\ .\" This man page was generated by the Netpbm tool 'makeman' from HTML source. .\" Do not hand-hack it! If you have bug fixes or improvements, please find .\" the corresponding HTML page on the Netpbm website, generate a patch .\" against that, and send it to the Netpbm maintainer. .TH "Pamtris User Manual" 0 "15 April 2021" "netpbm documentation" .PP .SH NAME pamtris - triangle rasterizer featuring perspective-correct interpolation of generic vertex attributes and depth buffering .UN synopsis .SH SYNOPSIS \fBpamtris\fP \fB-width=\fP\fIwidth\fP \fB-height=\fP\fIheight\fP {\ \fB-num_attribs=\fP\fIattributes_per_vertex\fP [\ \fB-tupletype=\fP\fItupletype\fP\ ] | \fB-rgb\fP | \fB-grayscale\fP\ } [\ \fB-maxval=\fP\fImaxval\fP\ ] .PP All options can be abbreviated to their shortest unique prefix. You may use two hyphens instead of one to designate an option. You may use either white space or an equals sign between an option name and its value. .UN description .SH DESCRIPTION .PP This program is part of .BR "Netpbm" (1)\c \&. .PP \fBpamtris\fP can be used to draw a great variety of 2D and 3D graphics by composing arbitrarily complex pictures out of separate triangles, triangle strips and triangle fans. The program reads instructions written in a simple command script notation from Standard Input and outputs its results as a (potentially multi-image) PAM stream on Standard Output. .PP For example, the following input .nf \f(CW mode fan attribs 0 128 0 vertex 0 0 1 attribs 0 0 128 vertex 200 0 1 attribs 50 20 103 vertex 190 61 1 attribs 100 40 78 vertex 161 117 1 attribs 150 60 53 vertex 117 161 1 attribs 200 80 28 vertex 61 190 1 attribs 250 100 3 vertex 0 200 1 print \fP .fi .PP produces this: .PP .B Example pamtris output for FAN mode .IMG -C pamtris_fan.png .PP The input file gives triangle data by setting the appropriate drawing mode, if necessary, and then providing a list of vertices. Each vertex is also associated with a list of up to 20 "attributes," which are integer values between 0 and a given maxval. In the most common usage, you use \fBpamtris\fP to draw a visual image and a vertex has three attributes, which are an RGB specification of a color. Such attribute lists may be provided on a per-vertex basis. .PP Prior to effectively writing a PAM image to Standard Output, \fBpamtris\fP first rasterizes it onto an internal frame buffer, which consists of an "image buffer" and a "depth buffer." The image buffer consists of a sequence of \fIheight\fP rows containing a sequence of \fIwidth\fP tuples. There is one sample for each vertex attribute in every tuple plus an opacity (alpha) sample. Each tuple in the image buffer is also associated with an integer depth in the depth buffer, which determines whether subsequent drawing operations affect that particular tuple or not. This provides a way of depth-sorting graphical objects which is adequate for many purposes in 2D and 3D computer graphics. One prominent shortcoming of such an approach to depth-sorting, however, is that it does not automatically work with objects which are intended to appear "translucent," therefore requiring more elaborate strategies to incorporate said objects into pictures generated using this technique. .PP The opacity sample is the last sample of the tuple. \fBpamtris\fP manipulates opacity internally and for any tuple it is always either 0 or the maxval. The program does not provide the user direct control over the alpha image plane. .PP \fBpamtris\fP rasterizes triangles by approximating their visible area as a collection of tuples at particular positions in the frame buffer, and to each sample of every such tuple it assigns a value which is a perspective-correct interpolation between the values of the corresponding attribute for each vertex of the triangle. Whenever a tuple within the area of the frame buffer is produced, it is written to the corresponding position in the frame buffer if and only if it passes a depth test. This test works as follows: the depth value of every incoming tuple (which is itself an interpolation between the Z-coordinates of the vertices of the corresponding triangle) is compared against the value in the corresponding position in the depth buffer. If the depth value of the incoming tuple equals or is smaller than the depth value already present in said position in the depth buffer, the following happens. .IP \(bu Every sample \fIi\fP, where 0 ≤ \fIi\fP < \fInum_attribs\fP, of the tuple in the corresponding position in the image buffer is set to equal the value of the respective sample of the incoming tuple; and the alpha sample (the