_{Half-Life engine map compile tools, based on Vluzacn's ZHLT v34 with code contributions from various contributors. Based on Valve's version, modified with permission.}

New features include shadows from studiomodels, new entities, additional tool textures, ability to extend world size limits, portal file optimisation for J.A.C.K. map editor and minor algorithm optimization.

1. Open the configuration dialog of your map editor or batch compiler.
2. Set CSG, BSP, VIS, RAD tool paths to sdHLCSG.exe, sdHLBSP.exe, sdHLVIS.exe, sdHLRAD.exe, use the _x64.exe editions if running on 64-bit.
3. Add sdhlt.wad into your wad list. This is required to compile maps.
4. Add sdhlt.fgd into your fgd list.

The main benefit of the 64-bit version is no memory allocation failures, because the 64-bit tools have access to more than 2GB of system memory.

Entities with a model keyvalue, such as env_sprite or cycler_sprite, support the use of zhlt_studioshadow 1 to flag the studiomodel as opaque to lighting. Additionally, zhlt_shadowmode n is used to control the shadow tracing mode.
The default 1 will trace for each triangle and supports transparent textures.
Setting 2 doesn't support transparency, but it traces the planes bbox for each triangle, the slowest but usually higher quality for some models.
Setting 0 disables tracing and uses the mesh bbox instead.

To implement these into your own fgd file for SmartEdit, use the template at the top of sdhlt.fgd. If the new shadow covers the origin and makes it too dark, set a custom light_origin on the entity or move the mesh origin point externally.

• info_portal and info_leaf ared used to create a portal from the leaf the info_portal is inside, to the selected leaf the info_leaf is inside. Forces target leaf to be visible from the current one, making all entities visible.
• info_minlights used to set minlights for textures, works on world geometry too. Works similarly to _minlight but per-texture.

• Support for % texture flag, sets the minlight for this texture. %texname alone is equivalent to _minlight 1.0, while %#texname where # is an integer in a range of 0-255.
• BEVELHINT texture, which acts like SOLIDHINT and BEVEL. Eliminates unnecessary face subdivision and bevels clipnodes at the same time. Useful on complex shapes such as terrain, spiral staircase clipping, etc.
• SPLITFACE texture. Brushes with this texture will subdivide faces they touch along their edges, similarly to zhlt_chopdown.
• cur_tool textures, which act like CONTENTWATER and func_pushable with a speed of 2048 units/s in -Y. This texture is always fullbright.

• -pre25 RAD parameter overrides light clipping threshold limiter to 188. Use this when creating maps for the legacy pre-25th anniversary engine without worrying about other parameters.
• -extra RAD parameter now sets -bounce 12 for a higher quality of lighting simulation.
• -worldextent n CSG parameter. Extends map geometry limits beyond +/-32768.
• Portal file reformatting for J.A.C.K. map editor, allows for importing the prt file into the editor directly after VIS. Use -nofixprt VIS parameter to disable.
• -nowadautodetect CSG parameter. Wadautodetect is now true by default regardless of settings.
• -nostudioshadow RAD parameter to ignore zhlt_studioshadow on studiomodels.

• BLOCKLIGHT texture, cast shadows without generating faces or cliphulls.
• Optimization for BuildFacelights and LeafThread
• Res file creation for servers
• Split concerns into their own libraries instead of repeating infrastructure and util code
• Full tool texture documentation