The “Drawing” interface has two special functions: Managing the surface's graphical elements and managing triangulation.
In the "Draw/Erase" section, you can draw and erase various elements connected to the surface.
Button | Description |
|---|---|
Points | Draws or erases all the points on the surface. |
Outline | Draws or erases the designated outline from the surface's "Outline" tab. This line's settings may be changed in preferences. |
Lines | Draws or erases all of the breaklines from the surface's "Lines" tab. These lines' settings may be changed in preferences. |
Triangles | Draws or erases all the triangles included in the "Triangles" tab as individual faces. If there are no triangles present in the tab, the function is grayed out. These triangles' settings may be changed in preferences. |
The "Preview" button is used to view the surface once the points have been loaded. After triangulation, it is also possible to view the natural surface and the triangulated surface. Some keyboard shortcuts exist to manipulate the preview.
Here is a list of the "graphical preview" viewer shortcuts:
Shortcut | Description |
|---|---|
Z | Recenters the drawing so it can be seen in full. |
T | Shows/hides the surface as a solid color (seen on left). |
F | Shows/hides the triangle segments (seen on right). |
P | Shows/hides the surface's points. |
L | Shows/hides the breaklines. |
The second section, triangulation, is used to manipulate the surface's outline and triangle tabs as a whole.
Button | Description |
|---|---|
Triangulate | Used to triangulate the surface by the Delaunay method, with the points, breaklines, holes, and outline saved. It is important to ensure that the surface is valid before triangulating in order to avoid a conflict in triangulation. Two options are available:
|
Make outline | Used to generate an outline around a triangulated surface. The "Max. Edge Length" option is used to determine the maximum length that an outline segment can be. |
Edit triangles | Used to switch two contiguous triangles so that their shared base passes through the two previously unjoined vertices. |
Delete triangles | Used to select the triangles in the main window that you want to delete from the surface. |
The "Pick and Drape Lines on TIN" function is used to pick a line or polyline from the main window and project it into the loaded surface. If the option "Create new points on intersections" is checked, a point will be created at each intersection between a triangle of the surface and the line; otherwise only the line's present vertices will have their elevation changed.
The "Calculate average slope" function is used to calculate the average slope along a selected polyline or within the shape it generates. The function will calculate the average of all triangles that are inside or touching the polygon formed by the closing of the polyline. It's possible to enter the slope of all triangles that are touched; the annotation will appear in the triangle's center.
The "Simplify points of surface" function is used to reduce the number of points included in the surface, by analyzing the surface using a grid. It will divide the surface into a grid whose mesh dimensions are entered in "Grid size". It analyzes each box and if the elevation of all of that box's points does not vary by more than the value in "Elevations tolerance", only one point will be kept. If the difference in elevation is greater, the box will be separated into quarters and the analysis will proceed on each new box. This task will be repeated as many times as given by that section's last value. If the "Use plane" box is checked, instead of verifying the difference in elevation, the distance between each point and the box's average plane will be the one used.
The "Simply triangulation" tool simplifies the point cloud by analyzing its triangulation and discarding triangles that does not show enough variation in slope and elevation with their neighbors. If “Simplify by grid” was also chosen, the triangulation will be done afterward, which will greatly diminish process time. “Slope tolerance” is the minimum variation of a slope between triangles to be considered significant. “Elevation tolerance” is the minimum difference of elevation to be considered significant. Breaklines can also be extracted and simplified with an maximum deviation and variation.