Adds the names to the list of attributes that will be reported when the "attributes" partition information value is specified. See also the attr command below.

Causes nirt to read the eye point and either the orientation quaternion (new format) or the view-rotation matrix (old format) from the standard input, and fire a single ray from the point in the specified direction. This option allows nirt to be called directly from within mged using the nirt and rrt commands.

Causes nirt to perform a backout command before the first shoot command (see the description of these two commands below). This is probably only useful with the -M option.

Causes nirt to adjust the setting of rt_bot_minpieces to the indicated value. A value of zero here indicates that the "pieces" methodology should not be used. A value greater than zero indicates that all BOT primitives containing more than rt_bot_minpieces triangles should be broken down into a separate piece for each triangle. This can result in significant improvement in raytrace speed at the cost of more memory use.

Causes nirt to run the script string before reading the standard input. Multiple commands in script may be separated with a semicolon ';'. Scripts specified with either the -e or -f options are executed in the order in which they are specified on the command line.

Causes nirt to load the predefined format (see -L) format or script file before reading standard input. Scripts specified with either the -e or -f options are executed in the order in which they are specified on the command line.

Causes nirt to ignore any -e or -f options specified previously on the command line.

List output formatting options.

Causes nirt to run in silent (that is, non-verbose) mode. In this mode, which is useful in a pipeline, nirt does not print its initial lines of output or the prompt.

Causes nirt to run in verbose mode. The default is verbose mode, except if standard input has been redirected, in which case the default is silent mode.

Set flag (n) for enable/disable informational header (n=1 [on] by default, always off in silent mode).

Sets the useair member of the rt_i structure to n. See the discussion of the useair command below.

Causes nirt to handle multiple regions' claims to segments of a ray according to action n. The argument n may be any of the values 0, 1, 2, or 3, or their corresponding key words "resolve", "rebuild_fastgen", "rebuild_all", or "retain". See the discussion of the overlap_claims command below.

Sets the librt(3) debug flags to the hexadecimal bit vector v. See the discussion of the libdebug command below.

Sets nirt's own debug flags to the hexadecimal bit vector v. See the discussion of the debug command below.

Sets the ray origination point to (x, y, z). If this command is invoked with no arguments, nirt prints the current ray origination point in model coordinates. Default is (0, 0, 0). Changing (x, y, z) will change (h, v, d), according to the current direction vector.

Sets the ray origination point to (h, v, d). If this command is invoked with only two arguments, nirt interprets them as h and v, and d retains its previous value. If invoked with no argument, the command causes nirt to print the current ray origination point in view coordinates. Default is (0, 0, 0). Changing (h, v, d) will change (x, y, z), according to the current direction vector.

Sets the direction vector to the unit vector in direction (dx, dy, dz). If this command is invoked with no arguments, nirt prints the current direction vector. Default is (-1, 0, 0). Changing (dx, dy, dz) will change the azimuth and elevation angles.

Sets the direction vector to point from azimuth = az and elevation = el. If this command is invoked with no arguments, nirt prints the current values of the azimuth and elevation angles. Default is (0, 0). Changing azimuth and elevation will change the direction vector.

Fires a ray from the current origination point in the current direction.

Sets "rt_bot_minpieces" to the new value n. If n is not provided, the current value of "rt_bot_minpieces" is displayed. See the discussion of the -B option above for more details.

Command to set the backout flag. With no option, prints the current value. When activated, backs the ray origination point out of the geometry: h and v retain their previous values and d is set to Dmax, the largest value of d anywhere in the geometry. Default is 0 (deactivated), 1 is active.

Sets the useair member of the rt_i structure to the integer n. If n is 0, then nirt ignores any air in the geometry. If this command is invoked with no arguments, nirt prints the current value of useair. Default is 0.

Specifies how to handle multiple regions' claims to segments of a ray. If n is 0 or "resolve", then all overlaps are resolved in favor of a single region and any other claimants are ignored. If n is 2 or "rebuild_all", then all overlaps are rebuilt, so any overlapping regions along the ray create individual (geometrically intersecting) partitions. If n is 3 or "retain", then all overlaps are retained. In this case, the resulting partitions are always geometrically disjoint, each one is owned by a single region according to the current overlap resolution strategy, but every claimant is recorded. If n is 1 or "rebuild_fastgen", then nirt takes on FASTGEN behavior, so overlaps of plate-mode primitives are rebuilt, but other overlaps are retained. This command is useful with the claimant_count, claimant_list, and claimant_listn output items. Default is "resolve".

When used with one or more names, adds the names to the list of attributes that will be printed when the "attributes" value is requested in the output format string.

