#DXFin Contours?
3 messages in this thread
3D mavens: This is a sub-optimal situation, but it is the one I am in: Trying
to import '3D' DXF from Acad. In general, we get lots of survey drawings of
sites that have contours, and if you are lucky, they will even have valid Z
elevations. (If not, you can usually give the correct elev with not too much
trouble.) I do not have any nifty tools to 'drape' or otherwise fit a 3D mesh
of some sort to the contours. I have been trying several variations to import
SOMETHING usable. Followed recommendations in 3Ds manuals, changed all
contours to layer 0, no text or any other junk, just '3D' plines (2D plines
with elev), DXFed each set of contours out separately. A couple will load into
3DS, but most say 'No 3D entities'. Can't merge either. I guess I'm trying to
do this the hard way not using/generating some kind of mesh, but these type of
contour files are what we get all the time, not some pretty mesh. The point in
this case also is to take as little time, as few translation and manipulations
as possible to turn around a number of small renderings quickly. Oh, have just
tried this on a small portion of a 2Meg file, so I am sure file sizes are not a
problem (files are probably 5-10k each,10 files). Advice appreciated. eof
Charles
3dsurf.pxp from Schreiber Instruments works great converting 2 and 3d plines
from acad into a 3ds mesh. 1 800 252 1024
JB
If you want to do something that's free, try this (I use it all the time).
Assuming you have a polyline for each contour line, and each polyline is up in
space at the proper elevation in AutoCAD space (i.e. 0', 5', 10', etc.). Run
the 3D Surfaces command, use the Rulesurf command, and pick two adjacent 3D
polylines. This will create a 3D mesh object connecting the two polylines. The
Surftab 1 and Surftab 2 variables control the resolution of the resulting mesh.
I use a value of 2 for the up/down the slope value, and anything else for the
cross-slope value. Set this value as high as you want to ensure a more accurate
mesh file. Pick each pair of polylines in the same order as you move up or down
the slope. This technique breaks down a little if you have really curvy
contours, in which case the faces tend to overlap around corners.
If you do this on a given layer such as Surface01, then turn off the other
layers and DXF this layer out.
If you have any questions, drop me a line…
Regards, Gary