Site model defaults to very large contour interval, crashes

[Pedro P. Palazzo 1]

I am having trouble generating some site models. In some cases the plugin defaults to a minor contour interval that is absolutely too large. If I accept this setting the model renders fine, but if I want to change the minor interval the application hangs. If I render it as a mesh, however, I don't seem to get any problems, but I really need contours in plan. 3D data validation returned no problems with my data.

Edited February 22, 2012 by Pedro P. Palazzo

[Tamsin Slatter 287]

The minor contour interval is the difference in height between one contour and the next. However, the major contour is not the height interval - it is asking you after how many lines you would like to draw a major contour.

For example:

Minor contour interval of 200mm and a Major contour interval of 5 will give a major contour every fifth contour line, so, every metre of level change.

So, the minor contour interval will be higher than the major contour interval. The fields contain different types of data.

Hope that helps!

[Pedro P. Palazzo 1]

Thanks, I rephrased my difficulty?there seems to be no issue with the major interval setting. It is the minor interval that is causing a problem. I am processing some 20 topographic maps with mixed 3D polygons and point data. Some of the models render just fine with a contour interval of 1m (the interval of the 3D polys). Others absolutely want larger intervals and will crash if I reduce that interval. Again, I am always validating the data and VW says it's fine.

[Pedro P. Palazzo 1]

In trying to better frame the issue, it seems that the boundary is at fault here. If I try to create the contours without a bounding polygon it will render fine in every case, but if I use a polygon to set a boundary it will crash with some elevation sources.

[Tamsin Slatter 287]

I'm not sure what you mean by a bounding polygon. You should not need to draw that as Vectorworks will create a boundary for the site model. You then use the Site Modifier tool in boundary mode to limit how much of the site is updated by other modifiers.

[Pedro P. Palazzo 1]

OK, I think I figured it out. So I have these 20-odd square map sectors that are located side by side, each with its boundary and contour lines. I *could* just have extracted all the contour lines to a single layer and made a big 10x10km site model, but I'd rather keep them separate for ease of rendering whenever I won't need the whole thing at a glance. I need the boundaries so that each square model will sit exactly next to the other, without overlap and without blanks in between.

Anyway the problem I was facing had to do with trying to build each site model in isolation from the other. I hadn't realized VW doesn't like a boundary to be flush with the end of the contour lines. As soon as I had the contour lines extend outwards from the site boundary everything started working smoothly. I did that by eventually extracting all the contours to a single layer, and then applying each site boundary over *all* the contour lines. Not sure what I'll do once I reach the edge squares, though......

[CipesDesign 79]

Not sure this will help, but I think I would approach the problem like this: build one big site model, then use viewports, appropriately cropped, to show any smaller area(s). Also, you might try referencing the Site Model into each larger scale portion of the entire project. That would allow for separate files for the smaller portions (lots?) of the project... Whatever you do just be triple sure to save backups of every step, just in case things get wacky. That way you can at least get back to somewhere reasonable.