last one) is updated to the \fImaxval\fP; .IP \(bu The depth value in the corresponding position in the depth buffer is updated to a depth value directly proportional to that of the incoming tuple. .PP Otherwise, that particular tuple effects no change at all in the frame buffer. .PP The frame buffer is initially set so that all samples in every tuple of the image buffer contain the value 0, and all entries in the depth buffer contain the maximum permitted depth value. .PP The attributes' values, and therefore the samples in the output PAM images, have no fixed interpretation ascribed to them (except for the last image plane, which is deliberately supposed to represent tuple opacity information); one may ascribe any suitable meaning to them, such as that of colors, texture coordinates, surface normals, light interaction characteristics, texture influence coefficients for multi-texturing, etc. .UN examples .SH EXAMPLES .UN examples_fan .SS Fan Mode .PP The following command generates the image from the fan mode example at the top of the .UR #description DESCRIPTION .UE \& section. If the file \fBfan.tris\fP contains that code, you could process it with: .nf \f(CW $ pamtris -height=200 -width=200 -rgb fan.pam \fP .fi .UN examples_strip .SS Strip Mode .PP The following is an example of strip mode: .nf \f(CW mode strip attribs 255 0 0 # red vertex 0 200 1 vertex 50 0 1 attribs 0 0 0 # black vertex 100 200 1 attribs 0 205 205 # cyan vertex 150 0 1 attribs 0 0 255 # blue vertex 200 200 1 vertex 250 0 1 print \fP .fi .PP Save the above code in a file named \fBstrip.tris\fP (for instance) and process it with: .nf \f(CW $ pamtris -height=200 -width=200 -rgb strip.pam \fP .fi to yield: .PP .B Example pamtris output for STRIP mode .IMG -C pamtris_strip.png .UN examples_triangles .SS Triangle Mode .PP The following is an example of triangle mode: .nf \f(CW # yellow square mode strip attrib 155 155 0 vertex 50 50 100 vertex 50 200 100 vertex 200 50 100 vertex 200 200 100 # blue triangle mode triangles attrib 0 205 205 vertex 20 125 70 attrib 0 0 140 vertex 230 70 120 # Change "120" and see what happens vertex 230 180 120 # print \fP .fi .PP Save the above code in a file named \fBpierce.tris\fP (for instance) and process it with: .nf \f(CW $ pamtris -height=200 -width=200 -rgb pierce.pam \fP .fi to yield: .PP .B Example pamtris output for TRIANGLES mode .IMG -C pamtris_pierce.png .UN pamtris_c .SS Meta-programming .PP The \fBpamtris\fP command language is much too rudimentary to be used directly for any serious drawing; you will probably want to use a general purpose programming language to generate a temporary \fBpamtris\fP command file. .PP For example, the \fBdraw_polygon\fP procedure in the C program below outputs \fBpamtris\fP instructions to draw a regular polygon. It does this by generating a number of \fBvertex\fP instructions tracing around the perimeter of the corresponding circumscribed circle. (Note: The PAM image produced by piping the output of the below program into \fBpamtris\fP was subsequently downscaled through \fBpamscale\ -linear\ -xscale\ 0.25\ -yscale\ 0.25\fP to achieve an .UR #antialias anti-aliased .UE \& effect.) .PP .B Regular Polygons .IMG -C pamtris_polygons.png .nf \f(CW /* ----------------------- * * width = 512 * * height = 512 * * num_attribs = 3 * * tupletype = RGB_ALPHA * * ----------------------- */ #include #include #include #define PI 3.14159265358979323844 void draw_polygon (int const center_x, int const center_y, int const radius, int const sides) { printf("mode fan\en" "vertex %d %d 0\en", center_x, center_y); for(int i = 0; i <= sides; i++) { int const x = round(center_x + radius * cos(i*2.0*PI / sides)); int const y = round(center_y - radius * sin(i*2.0*PI / sides)); printf("vertex %d %d 0\en", x, y); } } int main(void) { puts("attribs 0 185 80"); /* color: green */ draw_polygon(300, 210, 150, 5); /* draws pentagon */ puts("attribs 255 15 240"); /* color: magenta */ draw_polygon(150, 320, 100, 7); /* draws heptagon */ puts("!"); } \fP .fi .UN options .SH OPTIONS .PP In addition to the options common to all programs based on libnetpbm (most notably \fB-quiet\fP, see .UR index.html#commonoptions Common Options .UE \&), \fBpamtris\fP recognizes the following command line options:
