Module: Ortho Slice ()

Description:

The Ortho Slice module is an important tool for visualizing scalar data fields defined on uniform Cartesian grids, e.g., 3D image volumes. Such data are visualized by extracting an arbitrary axis-aligned slice out of the volume. The data values can be mapped to colors or gray levels by one of two mapping methods. A contrast limited histogram equalization technique may be applied. With this method, there is no unique correspondence between gray levels and data values any more. The method tries to visualize all features of an image. As a third mapping method, an external colormap can be used in Ortho Slice.

The Ortho Slice module is also capable of extracting slices of an RGBA color field or of a 3D multi-channel field. In these cases the slices are displayed as is and no mapping method need to be chosen.

Connections:

Data [required]
The 3D field to be visualized. Currently, regular scalar fields, multi-channel fields, and RGBA color fields with uniform or stacked coordinates are supported.

Colormap [optional]
Optional colormap used to map scalar data to colors. This port is hidden when Histogram mapping is selected. See also Colormap.

Ports:

Orientation

This port provides three buttons for setting the slice orientation: xy perpendicular to the z-axis, xz perpendicular to the y-axis, or yz perpendicular to the x-axis.

Slice Number

This slider allows you to select different slices. The slices may also be picked with the mouse and dragged directly in the 3D viewer.

Channels

This port is displayed if the module is attached to a 3D multi-channel object. It allows you to toggle individual channels on or off. Each channel is mapped using a linear intensity ramp. The data window for each channel can be adjusted in the multi-channel object itself.

Mapping Type

Mapping Type

This option menu lets you select between the two different mapping methods, namely Histogram equalization, and Colormap mode. The port is not available if the Ortho Slice module is connected to an RGBA color field or to a 3D multi-channel field.

Contrast Limit

This port is displayed if Histogram equalization is selected. The number determines the contrast of the resulting image. The higher the value, the more contrast is contained in the resulting image. A value of zero means that contrast will not be limited at all.

Colormap

Choose colormap if mapping type is set to Colormap.

Display Options

Options

If the adjust view toggle is set, the camera of the selected viewer is reset each time a new slice orientation is selected. The bilinear toggle determines how color is interpolated within a slice. By default, the toggle is off and constant interpolation is used. With constant interpolation individual pixels become visible. Bilinear interpolation often produces somewhat blurry results. Checking the lighting option simulates the slice being illuminated by a headlight. Thereby, the intensity of the slice is modulated according to the direction of the slice's normal. Thus, the more obliquely the slice is viewed the darker it becomes.

Frame

This port is used to display or hide the frame, set the frame width and color.

Transparency

This radio box port determines the transparency of the slice. None means that the slices are fully opaque. Binary means that only fully transparent parts are transparent while others are fully opaque when using colormap mapping. Alpha means that opacity is proportional to luminance. If a colormap is used for visualization opacity values are taken from there.

Alpha

This port is displayed when using an alpha transparency on a Histogram equalization mapping type. Thanks to this port, you will be able to select the minimum and maximum opacity values.

Embossing

Embossing

This port enables a bump mapping visualization of the slice.

Depth

This port is displayed only when option embossed is checked. Factor controlling the bump mapping visual depth effect.

Commands:

createImage <image base name>
This command creates a 2D image and adds it to the Project View. The image base name can be omitted.