tri_tool is an MVS module primarily for use with surf_cut. It can subdivide triangular and quadrilateral cells until none of the sides of the output triangles exceed a user specified length (a default value is calculated as 5% of the x-y extent of your input surface). This increases the accuracy of surf_cut especially when the input surface comes from scat_to_tin and the nodes used to create the TIN are poorly spaced. It can also correct the normals of a surface. It does this by organizing all of the triangles and quadrilaterals in a surface into disjoint patches, and then allowing the user to select which patches have normals that need to be flipped. The maximum number of triangles in a patch is 130,000, any triangles above this number will be considered to be in the next patch.
Module Input Ports
tri_tool has one input port which accepts a surface composed of triangular and/or quadrilateral cells.
Module Output Ports
tri_tool has two output ports.
The first port outputs a surface consisting of the newly created or flipped triangles.
The second port outputs a renderable surface to a Viewer. This surface consists of triangles that are colored according to the disjoint patch they belong to.
Module Control Panel
The control panel for tri_tool is shown in the figure above.
The Remove Coincident Nodes toggle is used to merge nodes that have multiple nodes occupying the same coordinate space.
The Split Cells toggle is used to ensure that none of the triangles have an edge longer than the maximum edge length.
Display Lines toggles the line rendering mode between Regular and None. This displays the connectivity between nodes for each cell.
The Remove Cells Smaller than toggle is used to remove extremely small cells (based on area in your coordinate units squared) that sometimes are generated with CAD triangulation routines that might have their normal vectors reversed and would contribute to poor cutting surface definition. Try this option if you find that surf_cut is giving anomalous resuts.
The Maximum edge length type in allows the maximum length of each triangle side to be set for when the Split Cells toggle is set.
The Fix Normals toggle is used to check to make sure all of the triangles in selected patches of the surface have the same normal. If the normal is backwards, you can flip the normal of the patch in two ways. The first way is Alt + Right click on a cell in the patch that you wish to flip and then click the Add patch to flip list button. You only need to do this for one cell in each patch. Another way to do this is to increase the num to flip slider by one and enter the Cell Id and Cell Data value of a cell in the patch you wish to flip. The Cell Id and Cell Data values should be gotten from the surface being output from tri_tool, and not the surface being input.
The Culling Mode toggle controls whether back facing surface are visible. Generally you will want this ON when making the object(s) transparent.
The Transparency slider determines the opacity of the objects.
Module Status: Interruptible
This module's computational processes can be terminated (interrupted) using the "C Tech" icon in the Windows Notification Area (aka System Tray) in the lower right corner of your desktop. If you hover over the icon, it will tell you the status of the module and expected completion time. Double-Right-Clicking will terminate the process. Note that if you do stop any process, the output of the module is corrupted and any downstream module's results are not usable. You will need to re-run the module.
