linedefs have unique texture references and offsets, thus not every linedef needs a unique sidedef. As a post-process, the nodebuilder can reduce the number of sidedefs by having identical sidedefs reduced to a single sidedef. Then all of the linedefs are updated to point to this one. This can reduce map size automatically without any change in visuals and behavior.

Installation

First download DMA-BSP64 from its github page. Then extract the contents and put the ".cfg" and ".exe" files in the Doom Builder 64 node builders folder: for example "Doom Builder 64\Compilers\Nodebuilders". Now open Doom Builder 64 and in the "Tools" menu open "Game Configurations". Select the engine of your choice and then go to the "Nodebuilder" tab. Here you will have a few options. You can select "dma-bsp64 - Normal" for both the saving and testing configurations which does not have linedef compression. Or you can select "dma-bsp64 - Pack Sidedefs" to automatically perform sidedef compression.

After clicking "OK", this will allow you to use advanced blockmap techniques to optimize your maps as described in the following section.

Blockmap Optimization

There are two ways to signify lines to be excluded from the BLOCKMAP. The first method is to enable both the "Never Show on Automap" and "Always Show on Automap" flag on the linedef. The "Never Show on Automap" flag takes precedence, so this linedef will be excluded from both the BLOCKMAP and the automap. The second method is to use the tags between 32768 and 65535 (the "negative" tags) on the linedef, which will also exclude the linedef from the BLOCKMAP but it will still appear on the automap (and can be targeted by macros).

Linedefs excluded from the BLOCKMAP will not have collisions and cannot activate actions via thing crossing. For linedefs that separate sectors of equal heights (or small height differences), no collisions are required so they can be safely excluded from the BLOCKMAP. If linedefs on the edge of the map are excluded, things and the player can exit the normal playable area. Interestingly, this technique also allows monsters to ignore high ledges, allowing them to fall off of them. However, this also allows the player to partially clip into ledges, so a second smaller ledge (also excluded from the BLOCKMAP) can be used to prevent the player from getting too close to the higher ledge.