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



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

SSYYNNOOPPSSIISS
       SSGG33dd
       SSGG33dd hheellpp
       SSGG33dd   [--ww]   [--zz]   eelleevv==_n_a_m_e	ccoolloorr==name[_,_n_a_m_e_,_n_a_m_e]	 [vveeccttoorr==_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 computers.  At  startup,  one  graphics
       window and several  interface  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  parameter 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
       information   needed   for  lighting  calculations.  Thus, large dimen-
       sions such as 1000 rows x 1000 columns may cause memory 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  ADJUST-
       MENT:   Hold   down  the Ctrl key while manipulating 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  Engineering
       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)
