system icon
VayTek's Homepage
View VoxBlast Rendering Times
Download Free Demo Software
VoxBlast General Information
VoxBlast for Macintosh
VoxBlast for Windows
VoxBlast for UNIX

VoxBlast Quick Reference Guide

fetus ultrasoundseismic image
3D Fetus and Seismic images created with customized VoxBlast software applications


Installing the VoxBlast Demo:

Windows: Place Disk 1 in drive or bring up the directory that contains the sub-directory DISK1. Use the Windows File Manager. Move to the appropriate drive and double click on SETUP.exe. Follow the instructions. If you're installing from hard disk, you do not change disks. Edit the path in the install dialog to DISK2 instead of inserting Disk 2. Do the same for Disk 3 and Disk 4. Double click the VoxBlast icon to run VoxBlast.

(If you have been provided with a single file instead of multiple disks for your Windows version of VoxBlast, the single file does not require the user to change the paths or diskettes as is required for multiple disks.)

Macintosh: Drag folder from disk to Desktop. Open folder. Double click on VoxBlast Demo.sea , then select Extract. Self extracting archive file will decompress.

Loading a Data Set: Select File from Main Menu. Select Load a Data Set... . Select an .fb file.
Creating and Editing a Data Set: (for working program only, not for demo) Select File from Main Menu, then Create a Data Set... or Edit a Data Set. Enter height and width of files, template name (* = non-zero-fill number, % = zero fills), start/ stop increment numbers, header length, byte info (8 or 16 bit, etc.), and interslice and interpixel interpolations. Save to a file with .fb extension
Rendering a Data Set: Click on the Render button on the main Control Panel.
View VoxBlast Rendering Times, comparing various platforms
Setting the Point of View:
  1. Place the cursor over the wireframe box icon in the Control Panel, click and drag on the icon. This will move the box and change point of view. New view is shown in the parameters window.
  2. Move the slicer bars in the Control Panel.
  3. Select a standard view from the Standard Views panel in the Control Panel.
Changing Rendering Speed - Data Set Parameters Click on Fastest Rendering (every 4th pixel), Fast Rendering (every 3rd pixel), Good Quality (every 2nd pixel), or Best Quality (every pixel). Fastest Rendering is 4 times faster than Best Quality.
Loading a Palette or Opacity Table Color palettes and opacity tables can be saved to disk. To reload them click on Palettes, then click on Load a Palette or Load an Opacity Table. Fixed palettes and tables can also be loaded from the Fixed menu.
Adjusting the Color Palette or Opacity Table: Click on Windows, click on Palette Editor. Palette editor window opens. Current palette is shown along top. Controls are on right. Editor window has red, green, blue and yellow (for opacity) lines in it. To change color palette, turn desired colors on or off with the buttons under the Edit column (leave the View column alone). Then use the mouse to redraw the chosen color in the edit window. Palette will be updated along top. Palette will be applied to image after it is rendered again. To change the opacity, turn all the colors off and the alpha on, then redraw the alpha line. The lower the alpha line the more transparent the corresponding pixel intensities; the higher the alpha line the more opaque the corresponding pixel intensities. Other commands let you switch from RGB to HSV mode, posterize (stairstep) the chosen line, copy and paste portions of the palette, or flip, smooth and linearize the line. Use the left and right mouse buttons to move and limit the usable area of the palette by moving the thin, red line at the top of the edit window just below the current palette display.
Viewing 2D Images:

Click on Windows, click on 2D Images. 2D image control window and 2D image window will open. Click on Resample. A green 2D plane will appear in the wireframe icon box in the Control Panel. This plane represents a cut through the volume. A cross section of the volume at the level of the plane will appear in the 2D image window.

Move the plane up or down in the volume and rotate the plane around any of the x, y, and/or z axes using the slider bars in the 2D image control window. Click on Resample to see the cross section at the level of the cutting plane.

Autosample updates the 2D image window each time a slider bar is moved. This can cause a lag in program operation on a slow computer. Leave Autosample off in most cases.

Arbitrary Plane lets you set the cutting plane to any arbitrary angle. Slice Plane forces the cutting plane to be parallel with the orthogonal views.

Set Bias, Interslice, dx and dy are settings for creating a new data set that is written to disk. The slices in the new data set are created by passing the cutting plane through the volume at an arbitrary angle. The arbitrary angles become the orthogonal angles in the new data set. See the Users Manual for more detail on how to use this feature.

