export 3ds/autocad created terrain from bryce?

[erik]

hi
I have a contour map in Autocad 2000. I created the 3d shape from it in Viz4. But if I import as OBJ into Bryce to create a realistic texture and to reduce the polygon count (it also has buildings on it I do not want to poly reduce) I cannot export the terrain from Bryce.

How do I get the Bryce texture outside of Bryce and how can I effectively reduce the polycount and smooth the terrain?
The finished product I wish to use in a 3d realtime rendering engine.
regards
Erik

[CADTutor]

Welcome to the forum!

Lot of questions. I usually use 3DS format to move terrain objects from MAX/VIZ to Bryce. Then smooth the object in Bryce and apply materials etc.

Although smoothing an imported object in Bryce is easy, I'm not aware of any function that allows you to reduce the polygon count. The simplest way to do this might be to lose every other contour on the original AutoCAD drawing before moving to Studio. The number of polygons is determined by the number of polyline vertices in the contour drawing since Studio uses these vertices to triangulate the model. By taking out every other contour you are reducing the number of vertices and therefore the number of triangles.

I am not aware that there is any way to export the Bryce materials to other aplications and have them work in the same way although it is possible to export an image map from a native Bryce terrain object (not an imported terrain object).

[erik]

just a few hours after the topic I found that yes .3ds format is far better than .obj
There is no explicit way of exporting a procedural texture from Bryce but there is an online tutorial about taking a photo of a mapped texture as a crude workaround.
I used polycruncher on the terrain and it was very effective.

Bryce is excellent for creating viewpoint .mtx/mts terrain for online/adobe atmosphere worlds. But this format is invalid for imported mesh (both oj and 3ds). At least with 3ds you can import and re save the mesh. However the terrain editor option disappears.

My other possibility is to save the original autocad file via a gis type program and find a way of converting the 3d terrain to a height field then importing that heightfield as picture to Bryce, which will hopefully and accurately recreate the terrain but in native Bryce format. This would solve all my problems (apart from Bryce texture export!)
I have ArcView somewhere-this may work.

One other question: Is there an easy way of creating rivers via bryce or 3ds max or Autocad on a sloping site? I have seen excellent tutorials on river valleys in bryce using heightfield editing but they all involve bryce created terrain and are not for slopes (ie the river is horizontal). This is so unsuitable for real world visualisations!

[CADTutor]

Yes, there's no way to convert a mesh object into a Bryce native terrain object - if only! Using a height field image is the only way.

As far as rivers go, I think the best option might be to use a second terrain object for the water - this object would intersect the valley bottom so that only the "river" water is visible and the rest of the object is hidden underneath the actual terrain surface.

In fact, there are lots of interesting effects to be had by combining intersecting terrain objects.