Usage : Features : Download : Internals : Related
Thrup’ny is a free, open-source multi-platform viewer for VRML 3-D models, designed for both anatomy teaching and finite-element pre- and post-processing.
Quick start: Use
.wrl file, then
click and drag to manipulate the model.
Use the Esc key to switch between
the viewing and pointing modes.
To view VRML models with a Web browser, configure your browser
to use Thrup’ny as a helper application for
^O] to open local files; the default directory is taken from the most recently opened file (if any) or from the
HOMEenvironment variable (if any), or is the root directory. Remote files can currently be opened only by typing an exact URL into the text-edit box.
^R] to render the current view into an image file (a
.rgbfile in the same directory as the model). (It may be necessary to decrease the level of graphics hardware acceleration to make this work under MS Windows.) The
.rgbfile can be converted to other formats using, for example, ImageMagick:
convert -geometry widthxheight name.rgb name.png. The
heightparameters specify the size of the Thrupn’y display area in pixels. The size can be set using .
Shift-^R] to render a set of views into image files. Dialogue boxes come up asking how many rotation steps to make about the x and y axes. The set of image files can be used to create an interface like the one here. The files can also be used to create an animation; for example,
convert -adjoin -geometry width -delay ticks *.rgb animation.gif.
HKEY_CURRENT_USER ► Software ► AudiLab ► Thrupny)
^S] for fast but ugly rendering of transparency
^B] for prettier rendering of transparency that may be slower and may also display some structures at the wrong depth
^C O] for a camera with no perspective adjustments, so parallel lines stay parallel
^C P] for a normal perspective camera
In the list above, the underlined characters are accelerator keys,
invoked initially using the
denoting a control key, that is, holding down the
key while pressing the indicated key. Note that the shortcut keys
involve pairs of keys in some cases, such as
P to invoke a perspective camera.
Esc (Escape) key can be used to toggle between the
viewing mode and the pointing mode:
To change the centre of rotation,
S key and then
left click on some structure within the model. The view will zoom in
on that structure, which will be centred in the window and will
become the centre of rotation. (After this, the displayed orientation
will no longer be correct; this is a bug.)
After the model has been rotated
by means of the thumbwheels or buttons,
the current orientation is displayed in the status bar
as a set of 3 rotations, in degrees,
corresponding to sequential rotations about the z,
y and x axes, in that order. If the rotation
is performed by dragging the model itself, the displayed orientation
is not automatically updated; it can be updated at any time by
(Here I do not distinguish between zooming, for an orthographic camera, and dollying, for a perspective camera).
(This only works for objects which are ‘children’ of VRML ‘anchor’ nodes. The goal is to use right clicking for pointing, rather than having two separate modes. For now, right clicking on the display will bring up a menu for adjusting various things; this menu is not meant to be used, and some of its functions are not enabled.)
The toolbar contains two dropdown lists, one for locations (URL’s) and one for viewpoints. For each, a check-mark button can be used to invoke the currently displayed item.
To invoke a URL, select it from the Location drop-down list so it
is displayed in the box, or type a new one into the box, and then
press the check-mark button (or press the
The Viewpoints list displays the names of any viewpoints that are predefined in the model definition. A viewpoint can be invoked by highlighting it in the drop-down list. To return to the last-selected viewpoint (the name of which is currently displayed in the Viewpoints box) click on the check-mark button.
The items in the list above have been implemented or partially implemented, or have not yet been implemented.
Thrup’ny is licensed under the GNU General Public Licence. If I am not properly complying with the GPL, please let me know.
GPL implies that the source code is available, but it is not linked to on this page – contact me if you want it.
Thrup’ny for Windows consists of an executable file,
thrupny.exe, and several DLL files.
Below are downloads of the files in three alternative forms.
Once you have all of the files in a single directory
thrupny.exe to run it.
Create a shortcut in the Start menu or elsewhere if you wish.
Download this file into some folder then double-click on it. It will extract the Thrup’ny executable and the DLL's into the folder that it's in.
Download this .zip file and
use an Unzip utility to extract
and the DLL's into some folder.
Download all of the following files into the same directory. The DLL files are local copies of required third-party libraries, for convenience; they are all subject to the GPL or similar licences.
thrupny.exein order to upgrade it.
Download thrupny.zip and extract its contents into some directory.
and each of the required
lib* files (see below)
to wherever you like, as long as they're all in the same directory.
cd to get into the directory where you have stored
the files and do
chmod u+x thrupny* to make
The latter is a script
thrupny to look in its own directory for its libraries.
To run Thrup’ny, use
cd to get into the directory
where you have stored the files and do
Names starting with
Q are from QT,
those starting with
So are from Coin3D.
The C++ source files include:
thrupny.cpp: The main programme, consisting of just a few lines to establish the QT application object; call
thrupny_window.cpp); and enter the main event loop.
thrupny_loader.cpp: Called by
thrupny_viewer.cppto set up a VRML
thrupny_viewer.cpp. I'm not really clear about how this works.
getOrientation()to compute equivalent rotation values corresponding to current view.
osRenderMult()to render to
thrupny_window.cpp: Set up Thrup'ny window with central widget, actions, menus, toolbars, status bar, spin boxes, thumbwheels. Implement functions for displaying orientation, displaying messages and object labels. Implement
Thrup’ny is based on the GPL versions of Coin and SoQt and Qt. It is being developed under Debian GNU/Linux and MS Windows and should be portable to other operating systems.
Since 2011, Coin3D has been purely non-commercial and is hosted at bitbucket.org/Coin3D.
Thrup’ny is based in part on code and advice generously provided by Sylvain Carette.
floatableproperty so they also can now be undocked. However, a difference remains in that Qt Designer 4.4 will add only actions to a toolbar, although widgets can still be added outside Qt Designer, using
addWidget(). Another difference is that dock windows have title bars but toolbars don’t. The dock-window title bar can be modified (or removed [?]) using the setTitleBarWidget() function (introduced in 4.3) and the space it takes up can be reduced using the DockWidgetVerticalTitleBar feature. Also note the following in the documentation for version 4.4: ‘When a QToolBar is not a child of a QMainWindow, it [loses] the ability to populate the extension pop up with widgets added to the toolbar using addWidget(). Please use widget actions created by inheriting QWidgetAction and implementing QWidgetAction::createWidget() instead. This is a known issue which will be fixed in a future release.’ [ref]