AutoCAD Land Desktop

New Member
Posts: 2
Registered: ‎03-02-2011
Message 1 of 3 (479 Views)

Terrain Surfaces

479 Views, 2 Replies
10-31-2011 10:22 AM

I need to analyze 2 surfaces for obstructions.  I have a rectangular surface (1,000' x 15,000') that is a 3d polyline with an elevation of 1,500' on one end and 2,250' on the other end.  Then I have a dwg that contains topspot elevation points of buildings, trees, etc.  I need to find which points penetrate the rectangular surface.  I was told there is a very quick way to do this using 3d modeling tools but I haven't had any luck with it.  Anyone have any ideas of a quick way to do this.  I have over 2,500 topspot points to check.

Valued Contributor
Posts: 56
Registered: ‎11-07-2005
Message 2 of 3 (452 Views)

Re: Terrain Surfaces

11-16-2011 06:43 AM in reply to: Kingro

1. build both surfaces and check them for errors (0 elevations, etc...).

2. go to the terrain pull-down and select "select current stratum"  set your plane surface as surface 1 and your topspot surface as surface 2.

3. in "site definition" define your site to include the entirety of both surfaces.

4. now using the just created stratum and site, do a calculate total site volume in the GRID volume calculator.

5. finally, also under grid volumes, generate grid volume ticks. (you will have to do a bit of experimentation to get the grid density set to a manageable level. start with larger numbers and work down to the density you want... maybe a value of 10 tick and label interval at 20 scale to start).

6. lastly, open your layer manager and assign two different colors to the cut ticks & labels, and the fill ticks & labels. for example if you make the cut layers cyan and the fill layers red, all the red areas on your grid is a topspot penetrating your plane surface...


New Member
Posts: 2
Registered: ‎03-02-2011
Message 3 of 3 (450 Views)

Re: Terrain Surfaces

11-16-2011 06:48 AM in reply to: slant

Thanks, I will give that a try.

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