.TP \fB-width=\fP\fIwidth\fP Sets the width of the internal frame buffer and, by extension, of the output PAM images, given in number of columns. This must be an integer in the closed range [1, 8192]. .sp This option is mandatory. .TP \fB-height=\fP\fIheight\fP This is the height of the internal frame buffer and, by extension, of the output PAM images, given in number of rows. This must be an integer in the closed range [1, 8192]. .sp This option is mandatory. .TP \fB-num_attribs=\fP\fIattributes_per_vertex\fP This is the number of attributes per vertex. The depth of the output PAM images equals this value plus one (to accomodate the alpha plane). The argument must be an integer in the closed range [1, 20]. .sp The input instruction stream may override this with a \fBreset\fP command. .sp You must specify exactly one of \fB-num_attribs\fP, \fB-rgb\fP, and \fB-grayscale\fP. .TP \fB-tupletype=\fP\fItupletype\fP This is the tuple type for the output PAM images. The argument is a string which may be no longer than 255 characters. .sp The input instruction stream may override this with a \fBreset\fP command. .sp The default is a null string. .sp This option cannot be specified together with \fB-rgb\fP or \fB-grayscale\fP. .TP \fB-rgb\fP This is a convenience option which simply serves as an alias for \fB-num_attribs=\fP3 \fB-tupletype=\fPRGB_ALPHA. In other words, this option is a quick way to specify that you are going to use \fBpamtris\fP to draw RGB(_ALPHA) color images directly, and the three vertex attributes are the red, green and blue levels of the color associated with the vertex, in that order. .sp The input instruction stream may override this with a \fBreset\fP command. .sp You must specify exactly one of \fB-num_attribs\fP, \fB-rgb\fP, and \fB-grayscale\fP. .sp This option was new in Netpbm 10.85 (December 2018). .TP \fB-grayscale\fP Another convenience option, similar to \fB-rgb\fP; except this one is an alias for \fB-num_attribs=\fP1 \fB-tupletype=GRAYSCALE_ALPHA\fP. The one vertex attribute is the gray level associated with the vertex. .sp The input instruction stream may override this with a \fBreset\fP command. .sp You must specify exactly one of \fB-num_attribs\fP, \fB-rgb\fP, and \fB-grayscale\fP. .sp This option was new in Netpbm 10.85 (December 2018). .TP \fB-maxval=\fP\fImaxval\fP Sets the maxval of the output PAM images, which is also the maximum permitted value for each vertex attribute. This must be an integer in the closed range [1, 65535]. .sp The default value is 255. .sp The input instruction stream may override this with a \fBreset\fP command. .UN instruction_code .SH INSTRUCTION CODE .PP The input for \fBpamtris\fP consists of a stream of text lines read from Standard Input. .PP Empty lines or lines that contain only white space characters are called blank lines and are ignored. .PP When a \fB#\fP occurs anywhere in a line, \fBpamtris\fP ignores it along with every character after it. In other words, everything from the \fB#\fP until the end of the line receives the same treatment as white space. .PP Lines which are not blank must contain a sequence of strings, called tokens, separated by white space. The first such token must be one of the commands recognized by \fBpamtris\fP, and all further tokens are interpreted as the arguments for that command, if it takes any. When an insufficient number of arguments is provided for a command, the line is considered invalid and is given the same treatment as a blank line. The same happens when an out of range argument or one of a kind different of what is expected is given (for example, when you give a string of letters where a numerical value is expected), or when an unrecognized command/argument is found. When a number of arguments greater than that required for a particular command is provided, only the portion of the line up to the last required argument is considered and any further tokens are ignored. .PP \fBpamtris\fP is case-insensitive. That is, \fBmode\fP, \fBMODE\fP, \fBmODe\fP, etc. are all treated the same way. .PP The commands recognized by \fBpamtris\fP are: .TP \fBmode\fP .TP \fBattribs\fP .TP \fBvertex\fP .TP \fBprint\fP .TP \fBclear\fP .TP \fBreset\fP .TP \fBquit\fP .PP You may use a minimum unique abbreviation of a command name. You may use an exclamation mark (\fB!