AUTO AREAL CALCULATION(POLYGONE DIVIDED INTO TRANGLES )

[Praveen p]

I WANT AUTO AREA CALCULATION WITH TABLE LIKE DRAWING ATTACHED.

AM BEGINNER.

area calculation.dwg

[BIGAL]

There are free triangle lisp out there look for TriangV0.5.09.lsp here at Cadtutor its by YMG as 1st step. It may have been updated.

 

The second to do the 90 offs if the shapes are always convex then a centroid approach to each point get crossing lines, may work if you get a "L" or "U" shape then that method will fall down.

[Praveen p]

already i wrote this program by using triangulation lisp but 

some unwanted trriangles also forming in this type(check attached PDF).

i want  triangles within the vetices.

code will run both convex or concave polygon

area calculation.pdf

[BIGAL]

Having worked with TINS for years the triangulation can often give the wrong desired result a square is a simple example of wanting triangles other way, thats why some software has a a "FLIP" face that reorients the 2 triangles, for you simplest would be delete and manually create 3dface.

 

There  is also delete a face if you have internal curve made up of lots of points then you will get a lot of tiny triangles that need deleting that is why there is often a delete outside boundary function. Look for Lee-mac convex hull and Extrim or Cookiecutter2.lsp to trim outside.

 

The 90 lines would be a separate function ran after happy with triangles.