


SG3d()            MISC. REFERENCE MANUAL PAGES             SG3d()



NAME
     _S_G_3_d        3 Dimensional Surface Renderer

SYNOPSIS
     SG3d
     SG3d help
     SG3d    [-w]    [-z]    elev=_n_a_m_e     color=_n_a_m_e[,_n_a_m_e,_n_a_m_e]
     [vector=_n_a_m_e] [sites=_n_a_m_e]
     [3dview=_n_a_m_e] [script=_n_a_m_e]

DESCRIPTION
     _S_G_3_d is a tool for viewing a data surface  in  three  dimen-
     sions  using  GRASS  on _S_i_l_i_c_o_n _G_r_a_p_h_i_c_s _I_R_I_S 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 _M_e_n_u_s panel.  To
     hide  the pop up windows, click again on their toggle button
     in the _M_e_n_u_s panel - using the _Q_u_i_t or  _C_l_o_s_e  options  from
     the  window  manager's  menu  bar  will cause the program to
     exit.

COMMAND LINE OPTIONS
     Flags

     -_w   Enable writing to script files

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

     Parameters

     _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




Sun Release 4.1           Last change:                          1






SG3d()            MISC. REFERENCE MANUAL PAGES             SG3d()



     If the user simply types _S_G_3_d without  specifying  parameter
     values on the command line, the program will prompt the user
     to enter these.

NOTES
     Environment variables _S_G_3_D__W_I_D_T_H and _S_G_3_D__H_E_I_G_H_T  may be set
     to  define  the width and height (in pixels) of the graphics
     window at startup.  All _S_G_3_d 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 _b_e_s_t resolution available in  _S_G_3_d.   For
     speed,  the  entire raster file is loaded into memory, along
     with vertex color and other surface information  needed  for
     lighting  calculations.  Thus, large dimensions such as 1000
     rows x 1000 columns may cause memory problems.  _S_G_3_d 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 _S_G_3_d 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 manipulating the
     dial or slider for fine control.

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

BUGS
     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 _t_r_i_a_n_g_u_l_a_t_e option should make  the  holes  disap-
     pear.

AUTHORS
     Dave Gerdes and Bill Brown, U.S. Army Construction Engineer-
     ing Research Laboratory








Sun Release 4.1           Last change:                          2