\fP) in place of the \fBprint\fP command name and an asterisk (\fB*\fP) in place of \fBclear\fP. .PP The functions of the commands are as follows. .TP \fBmode\fP { triangles | strip | fan } .sp This makes \fBpamtris\fP enter a new drawing mode. The argument is a word which specifies the mode to change to. Instead of a full argument name, it is permissible to provide a minimum unique abbreviation, which has the same effect. The drawing mode will remain the same until the next \fBmode\fP command is given. .sp This command also resets the current vertex list, which is (re)initialized to an empty state after the command is executed. One may add new vertices to this list through successive invocations of the \fBvertex\fP command (see below). You do not have to worry about providing "too many" vertices, since the vertex list is virtualized: \fBpamtris\fP maintains only the state pertaining to three vertices at any one time. The current vertex list is initially empty. .sp It is permissible to give \fBpamtris\fP a \fBmode\fP command which instructs it to enter a drawing mode it is currently already in. One might use this approach to reset the current vertex list without changing the current drawing mode. .sp Regardless of the current drawing mode, the program immediately rasterizes a new triangle into the frame buffer as soon as you provide the necessary vertices for it through the current vertex list. (If you reset the vertex list before giving all the vertices necessary to draw a new triangle, the program effectively discards from the list any vertices that might have been pushed into the vertex list up to that point without using them to draw any new triangles.) .sp In the following descriptions of each drawing mode, triangles' and vertices' indices (ordinal numbers) are 0-based. .sp The \fBtriangles\fP argument instructs \fBpamtris\fP to enter the "TRIANGLES" drawing mode. While in this mode, a series of separate triangles is constructed. Every three vertices pushed into the current vertex list specify a new triangle. Formally, this means that every \fIN\uth\d\fP triangle is specified by vertices 3*\fIN\fP, 3*\fIN\fP\ +\ 1, and 3*\fIN\fP\ +\ 2. This is the default initial mode and is therefore not required to be set explicitly before drawing any triangles. .sp The \fBstrip\fP argument instructs \fBpamtris\fP to enter the "STRIP" drawing mode. While in this mode, \fBpamtris\fP constructs a "triangle strip." That is, the first three vertices pushed into the current vertex list specify the first triangle, and every new vertex pushed after that specifies, together with the previous two, the next triangle. Formally, this means that every \fIN\fP\uth\d triangle is specified by vertices \fIN\fP, \fIN\fP\ +\ 1, and \fIN\fP\ +\ 2. .sp The \fBfan\fP argument instructs \fBpamtris\fP to enter the "FAN" drawing mode. While in this mode, a so-called "triangle fan" is constructed. That is, the first three vertices pushed into the current vertex list specify the first triangle, and every new vertex pushed after that specifies, together with the previous vertex and the first one, the next triangle. Formally, this means that every \fIN\fP\uth\d triangle is specified by vertices \fI0\fP, \fIN\fP\ +\ 1, and \fIN\fP\ +\ 2. .TP \fBattribs\fP \fIa0\fP \fIa1\fP \fIa2\fP ... \fIanum_attribs - 1\fP .sp This updates the current attribute values list. This command takes as arguments a sequence of \fInum_attribs\fP integers which represent the values of the attributes to be associated with the next vertex. This sequence of values is the just mentioned "current attribute values list." .sp Each \fIi\uth\d\fP argument, where 0 ≤ \fIi\fP < \fInum_attribs\fP, indicates the value to be assigned to the \fIi\fP\uth\d attribute of the current attribute values list. All arguments must be integer values in the closed range [0, \fImaxval\fP]. If a number of arguments less than the current value of \fInum_attribs\fP is given, the command is considered invalid and is therefore ignored. .sp The current attribute values list remains unchanged until the next valid \fBattribs\fP or \fBreset\fP command is given. The \fBattribs\fP command allows one to change the values of each attribute individually, while the \fBreset\fP command is not specifically designed for that function, but it has the side effect of setting all values in the current attribute values list to the \fImaxval\fP (see below). .sp All values in the current attribute values list are initially set to the \fImaxval\fP.
\fBvertex\fP \fIx\fP \fIy\fP \fIz\fP [\fIw\fP] .sp Adds a new vertex to the current vertex list (see the \fBmode\fP command above), assigning the values of the arguments to its respective coordinates, and the values in the current attribute values list (see the \fBattribs\fP command above) to the respective entries in the attribute list associated with the vertex. .sp \fIx\fP, \fIy\fP and \fIz\fP must be integer values in the closed range [-32767, 32767]. \fIx\fP and \fIy\fP represent, respectively, the column and row of the tuple which corresponds to the location of the vertex. Such values may correspond to tuples outside the limits of the frame buffer. The origin of the coordinate system is at the top-left tuple of the frame