First use of Mesh, unable to add enough ridges

[Anonymous]

Hello

I downloaded the demo of ArchiTerra and I was annoyed to find it didn't work on the student version of ArchiCAD 8.1! I hadn't realised that add-ons do not run on student licences. It was in searching for reasons why it didn't work I came across this forum and saw people suggesting meshes.

I am trying to create a large (4km by 5km with a range of 60m to 220m above sea level) terrain model, showing a group of gorges/dykes that I hope to populate with some foliage and occasional buildings and a bridge.

I have a map created in polylines of 5m contours. Using the mesh and magic wand tool I have produced a very impressive (to me) 3D model of most of this area, but now the magic wand tool does not seem to create ridges. I wonder whether there is a limit set to the number of nodes/ridges I can use, or whether I need to make the whole model in a series of separate meshes.

Also does anyone have any good ideas how to add roadways on the model, and how to add foliage (varying green lumpy bits) without using trees from the standard library that would be far too large in memory for rendering?

If anyone can help I would much appreciate it!

(2nd year architecture student who uses ArchiCAD as per the office I work in, as opposed to university who only like Vectorworks, Sketchup and Cinema4D!)

[Anonymous]

Your Lordship,

I've done a bit of this and will pass along what I know.

1) Keep the mesh simple. Don't add too many nodes. I've found that magic-wanding imported DWG contours results in twenty times more nodes than are necessary for a convincing model. It's best to trace with a spline, line or polyline (economically), then magic-wand with the mesh tool.

2) You can add individual spot grades in addition to the contours to create the ridges you want, but of course it takes more time than magic-wanding contours.

3) Once you've created a model of the existing terrain, make a copy of it (paste to a different story or layer or drag a copy up, give it a layer, then drag it back in position). The one mesh is new, the other existing.

4) Modify the contours of the new terrain to reflect new roads, building sites, etc., then make road surfaces with new meshes and give them an appropriate road-like material (and layer). Simple roads and surfaces can also be made with roofs and slabs, but if they have any complexity at all it's best to use the mesh tool.

5) The best flora I've used for rendering is the "tree bitmap" library part in the ArchiCAD library. It shows up in plan as a plant symbol and in section/elevation and 3D window as a vertical plane. Put them on the mesh with the gravity on and orient them all in the same direction. Then, in the 3D window, use the find and select option from the edit menu, adjust it to select only library parts named "tree bitmap" (unless you want to group them all), select all all of them, open the dialog and rotate them all so that they face the camera. Render the image, then rotate them again when you're at a different camera angle. The results are pretty good, although I wish there were more species to choose from. There may be a similar library (bitmap) part available out there somewhere which would give you more variety. I've never been able to get plant models to look good. They have more polygons than the terrain itself (makes everything very slow) and look really phony in renderings.

6) Be patient. It takes time.

My long-ago experience with ArchiTerra was not good. It was very troublesome.

Now you know as much as I do. Good luck!

[Thomas Holm]

Use this tip
http://www.graphisoft.com/support/archicad/archiguide/surveyordrawings.html
to simplify your model. Very useful. The mesh will normally be quite alright, even with a small percentage of the original number of points.