Mode Menu

Mode Menu

Grid Wireframe

selects the data to be drawn as a wireframe model.

Grid Wireframe Hidden Line Removal

will remove the parts of the wireframe that are obscured by other parts of the wireframe.

Grid Triangle Mesh

draws the model as a uniform grid wireframe mesh of triangles.

Grid Gouraud Shaded Gray

selects the data to be drawn a shaded, lighted gray surface.

Grid Texture Map

uses the image data to draw a textured model.

Grid Texture Map with Lights

adds lights to the Texture Map mode.

Grid Gouraud Shaded

draws the model using Gouraud Shading.

Grid Gouraud Shaded with Lights

adds lighting to the Gouraud Shaded mode.

TIN Wireframe

draws the selected Triangulated Irregular Network as a wireframe model.

TIN Gray Surface

draws the selected TIN as a shaded, lighted gray surface.

TIN Texture

draws the TIN as a textured model.

TIN Texture

Lighted draws the TIN as a textured and lighted model.

TIN Gouraud Shaded

draws the TIN using Gouraud Shading.

TIN Gouraud Shaded Lighted

adds lighting to the Gouraud Shaded TIN.

Show View Dependent Tiles

shows the tiles as a red and white checkerboard pattern with the index of tile.

Create TINs

brings up a dialog to allow the user to create Triangulated Irregular Networks. See below.

Select TINs

is a pull-right menu that allows the user to select one of the available TIN models.

Cross Product

is an option used during development to view the points selected by the cross product point selection method.

Peaks and Valleys

is an option used during development to view the points selected by the Peaks and Valleys point selection method.

Wireframe

draws a wireframe on the model's surface in all but wireframe modes. This option does not currently work correctly in Gouraud Shading with Lights.

Stereo

mode will toggle between "stereo-in-a-window" and non-stereo mode when "stereo-in-a-window" has been enabled. See the section of this document titled stereo for more information.


Create TINS

create tins

The Create TIN Dialog allows the user to create a triangulated irregular network using the currently selected point resolution. These points can be chosen using one dimensional methods (which pick points along each row and column) or by using a two-dimensional method.

When a one dimensional method is used, the points will be selected and a dialog will appear telling the user how many points were selected prior to creating the triangulation. This allows the user to reselect points if the number is not satisfactory.

After a triangulation has been created with either the one or two dimensional methods, a dialog box will appear that allows the user to name this triangulation. This name will then appear in the Select TINs menu. If the header file is saved, this name will also be used to save the triangulation.

Multiple options can be selected and the algorithm will continue until all paramaters have been satisfied.

One Dimensional Point Selection

Selecting its checkbox enables the one dimensional methods for selection.

Douglas Puecker

This one dimensional point selection method picks points along each row and column using a technique similar to the Douglas Puecker curve fitting algorithm. The text box next to this option is for a value that determines how far a point must be from a line to be selected as significant. These values must be picked via trial and error for each data set.

Cross Product

This one dimensional point selection method picks points along each row and column by looking for the changes in the sign of cross products formed by each group of three adjacent points.

Peaks and Valleys

A peak is a point that is higher than its two adjacent neighbors and a valley is a point that is lower than its two adjacent neighbors. The text box allows subsets of peaks and valleys to be selected. "1" will select all peaks and valleys. "2" will select peaks and valleys from set "1" and so on.

Two Dimensional Point Selection

Selecting its checkbox enable the two dimensional method for point selection. For each parameter a percentage is show at the right side of the dialog that updates as the value in the text box is changed.

Average Error

If this item is enabled the mesh generating algorithm will not stop until the average error of all points is less than the specified value.

Maximum Error

If this item is enabled the mesh generating algorithm will not stop until the point with the maximum error has an error value less than the specified value.

Average Vertical Error

If this item is enabled the mesh generating algorithm will not stop until the average vertical error of all points is less than the specified value.

Maximum Vertical Error

If this item is enabled the mesh generating algorithm will not stop until the point with the maximum vertical error has a vertical error value less than the specified value.

Number of Polygons

If this item is enabled the mesh generating algorithm will stop when the number of polygons is greater than or equal to the specified value.

Number of Vertices

If this item is enabled the mesh generating algorithm will stop when the number of vertices is greater than or equal to the specified value.

Retriangulation Method

After the points in the simplified mesh are determined, the mesh is retriangulated using either the Delauny triangulation method or a Semi-Delauny triangulation.


Jeremy Hinegardner
Last modified: Sat May 22 15:05:12 CDT 1999