The Tracing functions control the tracing in the 2D and 3D image windows. Trace color is controlled in the Trace box on the right that has the default color of Red set. Traces are cleared in the Clear box with the default clear color of Red set. You can save and load trace points using the Save and Load functions.

Save Surf saves a defined surface on the 3D projection in the 3D window. The surface is saved a polygonal data set and can be rendered using Polyrender. See Polygon Rendering for more detail.

Isocontour sets a threshold level in the 2D image window. To use, turn Isocontour on, then move slider bar to the right. The threshold value appears below the slider bar. Click on Resample. The 2D image will be redrawn. All pixels below the threshold value will be drawn in red. All points above the threshold value will remain in grayscale. VoxBlast will Autotrace in this mode. To Autotrace, place the cursor in the 2D image window to the right of the area to be Autotraced and click once on the left mouse button. VoxBlast searches to the left until it finds an area above threshold, then detects the edge of the object and traces it.

Clip Points is used with tracing points on the 2D and 3D images. To use, 1) click on Render, 2) click on Resample, 3) click on Isocontour, 4) move Isocontour slider bar to at least 100, 5) click on Resample, 6) set trace color to Blue, 7) put cursor to right of grayscale area and click once - this will autotrace around a section of the heart in blue, 8) the trace on the 2D image will simultaneously appear in the 3D image window, 9) click on Clip Points. Clicking on clip points will alternatively show and hide the points on the 2D image plane as they pass behind the 3D volume using a hidden line algorithm.

Measurements:

Click on Windows, click on Measurements. Measurements window will open. Set trace color to match the currently active color in the 2D Image Control Window (IBM AT: click on Options, click on Trace Color; Macintosh: click on Red). Trace points on 2D or 3D image. (IBM AT: click on Recalculate). Measurements will appear in window. Measurements shown are:

  1. X, Y, Z and value of last point clicked
  2. Linear distance between last two points clicked
  3. Angle between last three points clicked
  4. Total distance of all points clicked (i.e., perimeter), and surface area of area traced (IBM AT: click on Surface Area)

Measurements on 2D image are flat, linear measurements. Measurements on 3D image are true 3D measurements on surface of volume. You can save the measurements to disk as an ASCII text file. Click on Copy, then click on Save.

Lighting Model:

There are two lighting models: post light and intrinsic. Post light is faster but is subject to noise; intrinsic is slower but less sensitive to noise. To use the post light model:

  1. Click on Render with Best Quality,
  2. Click on Filters
  3. Click on Zbuffer Average or Median
  4. Click on Windows
  5. Click on Lighting Model
  6. Set the angle of light by dragging in the square in the upper left corner
  7. Set the intensity of light by using the slider bar at the top of the window
  8. Click on Postlight

To change the lighting settings, click on Edit, click on Undo, change the settings, then click on Post Light.

To use the intrinsic model, click on Intrinsic in the Lighting Model window and make the appropriate settings. You can set the voxel intensity with the intrinsic model but not with the post light model. Click on Render. The lighting model is applied to each voxel as it renders.

Filters: You can apply filters to the 3D image or to the z buffer. Zbuffer filters are used in conjunction with the post light lighting model. To apply a filter, click on Utilities, (Macintosh: click on Edit) click on Filters, select filter.
Save/Load Settings: You can save and load the current settings (rotation, cutting plane, background color, etc. Click on File, click on Save or Load, enter the appropriate file name.
Plot Window: The Plot window shows the histogram or the profile of a line drawn on the 2D or 3D image. Click on Windows, click on Plot Window. Draw a line on the image. Select Histogram or Profile. Turn Integration on or off.
Image Background Color: You can change the background color of the 3D image. Click on Utilities (Macintosh : click on Edit), click on Background Color. A window appears that allows you to change colors with slider bars. You can work in RGB or HSV mode. Select a color. It will be applied when the image is rendered again.
Movie Generation and Playback:

To create a movie loop: click on Utilities (Macintosh: Options), click on Movie Generation. The Movie Generation window will appear. The movie will begin at the current rotation of the data set. To have the movie begin at a different point, change the values under Offset. The movie will progress through an angle of elevation and azimuth (vertical and horizontal). Set the values in under the Length column. Next set the number of frames in the movie loop. Total length divided by # of frames gives the degrees between each frame. Give a name for the movie in the Template window. Next select the options that are to be turned on or off during movie generation. Script Only means that the script for the movie will be generated, but the movie will not. No Playback means the movie will be generated, but it will not be automatically shown when generation is complete.

