Controling DTM contour lines

[propstuff at MJLA]

I'm having a bit of trouble getting contours to display cleanly.

In the attached example the "circular" Pad is at +13200, the "rectangular" pad with the slope applied is also at +13200 and the corner of the 2 Pads are snapped to each other. The blue 'cross' Stakes at +13000 are DTM modifiers controlling the contours, and the black triangles are just indicators.

As you can see; the +13200 (light grey) contour is doing a little Watusi-dance around the meeting of the flat and the sloped +13200 pads.

This sort of little glitch is not unusual and is not normally a problem, but in this case the display of the contours is important.

Any ideas how to force the DTM to display cleanly (aside from using lots and lots of stakes)

Is there such a thing as a "Stake Line" -rather than a point?

N.

[islandmon]

1/cos of slope angle appers to be influencing the Z contour value at this point.

Sometimes it's easiest just to edit the 2d contour curve rather than messing with the

underlying 3d issues.

[gScott]

nicholas

try separating the pads by a small amount,

even as small as 25mm or 1", and update the

DTM.

it usually does the trick...

[Thom]

I agree with islandmon. I have spent several hours trying to get contours to display properly. Gone as far as placing tight 3D loci to try to force the contours to cooperate. This is one of the major weaknesses in the DTM model.

[propstuff at MJLA]

Sometimes it's easiest just to edit the 2d contour curve rather than messing with the

underlying 3d issues.

I don't know how you'd do that. The 2D contours are generated by the 3D model and are not "editable" AFAIK.

Or do you mean convert a copy to polys and edit that?

try separating the pads by a small amount,

even as small as 25mm or 1", and update the

DTM.it usually does the trick...

I tried your suggestion, and it made it worse, then I fiddled around some more; backwards and forwards, and eventually it dispalyed properly.... :-/

Gone as far as placing tight 3D loci to try to force the contours to cooperate.

This is what I've done in the past, but I'd like a better way of doing it.

cheers,

N.

[P Retondo]

Nicholas and Thom, I agree that we need a better way to control the generation of contours. Control points come to mind as a concept. It would be good, also, to come up with a more refined and interactive method for creating proposed contours.

[Charles Chandler]

You can use the Site Modifier object to control specific contours. Here's what I do:

* Click the Site Modifier tool.

* Draw a poly defining where the contour should be.

* Double-click the last point on the contour to complete the creation process. Note that this Site Modifier will be defined by an open poly, not a closed one typical for a "pad".

* In the Object Info palette, set the modifier type to "pad", and set the elevation to that of the contour being defined.

* Update the DTM.

Now you should get exactly what you want.

[propstuff]

Thanks Charles,

I didn't realise a "Pad" could be "open".

That went a long way to controlling them. Some are still refusing to come to heel, but I'm mostly there.

cheers