Attached Link: http://www.employees.org/%7Eredneck/graphics/torus_tutorial.htm

The first step is to work out the dimensions. Personally, I have developed a scaling system to ensure that everything I model is at the correct size, and it is based on the size of an average human (in my case, 1 Bryce Unit (BU) = 10cm so that a human is 17.5BU tall; this would be too small a scale for what you are doing, but you still need to settle on to a single, fixed conversion). I eyeballed the sample you posted and played around moving some objects around before I finally worked out the dimensions and got to work.

1. Since the tower is a stretched pyramid shape, you will need a long pyramid object which will be your intersect object. Inside the intersect pyramid (slightly smaller in dimensions) is a negative pyramid. These are shown in rose glass material (later changed to the tower material).

All the rest of the objects are positive.

1. Add two horizontal plates. The lower one will be turned on its Z axis to become a diagonal brace; the upper one will stay as it is as a horizontal brace. Make them different families (colors) so you can easily select one or the other. Multi-replicate them 12 times, moving up on the Y axis.

2. The time-consuming part is to go in by hand and rotate all the diagonal braces on their Z axis. You have to do this by hand because each rotation is different owing to the shape of the pyramid. Every time you rotate a plate, dupe it and then open the attributes menu and reverse the Z rotation (ie, change -34.00 to 34.00).

3. Once you have done all the front and back diagonals, select them all (using the family select), dupe them, group them, then rotate the group 90 degrees on the Y axis. Voila, all your diagonals are done.

4. For the corners, you just need to make a thin panel that extends the length of the tower. Rotate it 45 degrees on its Y axis. Dupe it and change the Y rotation to -45 degrees.

5. Select everything, UNGROUP to make sure you don't have any unnecessary groups, then group them all to get this tower.

You can do the same thing with the crane derricks, except they will be even easier since they aren't pyramid shaped (all the diagonals are the same angle, etc).

In this image, the top elements represent the intersect as well as a slightly smaller negative object. In the center you see all the posts and rails. When you group all these, and change the material, you get the posts and rails seen at bottom.

This technique is extremely versatile. For example, all your rails for a given deck level can be defined by only two objects, no matter how complex the external contours are of the deck.

In this image, I show a simple stairway on the right. On the left, in rose glass, are the intersects for the railing posts. The second from the left shows in green glass the posts and rails, which would be positive. Group the positives and the intersects (and change the materials) and you get the post and rails seen in the third from left. This is much easier to do than making individual posts and rails.

One solution for those millions of railing posts: Instead of making posts and rails, create, say, a thin vertical box representing the railings (one on each side of a stairwell). Make this positive. Then create two thin boxes and make them parallel to the angle of the stairs. Make these intersect and group them with the vertical boxes. Now you have the railings. You can then use multi-replicate to make thin vertical boxes going across the stairs, which when made intersect will look like posts. This will reduce your object count by at least half.

I've made a lot of progress in my own experiments and also discussing ideas with other folks. Unfortunately, I am in Belgium right now and won't be able to start playing again until later this week when I get home. Should have some good stuff then. Thanks for your help. Mitch

Thanks Februrus! I had a look at that site, but also went sniffing around elsewhere. I downloaded the Rhino eval and had a hull (not a very good one) banged out in less than half an hour. Details at: http://www.employees.org/~redneck/graphics/journal_02.htm Thanks for all your help. I'm moving forward now... Mitch

Thanks. I'll try those other tools. I've been hearing from other people I should probably do my modeling with other tools. But if this can be done in Bryce, I'd love to understand how. As you can see from my Web site, I have been using the terrain editor to build the dirigible hull one rib at a time. I'm not happy with this because I don't have a lot of control over the bitmap I'm using (how to paint a nice gradated range of tones representing the curve of the hull?) and in any case this method, while it looks cool, results in a dirigible comprised of at least 72 objects, which is too many just for the hull. Makes scene files unwieldy. A symmetrical matrix won't help me until I can figure out how to produce a greyscale bitmap to describe the hull. If you know how to make some very nice dirigibles in Bryce, I'd love to hear more. Thanks, Mitch http://www.employees.org/~redneck/graphics/journal_01.htm