To playback a movie: Run the Movie program, click on File, click on Load a Movie, select movie. Movie will playback.

Resampling a Data Set: A data set can be resampled to make it smaller or larger, or to remove volume of interest from the original volume. This can speed the rendering. To resample a data set click on Utilities (Macintosh: Options), click on Resample a Data Set. Resampling window will appear. Wireframe rectangle shows current dimensions of a single 2D slice from data set. Define the region in the current data set to be resampled by entering values for Top, Left, Source Width and Source Height. Define the size of the output data set by giving the Output Width and Output Height. Use the Filter option to smooth aliasing from odd sized interpolations. Click on Resample to start process.
Cutting Plane: You can place a cutting plane in the volume and use 2 color palettes and 2 opacity tables - one for each side of the plane. This can produce dramatic results in a movie loop. To set a cutting plane, click on Windows, click on Lighting Model. The Lighting Model window will appear. The controls for the cutting plane are at the bottom of this window. Click on Plane On. Use the slider bars to set the angle of the plane. The plane will appear in the wire frame icon box in the main Control Panel. Load a color palette in voxel right and a different palette into voxel left from the Load Palette option, then render the image again.
Ortholimit Planes: Ortholimit planes creates a subvolume of the volume along the orthogonal limit planes. To use the feature, click on Utilities (Macintosh: Options), click on Ortholimit Planes. Use the slider bars to set the orthogonal limits along the x, y, and z axes. A preview of the cutting plane appears in the thumbnail window. Click on Render to see the results. All voxels outside the limit planes are ignored and rendering will be proportionally faster.
Image Magnification and Pixel Tracing Size: To magnify the 2D or 3D image or increase the pixel tracing size, click on Options in the 2D or 3D image window (Macintosh: click on Windows), and select the appropriate option, then set the desired magnification.
Autosegmentation and Flood Fill:

The Autosegmentation feature lets you seed an object and have VoxBlast fill the volume with a color and calculate the volume of the object. This feature requires skilled use of the Palette editor, 2D Images, the 3D Image window and the Autosegmentation window. You should consult the User's Manual before proceeding with this feature. In summary, to use this feature you need to:

  1. Define the area to be flood filled using the isocontour feature
  2. Prep the voxel and 2D image palettes
  3. Redraw the color and opacity tables for the new palettes
  4. Explore the volume to check for 'leaks'
  5. Tag points to plug leaks, if necessary
  6. Apply some seeds to the volume
  7. Autosegment
  8. Render and check the volume
  9. Repeat the process to fine tune the autosegmentation
Command Line and Play a Script: VoxBlast can accept input from the window menu commands, the command line, or an ASCII text file script. To open the command line, click on Windows, click on Command Line. To see the valid commands, type Help. To submit a script, create an ASCII text file containing valid VoxBlast commands, click on File, click on Play a Script, enter the text file name.
Tracing Functions: See Viewing 2D Images
Coordinated 2D and 3D Image Windows: VoxBlast has coordinated 2D and 3D image windows. Any trace in either window automatically appears in the appropriate location in the other window. This aids in the precise exploration and measurement of volume data sets. This feature is automatic. For more details see '2D Images' or consult the User's Manual.
Surface Extraction and Polygon Rendering: . VoxBlast lets you extract a surface from the 3D volume as a polygon data set. The extraction can be done in 2 and 1/2 D or in full 3D. The extracted data set can be imported to a CAD program, or rendered in VoxBlast. The surface can be polyrendered by itself, or overlaid on top of a voxel data set. This allows you to merge two data sets together, e.g., a PET scan and an MRI scan. To extract a surface, see '2D Images'. To render a polygon data set, click on Windows, click on Polyrender, click on Add an Object, select the data set to be rendered, click on Polyrender.
Suggested System Requirements:

Windows 95/NT computer with Pentium or better; minimum of 32 Mb of RAM (larger data sets may require additional RAM), SVGA graphics card or better, a monitor with at least 800X600 resolution displaying a minimum of 256 colors. A hard disk with at least 50 Mb of free space.

Macintosh: PowerMac 603e or better, minimum of 40 Mb of RAM (larger data sets may require additional RAM), Monitor graphics with at least 800X600 resolution displaying a minimum of 256 colors. A hard disk with at least 50 Mb of free space.