COMPUTER AIDED ARCHITECTURAL DESIGN

Workshop 5 Notes, Week of October 3, 2011

 DIGITAL TERRAIN MODELING PART I

Note: This workshop focused on a a few introductory digital terrain modeling methods. The primary method of more immediate practical value is captured under item #1 below as applied to Carr's Hill. We will advanced to other methods later on  involving external "tin" and "lat" files  the offer more complete analysis options that you might undertake in studio. 

 
            

           

1.  Terrain Modeling  (expeditious method)

       
        dgn file of Carr’s Hill
  1. Open SiteCarrsHill.dgn from the classes folder.
  2. Rotate to view 3D survey data – typical of GIS data received from municipality
  3. Create and make active a new layer titled "simpleTIN".
  4. In a few weeks time we will explore other possibilies with layers to capture an advancedTin and latticed mesh terrain model.
  5. Turn on predefined contour layers named " INDEX" and" INTERMED", and turn off all other layers except for the active layer simpleTIN.


    create levels


    make simpleTIN the active level
  6. Select "Mesh from Contour Tool" from pull out toolbox from icon in lower left-hand side of Surfaces palette.


  7. Select the tool and then hold down continuously the left mouse button to draw an invisible box around the contour lines on the screen. Move the mouse off the contour lines, and hit the left mouse button  to accept the contour lines and generate a triangulated mesh.

             

2. Terrain from Image File: New CAD File (Due to a temporary configuration issue, it is necessary to use the older version of Microstation V8i for this exercise).

  1. The Image underlay file topo2.jpg that has been placed in in classes is a scanned in image of a site plan with topological lines. –
  2. Note the scale of topo2.jpg  is 1”=300’ and the actual dimensions of the scanned in image are 7.5 x 12 inches in paper size
  3. Close the image
  4. Inside Microstation, draw rectangle at an appropriate size for attaching  topographic image above,  using the Addudraw popup calculator in the coordinate text boxes for "X" and "Y". After entering a lower left-hand data point, then for the "X" coordinate enter "=" and then "300 * 7.5", and for the "Y"coordinate enter "=" and then "300 * 12.0".


  5. Fit View
  6. Use the File Menu/Raster Manager dialog box, and interactively load the file topo2.jpg and use the "Place Interactively" feature so that it is scaled to the rectangle created in step 4.

  7. Use the Utilities>KeyIn dialog box, to enter "MDL Load Civtools" (tool available for download from School of Architecture website)

  8. Within the Civtools dialog box:
    1. [P] tools – parameters – set major/minor interval and colors/layers

    2. Choose first tool – place contours - establish elevation level for each contour line and trace over the scanned in image using the curve tool option, and setting "planar" check box to on.

    3. Note: you need to explicitly enter in new elevation values into the Place Contour dialog box for each contour line, such as the elevation 580' above.

  9. Set current elevation – 600 – and draw
    Keep going up the mountain.
  10. Once the contours have been created, you may use either Surface tool "Mesh from Contours" tool to build a terrain file.  (Here is a version of the above file with contour lines (blue) re-loaded and normalized from the external TIN file.