VRAD

An optional compiling tool provided with the Hammer editor, that calculates the lighting of a map. It gives parts of the level, called patches, a certain amount of brightness depending on how much light it would receive. If VRAD is not used, the level will be lit in fullbright mode (no lighting).

Speed

This is the generally the slowest of the three compile stages due to the many, many calculations it must perform. Map optimization can reduce the speed of this tool somewhat, especially reducing the number of unique names given to lights (which reduces the number of dynamic light combinations for which radiosity must be calculated).

If you are watching the compile dialog and it looks like it has hung at 9... this is usually because Vrad takes longer with each light bounce calculation. Be patient.

To speed up VRAD, Win NT/2k/XP/2k3 users can open "Windows Task Manager" (<Ctrl>+<Shift>+<Esc> or <Ctrl>+<Alt>+<Del> on Windows XP or newer) and set the priority of "vrad.exe" higher. But beware, changing its priority will reduce the amount of resources available to the system itself and may cause freezes until the end of the process!

Options

Use these in combination with expert compile mode or a batch file:

Common options

Name	Description and Notes
v (or -verbose)	Turn on verbose output.
-bounce #	Set max number of bounces (default: 10).
-fast	Quick and dirty lighting. (Has been known to leave dark lines around displacments)
-both	Compiles lightmaps for both Low Dynamic Range and High Dynamic Range lighting models. (Cycles twice)
-final	Increases the quality of skylight and indirect light by spending more CPU time firing rays.
-ldr	Turn on verbose output.
--hdr	Compiles only HDR lightmaps.
-low	Run as an idle-priority process.
-rederror	Run as an idle-priority process.
-vproject <directory>	Override the VPROJECT environment variable.
-game <directory>	Same as -vproject.

Other options

Name	Description and Notes
-novconfig	Don't bring up graphical UI on vproject errors.
-dump	Write debugging .txt files.
-dumpnormals	Write normals to debug files.
-threads	Control the number of threads vbsp uses (defaults to the number of processors on your machine, doubled for CPUs with hyperthreading).
-lights <file>	Load a lights file in addition to lights.rad and the level lights file. A file specified must have the .rad extension. IE: lights_exec.rad.
-mpi	Use VMPI to distribute computations.
-noextra	Disable supersampling.
-debugextra	Places debugging data in lightmaps to visualize supersampling.
-smooth #	Set the threshold for smoothing groups, in degrees (default: 45).
-dlightmap	Force direct lighting into different lightmap than radiosity.
-stoponexit	Wait for a keypress on exit.
-mpi_pw <pw>	Use a password to choose a specific set of VMPI workers.
-nodetaillight	Don't light detail props.
-centersamples	Move sample centers.
-luxeldensity #	Rescale all luxels by the specified amount (default: 1.0). Must not exceed 1.
-loghash	Log the sample hash table to samplehash.txt.
-onlydetail	Only light detail props and per-leaf lighting.
-maxdispsamplesize #	Set max displacement sample size (default: 512).
-softsun <n>	Treat the sun as an area light source of size <n> degrees. Produces soft shadows. Recommended values are between 0 and 5. Default is 0.
-FullMinidump	Write large minidumps on crash.
-chop	Smallest number of luxel widths for a bounce patch, used on edges.
-maxchop	Coarsest allowed number of luxel widths for a patch, used in face interiors.
-LargeDispSampleRadius	This can be used if there are splotches of bounced light on terrain. The compile will take longer, but it will gather light across a wider area.
-compressconstant <n>	compress lightmaps whose color variation is less than n units.
-StaticPropLighting	generate backed static prop vertex lighting. (Processor-intensive)
-StaticPropPolys	Perform shadow tests of static props at polygon precision. (Very processor-intensive - default is to use collision models for shadows)
-OnlyStaticProps	Only perform direct static prop lighting (vrad debug option)
-StaticPropNormals	when lighting static props, just show their normal vector
-textureshadows	Generates shadows based on alpha textures. (editing of the lights.rad file is required.)

Lights files

A lights file contains rules for glowing textures and model and material shadowing control. The lights file, usually with a .rad extension, must be placed in your game directory for Vrad to find it. It is a plain text file with one rule per line.

Lights file rules

Rule	Explanation
noshadow materials/name	Forces the named material to cast no shadows.
forcetextureshadow models/name.mdl	Forces shadows for the given model to take into account any alpha textures.
materials/name red green blue intensity	The named material will give off light of the given colour and intensity.
materials/name red green blue intensity hdr_red hdr_green hdr_blue hdr_intensity	The named material will give off light of the given colour and intensity, with separate LDR and HDR settings.
ldr:	prefix to make any rule only apply to LDR lighting.
hdr:	prefix to make any rule only apply to HDR lighting.

See also

• Map Compiling Theory
• HDR Lighting Basics
• VBSP
• VVIS