GMS study notes-2

Tin-based Surface Model

Use XYZ coordinate data to generate an irregular triangle mesh. The elevation or other tin-based data can be displayed through the contour.

Tin is used to create a nude model and a 3D finite element grid.

1. Import vertex data

A. Switch to the TIN Model

B. Open the file tutfiles \ tins \ Verts. GPR

2. Gridded

Click triangulate under build Tin

3. Create an Contour

Click Display option to open ipvs and Tin
Boundary option. Close triangle edges and vertices to see the contour.

You can also use the light source to display the top surface: Turn off ipvs and tin boundary in the display attribute to open the triangle faces. Switch to the oblique view, click lighting options under display, and change ambient light to 0.7 to see the effect.

4. Edit Tin

Click the show Option Button to open vertices and contours, click option on the right side of contours, set the interval to 20, click OK, and return.

A. Drag the vertex

① Click the select vertices icon in the toolbar.

Switch to the plan view (X, Y view, and change the X and Y coordinates)

Click a vertex to change the position. The boundary cannot be dragged or dragged.

In the oblique view, you can drag a vertex to change the position of its zcoordinate axis.

② You can also click a vertex and directly change the specific coordinate value in the above coordinate display box. Press ENTER or tab to confirm.

B. Lock the vertex

After selecting the vertex, click the lock/unlock vertices command under modify tin.

C. Add Vertex

Switch to the plan view and select create vertex in the toolbar.

Click the position to be added in the image.

D. Delete

Click Delete in the menu bar after selecting the vertex. By default, after a vertex is deleted, the mesh associated with the vertex will also be deleted. However, you can set the Option Switch to enable automatic mesh re-creation after a vertex is deleted.

Click vertex options under modify tin to open the retriangulate after deleting option.

5. Smooth Tin

When there are few vertices, the generated contour line may be obvious, and the generated contour line can be smoothed by means of an encrypted mesh.

A. Copy the vertex

Click tin under build tin-> 2D scatter points, click OK, and select "no" when asking whether to delete existing tin ".

B. subdivided Tin

Click uniformly subdivide tin under modify tin. In the displayed window, increasing the number of factors will encrypt the current grid.

C. interpolation elevation

The contour line does not change after the encrypted mesh. Follow these steps to smooth the contour line:

Switch to the 2D Scatter Point model,

Select interpolation | interpolate-> active tin. In the pop-up dialog box, you can select the interpolation method. Click OK to see the smooth contour after interpolation.