3d survey

[MaryBea]

I'm trying to draw up a survey taken in 3d of 4 points at different heights (forming a rough square in plan view). I have the height of each point and the distances between each point - 4 measurements around the edge (from point to point) and 2 measurements across the diagonals - all taken in 3d. Please could you explain how I can do this in Vectorworks. (Landmark 2008 on Mac 10.5.6). With many thanks.

Bea

[islandmon]

You can import the survey coordinates and let Landmark do the work via DTM.

Or you can simply layout the plan shape and then program the vertices of a 3dPoly or set 3d loci and connect the points. There's also a survey BoundaryLineTool which accepts your inputs via a Grid Mathod.

[Pat Stanford]

I think you may be able to do it by drawing a 4 sided polygon and applying distance constraints to each side.

Then draw two lines (not the diagonals) and use coincident constraints to make them the diagonals.

select and edit the diagonals to be the proper lengths and the angles of the polygon should adjust to match.

Now put a 3D locus at each of the four corner and and set the proper z-heights.

Finally, select the four 3D loci and Create Site Model.

[Chad McNeely]

These don't sound like survey coordinates, more like along-the-surface measurements?

If so, you have some math (or geometry) to do. It sounds like you have the heights and hypoteneuse of several triangles, in a sense.

pythagorean: a^2 + b^2 = c^2, where a & b are your height and horizontal distances, and c is the sloping measurement. So given a & c, b=(c^2-b^2)^.5

trig: find the slope (angle above to horizontal) between points,

= sin^-1((delta z)(measured distance)),

then the horizontal length is cos(angle found) x (measured distance)

or just draw it out with that handy drafting and geometry producing program that we all love so well...

[MaryBea]

That's it! You're right, it wasn't a survey - I didn't know the terminology ... But now I know about the triangles I see what I have to do. Thanks so much for your help everyone.

Bea