The -p option to the attr command causes it to print the list of attributes that will be reported.

The -f option clears the attributes table.

Causes nirt to read and write all distances and locations in units of u. Valid choices for u are "mm"; "cm"; "m"; "in"; and "ft". If this command is invoked with no arguments, nirt prints the current choice of I/O units. Default is the units of model.g.

Sets the action for output statements of type t. If this command is invoked with only one argument, a valid statement type, nirt prints the current format and items for the specified type. See the discussion of output statements below.

Sets the destination for subsequent output actions to d. If the first character of d is `|', then d is interpreted as a pipeline to which to write its output. Otherwise, if d is the string "default", nirt sets the destination to the standard output. Otherwise, d is interpreted as a file. In any event, d is not closed until the user quits nirt or resets the destination by another invocation of the dest command. If this command is invoked with no arguments, nirt prints the current value of d. Default is "default", that is, the standard output.

Sets the name of the state file to which to dump and from which to load state information. See the discussion of the dump and load commands below. If this command is invoked with no arguments, nirt prints the current name of the state file. Default is "nirt_state".

Writes state information to the state file. The ray origination point and direction vector, useair, units, destination, and all the output actions are dumped.

Reads state information from the state file. The state file loaded may contain any nirt commands.

Prints the current value of the output item item. See the discussion of output statements below.

Sets the librt(3) debug flags (the debug member of the rt_g structure) to the hexadecimal bit vector v. These flags control the amount and kind of diagnostic print statements librt(3) executes. If v is 0, then no diagnostics are produced. If this command is invoked with no arguments, nirt prints the current value of v and the names of any of its bits that are set. Default is 0.

Sets nirt's internal debug flags to the hexadecimal bit vector v. These flags control the amount and kind of diagnostic print statements nirt executes. If v is 0, then no diagnostics are produced. If this command is invoked with no arguments, nirt prints the current value of v and the names of any of its bits that are set. Default is 0.

Prints a help menu to the standard output.

Quits nirt.

Ray. The first output statement executed whenever the s command is invoked.

Head. Executed immediately after the ray statement if the ray hits anything.

Partition. Executed once for each partition along the ray if the ray hits anything.

Foot. The last output statement executed if the ray hits anything.

Miss. Executed immediately after the ray statement if the ray hits nothing.

Overlap. Executed once for each overlap along the ray if the ray hits anything.

Gap. Executed once for each gap along the ray if the ray encounters any gaps.

x coordinate of ray origination point.

y coordinate of ray origination point.

z coordinate of ray origination point.

d coordinate of ray origination point.

h coordinate for the entire ray.

v coordinate for the entire ray.

x component of direction vector.

y component of direction vector.

z component of direction vector.

azimuth of view (i.e., of ray direction).

elevation of view (i.e., of ray direction).

A string variable consisting of the names and values of the attributes requested by the attr command or the -A command line option.

x coordinate of entry into current region.

y coordinate of entry into current region.

z coordinate of entry into current region.

d coordinate of entry into current region.

x coordinate of exit from current region.

y coordinate of exit from current region.

z coordinate of exit from current region.

d coordinate of exit from current region.

line-of-sight distance through current region.

scaled line of sight: product of line-of-sight distance through current region and region solidity (sometimes called "percent LOS").

full path name of current region.

name of current region, as might be obtained by passing path_name to basename(1).

region ID of current region.

number of regions claiming this partition (that is, participating in a retained overlap).

space-separated list of names of regions claiming this partition (that is, participating in a retained overlap).

Same as claimant_list, except that it is newline-, rather than space-separated.

entry obliquity for current region.

exit obliquity for current region.

x component of entry normal vector

y component of entry normal vector

z component of entry normal vector

h component of entry normal vector

v component of entry normal vector

d component of entry normal vector

x component of exit normal vector

y component of exit normal vector

z component of exit normal vector

h component of exit normal vector

v component of exit normal vector

d component of exit normal vector

entry-surface ID of entry solid.

exit-surface ID of exit solid.

x coordinate of entry into gap.

y coordinate of entry into gap.

z coordinate of entry into gap.

line-of-sight distance through gap.

name of one of the overlapping regions.

name of the other overlapping region.

region ID of one of the overlapping regions.

region ID of the other overlapping region.

name of one of the overlapping solids.

name of the other overlapping solid.

line-of-sight distance through the overlap.

x coordinate of entry into overlap.

y coordinate of entry into overlap.

z coordinate of entry into overlap.

d coordinate of entry into overlap.

x coordinate of exit from overlap.

y coordinate of exit from overlap.

z coordinate of exit from overlap.

d coordinate of exit from overlap.