The DIVE FAQ Page

This is the DIVE frequently asked questions page. It is currently rather limited but we intend to add to it as questions arise. If you have a question like the ones below, or something you think would be useful in this FAQ, send an email to  dive-help@sics.se.

See also the online DIVE manual.

Installation:

1. Why am I getting erros of type 'file doesn't exist', or why don't I have complete scenes, on NT DIVE?

1. How can I optimize DIVE performance for my conditions?

1. DIVE seems to be rejecting my Tcl/Tk code to make Tk UI objects, why?
2. How can I switch textures in a view with a keypress?
3. How can sounds be made to play without the delay caused by sample download time?

1. Why can't I see some textures when using Linux-Mesa-3DfxVoodoo1(Coming DIVE release)?
2. Why do I have to be root when using Linux-Mesa-3DfxVoodoo1(Coming DIVE release)?

1. Why can't I use the stereo option on the render menu?

1. Why isn't there a win95/98 version of DIVE?

Installation:

1. Why am I getting errors of  type 'file doesn't exist', or why don't I have complete scenes, on NT DIVE?
       The current NT realease needs to be installed on the C drive. The reason for this is that Dive uses a preprocessor to process the datafiles before parsing (so that you may use preprosessor macros in the data files), but the current preprocessor is taken from the Cygnus "win32unix" distribution and doesn't know anything about Windows drive letters. If your datafiles contain an include-directive (which tutorial does), the preprocessor assumes that the include files are located on the C drive (which in your case they are not), therefore the problem. Move your datafiles to the C drive and set your DIVEPATH variable accordingly.

Running DIVE :

1. How can I optimize DIVE performance for my conditions?
       Copy the '.dive_configure' file from your data directory to your HOME directory and change variables that affect your performance (e.g. render_* variables) and delete the others. The variable values in your new file override the default values. Try for instance lowering 'render_interval'.
 

1. DIVE seems to be rejecting my Tcl/Tk code to make Tk UI objects, why?
    The trick when using Tk commands in DIVE Tcl scripts is to make sure that they are executed by a diva actor entity (since these entities are the only ones who understand Tk). This means that if you want to create a Tk window from a DIVE Tcl script in an arbitrary entity, you have to use dive_send to "send" the Tk cmds to the appropriate actor entity. Which actor to use depends of course on where you want the window to appear, i.e., on what physical screen. Typically you find the actor you are "looking for" via listening to events, for instance the interaction event has an actor as one of its parameters.
Have a look at body_cartoon.vr and walkman.tcl, both files contain Tcl scripts that create Tk UI objects.

2. How can I switch textures in a view with a keypress?
   object {
     material "white"
     nobackface on
     texture "texture1.gif"
     texture "texture2.gif"
     view {
       name "xyz"
       texture_index 0
       N_M_POLY 1 4 (T_PER_VERTEX)
       N_POLY 4
       t 0 0
       v 19.2 3.0 -19.2
       t 1 0
       v -19.2 3.0 -19.2
       t 1 1
       v -19.2 3.0 19.2
       t 0 1
       v 19.2 3.0 19.2
     }
     begin.tcl
       proc on_new {type id origin} {
         global textind
         set textind 0
       }
       proc change_texture {event type device key origin} {
         global textind
         if {$key != "Control_L"} {
           # Left Ctrl triggers the texture switch
           return
         }
         set vid [dive_find_entity_byname "xyz"]
         if {$textind == 0} {
           set textind 1
         } else {
           set textind 0
         }
         dive_texture_index $vid $textind
       }
       dive_register INPUT_SIGNAL KEYBOARD_KEY_DOWN [dive_self] "" change_texture
       dive_register ENTITY_NEW_EVENT NULL [dive_self] "" on_new
     end.tcl
   }

3. How can sounds be made to play without the delay caused by sample download time?
 
    Store the sound in a buffer when creating the object you want the sound to play in, then use the (global) variables describing the sound with  dive_readbuf_withMIME to play the sound without delay.

   begin.tcl
     global sound1 len1 type1
     set sound1 [dive_readURL_as_addr \
       "http://www.sics.se/dive/data/songs/porsche.au" len1 type1]
     proc play_sound {} {
       global sound1 len1 type1
       dive_readbuf_withMIME [dive_self] $sound1 $len1 $type1
     }
   }
 

1. Why can't I see some textures when using Linux-Mesa-3DfxVoodoo1?
    This might be because your textures are too large, 3DfxV1 based cards only support texture sizes up to 256x256 pixels.

2. Why do I have to be root when using Linux-Mesa-3DfxVoodoo1?
    This is because you need root access to be able to get register access to video hardware.
 

1. Why can't I use the stereo option on the render menu?
       Stereo is currently (DIVE 3.3x) only supported on SGI machines (shutter glasses needed).
 

1. Why isn't there a win95/98 version of DIVE?
    Unfortunately, DIVE cannot be used under Windows 95/98. The threads package that DIVE uses internally is incompatible with those versions of the operating system from Microsoft.
To get DIVE running on a PC, you will need to install Windows NT or Linux.

 Up to FAQ list

Dive contacts / dive-help@sics.se