Blood Flow Manual

Usage

Basic Usage

The Blood Flow plug-in comes with two data sets: Aneurysm & Fontan. To add another data set to the plug-in, refer to the "Adding New Data" section. The Aneurysm data set is considerably smaller and thus will load much faster. It is the recommended data set when loading in the StarCAVE. After selecting the data to load, click "View All" to position the data in your field of view.

The plug-in can display two elements at the same time: one surface data set and one "tracer" data set. For example, when loading the surface, you can decide on an animated surface or a static surface. An animated surface will move or pulse, while a static surface will remain stationary. Although an animated surface is generally the preferred display mode, a static surface will load considerable faster and thus might be preferred when time constraints are present.

Surface Options

You may notice that there are three options of surfaces for the two data sets: displacement, pressure, and velocity. All of these options determine the colors of the surface. Selecting "displacement" will color the surface based on how much it moved from the original position. A patch of blue would indicate little to no movement, a patch of green would indicate moderate movement, and a patch of red would indicate considerable movement. The coloring scheme is determined by the data set, although both the Aneurysm and Fontan data sets use the blue -> teal -> green -> yellow -> red coloring scheme. Selecting "Pressure" will use the given coloring scheme to indicate how much pressure is occurring on the surface. Selecting "Velocity" will use the Euclidean norm of the velocity vectors on the surface nodes to color the surface.

Tracer Options

There are three tracer options for the two data sets: Pathlines, Streamlines, and Velocity Vector Field. The names are self-explanatory. You can load any of them alone, or you can view them with a surface (static or animated). Make sure that your surface and tracer data correspond (i.e. they both start with either "Aneurysm" or "Fontan").

Other Options

Quality Percentage

Selecting a percentage that's less than 100% will gracefully reduce the vertices of the model in order to enhance run-time performance. Keep in mind that lower percentages will result in longer "optimizing" times during loading.

Transparency

The "transparency" option will indicate the opacity of the surface. 1 indicates complete opacity, while 0 would indicates complete transparency.

Enabling Blood Flow plug-in in OpenCover

If "Blood Flow" does not appear as one of the options in the OpenCover menu, you will need to enable it. Open the "covise/config/starcave.xml" document and find the line that states <Bloodflow value="off" />. Change the "off" to "on" and restart OpenCover. "Blood Flow" should now appear in the OpenCover menu.

Adding New Data

Data is automatically loaded from the "/home/covise/data/Bloodflow/" directory. The plug-in supports most data exported from the COVISE Map Editor. Although comprehensive usage instructions for the COVISE Map Editor is beyond the scope of this manual, minor instructions are included for those familiar with the map editor.

In order to export the data, use the "WriteASC" IO_Module in the Covise Map editor. Generally you have a "Collect" module in your map that takes grid/geometry data as the first input and color data as the second input. Instead of connecting these to the "Collect" module, connect the geometry data to a "WriteASC" module and the color data to another "WriteASC" module. Run the map editor and name the outputted geometry data as "surface" and the outputted color data as "color". Now that you have the necessary data, place them together in a folder (you folder name will appear in one of the sub-menus). Place that folder in either the "AnimatedSurfaces", "Lines", or "Surfaces" folder in the "/home/covise/data/Bloodflow/" directory. If you place it in the "Surfaces" folder, your data will appear under the "Static Surfaces" sub-menu; placing it in the "AnimatedSurfaces" folder will cause it to appear in the "Animated Surfaces" sub-menu, and placing it in the "Lines" folder will cause it to appear in the "Tracer" sub-menu.