Volume Viewer Settings

Use Volume Viewer to look at the all or part of your data in 3-D. You can view the data interactively (where you change the viewing angle using the cursor in a window) or as a movie (where you specify a rotation path and generate movie frames).

Open Volume Viewer by choosing View | Volume Viewer from the main softWoRx menu.

Volume Viewer Input, Subset Z, and Wavelength Scaling Fields

Use

To...

Input, Output, Select region, Reset, Details

Specify input data and output parameters as shown in Image Input and Output.

Subset Z

Open the Section Subregion dialog box and specify the Start and End Z section for each wavelength of the data that is loaded. you can choose to render a different set of Z sections for each wavelength.

Wavelengths

Choose which wavelengths to work with. Movie projections are created for all of the selected wavelengths. The Interactive method can only display one wavelength at a time but if you select more than one wavelength, you can toggle back and forth between the wavelengths to display each one.

Wave
<wave#> Scale

Set the Minimum, Maximum, and Exponent for each of the wavelengths to be rendered. The default values are those currently being used to display the input image.

Note If you scale the intensities of the Input window, these scale factors are updated. Then, when you choose Do It to create a series of movie frames, the data is automatically reloaded with the latest scale factors.

 

Viewing Parameters Fields

Use

To...

Method

Choose one of five rendering method options:

Method

Description...

Additive

Summation of all the voxels touched when a single ray projects through the volume.

Maximum Intensity

The maximum intensity found when a single ray projects through the volume.

Progressive

projects a ray from the back to front and excludes pixels behind as the pixels in front cover them up.

RGB/Opacity

Using extra opacity information generated from Blend Colors, this method can be used to volume render a color-blended multi-wavelength image realistically.

Volpak

Generates images that use lighting techniques to highlight surfaces in the 3D rendered image. This method is substantially faster than the other methods supported, although the method may not be optimal for all image types.

 

Note VolPack uses libraries obtained from the Stanford Computer Graphics Laboratory. It  is an implementation of the shear-warp volume rendering algorithm as described in Lacroute, P. and Levoy, M., Fast Volume Rendering Using a Shear-Warp Factorization of the Viewing Transformation, Proc. SIGGRAPH 1994, ACM.

Mixed...

Allows you to assign different rendering methods to different wavelengths.

 

Quality

Choose from 3 Quality settings:

  • Good - Very fast rendering; no interpolation between Z sections.

  • Better - Moderately fast rendering; some quick interpolation between Z sections.

  • Best - Slowest rendering; optimal interpolation between Z sections.

Z Resolution

Adjust the Z Resolution parameter. This gives you the ability to do a quicker rendering at the expense of detail in the Z direction. The default value of Best considers each Z section in the rendering. Values of High, Medium, and Low indicate less and less detail but faster rendering performance.

Movie Method: Increasing Z or XY Sampling creates movie frames with more coarsely sampled data.

Original Size

Specify that the output image is the same width and height as the input image. If the image is being rotated, you may find that parts of the image are clipped.

 

Movie Options

The Volume Movie Maker lets you create a sequence of volume rendered image frames with a specified rotation change. This rotation can be around any axis and any angle.

Use

To...

Start Angles

Specify an axis of rotation as follows:

  • X:  Positive X rotates about a horizontal axis so that the top of the image is rotated toward your eye and the bottom of the image is rotated away.

  • Y:  Positive Y rotates about a vertical axis such that the left side of the image is rotated toward your eye and the right side is rotated away.

  • Z:  Positive Z rotates around an axis normal to the computer screen in a counter-clockwise direction.

Number of Projections

Specify the number of projected image frames for the movie.

Rotation

Choose from a number of pre-configured rotation schemes or choose Custom to specify change angles in X, Y, and Z.

Status

View the progress of loading the data into memory and generating movie projections.

 

  Buttons

Use

To...

Done

Close the Volume Viewer.

Do It

Start generating movie projection frames for the output window or file. If parameter changes (e.g., intensity scaling, region selection) require the data to be re-loaded , it is reloaded automatically.

Interrupt

Cancel either the current data loading or movie generation.

Interactive

Open an image in a temporary Image window along with the Interactive Image dialog box. You can rotate the image by clicking and dragging the cursor with the left mouse button down. Because the calculation of the image may take a long time, you may choose to change the Z Sampling or the XY Sampling to reduce the calculation time while you're moving the cursor. When you release the left mouse button, the image is re-drawn at full resolution.