AB Shadow Map will greatly accelerate rendering with Raymarcher (2-10 times).. Map will be created when the first sample is required and the progress window might show up if it takes more than a few moments.
Size - Same as size of ordinary Shadow Map, sets the size (in pixels squared) of the shadow map that's computed for the light.
Quality - The default 0.9 should be good for most purposes. You might reduce this if map size is very large and you must conserve memory.
Samples/Ray - Maximum number of samples in depth (per map pixel). On average, map holds only a few samples in depth, so this limit may only be needed if accuracy is set to near 1 and number of depth samples increases.
Bias - Similar to bias of ordinary Shadow Maps, Bias moves the shadow away from the shadow-casting volume.
Use this options if the shadow map appears aliased. You might need to use this option for HyperSolids. This could greatly increase map creation time, so be careful with Quality and Samples settings.
Disabled - For each map pixel, only one ray is cast.
5 Star - In areas of contrast, five rays are cast and blended in one map pixel.
Halton - For best quality. In areas of contrast, custom number of rays is cast and blended in one map pixel.
Quality - The higher the quality, the more pixels will have to be super-sampled.
Samples - Number of samples is only valid if Halton is selected.
This group of controls enables further rendering optimizations. If you have static clouds and a camera flying through them, you'd want shadow map to be precomputed only once and reused during animation. This set of parameters enables this as well as some other variations.
Static - During a rendering, when a Shadow Map is created, it is used unchanged during the entire rendering. Use only if all involved elements are static (light, particles, AfterBurn). It doesn't matter if the geometry is changing, you can still use Static setting. This option is a great time-saver for a fly-through a static cloud layer.
Every Frame - Default setting. Map is generated for every frame of the rendering.
Range - Use this setting if light, particles or AfterBurn are animated only within a time range.
Use - AB Shadow Map does only volumetric component of the shadows, which must be combined with independently generated shadows cast from geometry. You must check this if you want the light to cast shadows from geometry. Select shadow generator type (any 3ds Max shadow generator) from a drop-down and a new rollout will open with its parameters. Ray-trace is the default setting.
Note: When using AB Shadow Map, you MUST disable "Atmosphere Shadows" option in light's rollout. Never mix those two types of shadows as you won't see any speed improvement.