SG3d(1) 	       Grass User's Manual		  SG3d(1)



NNAAMMEE
       SSGG33dd  -	3 Dimensional Surface Renderer for use on Silicon
       Graphics sorkstations

SSYYNNOOPPSSIISS
       SSGG33dd
       SSGG33dd hheellpp
       SSGG33dd  [--ww]  [--zz]  eelleevv==_n_a_m_e  ccoolloorr==name[_,_n_a_m_e_,_n_a_m_e]  [vveecc--
       ttoorr==_n_a_m_e] [ssiitteess==_n_a_m_e] [33ddvviieeww==_n_a_m_e] [ssccrriipptt==_n_a_m_e]

DDEESSCCRRIIPPTTIIOONN
       SG3d  is  a  tool  for  viewing	a data surface	in  three
       dimensions using  GRASS	on Silicon Graphics IRIS  comput-
       ers.   At startup, one graphics window and several  inter-
       face  windows are  visible.    Other   interface   windows
       pop  up when their appropriate toggle button is clicked in
       the Menus panel.  To hide  the pop up windows, click again
       on their toggle button in the Menus panel - using the Quit
       or  Close  options  from the  window  manager's	menu  bar
       will cause the program to exit.

CCOOMMMMAANNDD LLIINNEE OOPPTTIIOONNSS
       FFllaaggss



	    _-_w	 Enable writing to script files

	    _-_z	  Use  site  category  as  Z value (height)  when
       displaying
		 sites



       PPaarraammeetteerrss



	    _e_l_e_v
		 Raster file for Elevation

	    _c_o_l_o_r
		 Raster file(s) for Color  (1  or  3  files).  If
       three files
		 are   given,	the  first  will  be used for the
       red com-
		 ponent, the second for   the	green	component
       and  the
		 third	for  the blue component. When using three
       files,
		 each file must contain values in the range  0	-
       255.

	    _v_e_c_t_o_r
		 Vector overlay file

	    _s_i_t_e_s
		 Sites overlay file

	    _3_d_v_i_e_w
		 3d viewing parameters file

	    _s_c_r_i_p_t
		 Automatically run script file




       If the user simply types SG3d without  specifying  parame-
       ter values on the command line, the  program  will  prompt
       the user to enter these.

NNOOTTEESS
       Environment  variables  SG3D_WIDTH and SG3D_HEIGHT  may be
       set to  define  the width and height (in  pixels)  of  the
       graphics  window  at  startup.	All  SG3d windows may  be
       resized	using the  window  manager's normal  controls  at
       any  time.   Text  in  the control panels is not scalable,
       however,  so  the  text will disappear  if  the	panel  is
       sized too small.


       Before  starting  the  program,	check  the resolution and
       dimen- sions  of the current GRASS region.   The   current
       resolution will determine the best resolution available in
       SG3d.   For speed,  the	entire raster file is loaded into
       memory, along with vertex color and other surface informa-
       tion  needed  for  lighting   calculations.   Thus,  large
       dimensions such as 1000 rows x 1000 columns may cause mem-
       ory problems.  SG3d uses 12 bytes  of  memory   for   each
       vertex,	therefore  a  1000  x 1000 image would require 12
       megabytes for data alone.


       The GRASS text window is used by SG3d  to  issue   prompts
       and  warnings   and  to input filenames.  Therefore, after
       starting the program, place the GRASS text  window   where
       it  can	be seen and typed into.


       Any  sliders  and  dials used in the control panels have a
       FINE ADJUSTMENT:  Hold  down  the Ctrl key  while  manipu-
       lating the dial or slider for fine control.


       Full  documentation  detailing  the action associated with
       each control is available in the tutorial.

BBUUGGSS
       Sometimes very small holes will appear  in  the	 surface.
       If  they  appear as points when drawing polygons with grid
       over- laid, the bug is in the  Graphics	Library  and   it
       should  be fixed in future versions of IRIX.  If the holes
       appear along an edge of a polygon, it is apparently due to
       the   way   non-  planar  polygons  are	interpreted.   In
       this case, drawing using  the  triangulate  option  should
       make  the  holes  disap- pear.



AAUUTTHHOORRSS
       David  Gerdes and Bill Brown, U.S. Army Construction Engi-
       neering Research Laboratory

       _L_a_s_t _c_h_a_n_g_e_d_: _$_D_a_t_e_: _2_0_0_2_/_0_1_/_2_5 _0_5_:_4_5_:_3_2 _$



GRASS 5.0						  SG3d(1)