buffer. The X-axis goes from left to right, and the Y-axis from top to bottom. A negative value for \fIx\fP indicates a column that many tuples to the left of the leftmost column of the frame buffer. Likewise, a negative value for \fIy\fP indicates a row that many tuples above the uppermost row of the frame buffer. Observe that those coordinates correspond directly to a particular point in the coordinate system delineated above, regardless of whether you are trying to draw an image which is supposed to look as if viewed "in perspective" or not; \fBpamtris\fP does \fInot\fP "warp" the coordinates you give in any way. Therefore, if you want to draw images in perspective, you must compute values for \fIx\fP and \fIy\fP already projected into \fBpamtris\fP' coordinate system yourself, using an external perspective projection method, prior to giving them to the program. .sp The \fIz\fP parameter represents the Z-coordinate of the vertex, which is used to compute depth values for tuples within the areas of rasterized triangles. Intuitively, smaller values for \fIz\fP mean "closer to the viewer," and larger ones mean "farther away from the viewer" (but remember: as said above, the \fIx\fP and \fIy\fP coordinates are not warped in any way, which implies that they are not affected by \fIz\fP; neither by the next parameter, for that matter). .sp Optionally, you may provide a \fIw\fP parameter which represents a "perspective correction factor" used to properly interpolate vertex attributes across the area of the corresponding triangle. This must be an integer value in the closed range [1, 1048575]. If you don't provide a value for it, the default value of 1 is used (hence, if you want to nullify the effects of perspective correction on a triangle so the output samples are computed as if just linearly interpolated, simply do not provide a value for \fIw\fP for any vertex of the triangle). If, however, you intend to draw 3D geometry in perspective, you must provide an appropriate value for this parameter, otherwise the output images might look very wrong. \fIw\fP was new in Netpbm 10.85 (December 2018). .sp Consider the .UR https://en.wikipedia.org/wiki/Viewing_frustum typical model .UE \& of the so-called "viewing frustum" used to project vertices in 3D "world space" onto a planar "image space." If we adopt the convention that a "z-plane" means any plane parallel to the view-plane (a.k.a. picture plane, a.k.a. near plane), the value of \fIw\fP for a vertex should then be the (smallest/euclidean/orthogonal) distance in pixels between the projection reference point (PRP, or "eye") and the z-plane containing the vertex. One way to compute this value amounts to simply taking the dot product between the 3D vector \fBr\fP and the 3D unit vector \fBn\fP, where \fBr\fP is the vector which goes from the projection reference point (PRP, or "eye") to the vertex, and \fBn\fP is a view-plane normal (VPN) of unit length which points away from the PRP. In other words, this is equal to the length of the orthogonal projection of \fBr\fP on the line "determined" by \fBn\fP. .sp (Note: For any two 3D vectors \fBa\fP and \fBb\fP, with respective real scalar components ax, ay, az and bx, by, bz, the dot product between \fBa\fP and \fBb\fP is simply ax*bx\ +\ ay*by\ +\ az*bz.) .TP \fBprint\fP .sp This writes a PAM image to Standard Output whose raster is a copy of the current contents of the image buffer. The values of the WIDTH and HEIGHT fields are the same as the width and height, respectively, of the frame buffer, which were given on the command line during program invocation. The MAXVAL field is equal to the current maxval; the DEPTH field is equal to the current value of \fInum_attribs\fP + 1; and the TUPLTYPE field is equal to the current tupletype. .sp This command has no effect upon the current drawing state. E. g. it does not modify the current drawing mode, the current vertex list, etc. .sp One may issue an arbitrary number of \fBprint\fP commands at different positions in the input instruction sequence to produce a multi-image PAM stream. .TP \fBclear\fP [ image | depth ] .sp Clears the frame buffer. That is, all samples in the image buffer are once again set to 0, and all entries in the depth buffer are once again set to the maximum permitted depth value. .sp Optionally, one may provide an argument to only clear either the image buffer or the depth buffer individually, while leaving the other intact. With the \fBimage\fP argument, only the image buffer is cleared; with the \fBdepth\fP argument, only the depth buffer is cleared. Instead of full argument names, one