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Erase operator attributes menu item

This item pops up a window which allows you to set operator attributes for erase operators. If you select a plot that has an erase operator applied from the Active plots list in the MeshTV Main window, then anything you change and apply will affect selected plots. Plots not highlighted will not be changed, unless Apply operators to all plots toggle button is on, in which case all plots will be changed. If you select this item without selecting a plot first, and you try to apply changes, a Query window will pop up asking if you want to add an erase operator so you can apply the changes you have made. Note that if you make changes in this window and then select a plot that has an erase operator applied, your changes will be lost.

You can modify the default settings for attributes for future operators by pulling up this window, making your changes, and pressing the Make default button. This affects only operators applied in the future, not already applied ones, and stays in effect only for the remainder of the current MeshTV session unless you also select Save settings from the File menu.

Erase attributes window

The Erase attributes window looks like Erase attributes , if you are using MeshTV's defaults. If you aren't, the values might be different.

This window allows you to set the attributes assigned to existing or future erase operators. The window includes controls to manage the intersection of up to 6 spaces.

The erase operator allows the erasure of a 3D region formed by intersecting up to 6 regions, each specified by the volume on one side of a plane. (This operator works only for 3D data files.)

A single plane eliminates the region on one side of a plane. Two planes eliminate a wedge shaped region. For example, using two planes that pass through the center of the viewing volume, oriented at 90-degree angles to each other eliminates, 1/4 of the viewing volume. Three planes eliminate a three-sided wedge region. Using three planes that pass through the center of the viewing volume, oriented at 90-degree angles to each other, eliminates 1/8 of the viewing volume.

The planes are positioned using the longitude, latitude, and radius settings.

If you don't see a description for an item in this window, check in the Shared items section near the front of the chapter.

Plane option menu

Select the plane whose attributes you are setting by selecting the corresponding number from this option menu. The values range from 1 through 6.

Status radio buttons

This determines if a given plane is active. When you change the plane number via the Plane option menu , these radio buttons update with the status for that plane.

Longitude slider bar and text field

To position the erase plane, imagine that the object sits in space with the default 3D view where the positive Z axis points out of the screen, the positive X axis moves from the left to the right of the screen, and the positive Y axis moves from the bottom to the top of the screen.

The longitude control rotates the plane about the Y axis and can vary in value from -180 degrees to +180 degrees. Specifying a positive angle rotates the plane in a counter-clockwise fashion, when looking down on the Y axis.

You can either type your value into the text field, or use the slider to select a value.

Latitude slider bar and text field

To position the erase plane, imagine that the object sits in space with the default 3D view where the positive Z axis points out of the screen, the positive X axis moves from the left to the right of the screen, and the positive Y axis moves from the bottom to the top of the screen.

The latitude control rotates the plane about the X axis and can vary in value from -90 degrees to +90 degrees. Specifying a positive angle rotates the plane in a clockwise fashion, when looking down on the X axis.

You can either type your value into the text field, or use the slider to select a value.

Radius slider bar and text field

To position the erase plane, imagine that the object sits in space with the default 3D view where the positive Z axis points out of the screen, the positive X axis moves from the left to the right of the screen, and the positive Y axis moves from the bottom to the top of the screen.

The radius control moves the plane in and out along the direction specified by the longitude and latitude values. The radius can vary from -100 to +100. A value of 0 positions the plane at the center of the viewing volume. A positive radius moves the plane in the direction specified by the longitude and latitude values, while a negative radius moves the plane in the direction opposite the direction specified by the longitude and latitude values. A value of 100 corresponds to 1/2 the distance between any corner of the viewing volume and its opposite. This means the a value of 100 is guaranteed to be outside the volume and that a value between 0 and 100 may or may not be within the volume depending on the orientation of the plane.

You can either type your value into the text field, or use the slider to select a value.

Offset text field

When a non-zero offset is specified, the region specified by the planes is not removed from the problem, but is offset instead by the specified value in the direction derived by averaging the perpediculars to each plane.