may provide a minimum unique abbreviation, which has the same effect. The single character \fBz\fP is also accepted as an alias for \fBdepth\fP. .sp Like the \fBprint\fP command, this command has no effect upon the current drawing state either. .TP \fBreset\fP \fImaxval\fP \fInum_attribs\fP [\fItupletype\fP] .sp This updates the current maxval and number of attributes per vertex (num_attribs), resetting the image buffer with a new maxval and number of samples per tuple while at it. The parameter \fImaxval\fP must be an integer in the closed range [1, 65535], and \fInum_attribs\fP must be an integer in the closed range [1, 20]. .sp Optionally, after the second argument, one may provide a string to be assigned to the current \fItupletype\fP. The string goes from the first character after the second argument which is not white space and continues until (and including) the last character before the end of the line which is not white space. If a new tupletype is not provided, or the provided string is longer than 255 characters, the empty string is assigned to the current \fItupletype\fP. .sp The side effects of running this command are .IP \(bu The new image buffer is completely cleared once the command is executed. .IP \(bu All values in the current attribute values list are set to the new maxval. .IP \(bu The current vertex list is reset. .sp However, it does not touch the depth buffer: it is left the same way as it was found before the command. Also the drawing mode remains the same (e. g. if \fBpamtris\fP was in FAN mode, it will continue in that same mode, etc.). .sp If this command is given with an invalid value for \fImaxval\fP or \fInum_attribs\fP, it is ignored and therefore none of the above side effects apply, nor do the current maxval, num_attribs or tupletype change at all. .sp It is permissible to give a value for \fImaxval\fP and \fInum_attribs\fP equal to the current maxval and num_attribs, respectively, although the above side effects will still apply even in such cases. .sp Since this command deals with memory allocation, it may fail to execute successfully. If that happens, no lines of input will be read anymore and \fBpamtris\fP will be terminated as if the \fBquit\fP command was given. .TP \fBquit\fP .sp This terminates \fBpamtris\fP. It will not read any more lines of input after this command. .UN tips .SH TIPS .SS Texturing .PP It is possible to apply so-called "textures" to images produced with \fBpamtris\fP by using a pair of vertex attributes as texture coordinates, then using .BR "\fBpamchannel\fP" (1)\c \& to select the appropriate channels in the output image(s), and finally processing the result through .BR "\fBpamlookup\fP" (1)\c \&, providing the desired texture file as a "lookup table." If you are drawing pictures in perspective, make sure to provide adequate values for the \fIw\fP parameter to your vertex commands ( .UR #cmd_vertex see above .UE \&) so that the resulting samples in the images produced by \fBpamtris\fP are perspective-correct. You might want to consider using .BR "\fBpnmtile\fP" (1)\c \& to make textures which are inteded to be "repeated" along triangle meshes. .PP The animated GIF below is an example of what can be achieved using the technique described above (Earth texture from .UR https://visibleearth.nasa.gov/view.php?id=73580 nasa.gov .UE \&). .PP .B Rotating Earth .IMG -C pamtris_earth.gif .UN antialias .SS Anti-aliased edges .PP \fBpamtris\fP performs no anti-aliasing on triangle edges by itself. However, it is possible to obtain anti-aliased images through a "super-sampling" approach: draw your image(s) at a size larger than the desired final size, and then, when all postprocessing is done, downscale the final image(s) to the desired size. Drawing images with twice the desired width and height, then downscaling them to the intended size while disregarding gamma (i.e. what \fBpamscale\ -linear\fP does) often produces good enough results; but the larger the ratio \fI "size\ of\ original\ image"\ /\ "size\ of\ downscaled\ image" \fP, the better the quality of the anti-aliasing effect. .UN seealso .SH SEE ALSO .BR "pampick" (1)\c \& .BR "pamchannel" (1)\c \& .BR "pamstack" (1)\c \& .BR "pamlookup" (1)\c \& .BR "pamarith" (1)\c \& .BR "pamscale" (1)\c \& .BR "pamdepth" (1)\c \& .BR "pamexec" (1)\c \& .BR "pam" (1)\c \& .UN history .SH HISTORY .PP \fBpamtris\fP was new in Netpbm 10.84 (September 2018). .SH DOCUMENT SOURCE This manual page was generated by the Netpbm tool 'makeman' from HTML source. The master documentation is at .IP .B http://netpbm.sourceforge.net/doc/pamtris.html .PP