topic Tube in Libraries & objects

Tube

Anonymous — Wed, 06 Jul 2005 18:45:34 GMT

What is the easiest way to make tube ... I'm going nuts trying to figure it out. THis is what i have but i don't understand how everything works.

TUBE 4, 5, 1+2+16+32,

-1", -4", 0,
1", -4", 0,
1", 4", 0,
-1", 4", 0,

0,0,0,0,
0, 0, 5, 0,
3, 0, 5, 0,
3, 4, 5, 0,
3, 4, 0, 0

The edges are not straight they get cut. Any help would be greatly appreciated.

Thanks

Re: Tube

James Murray — Wed, 06 Jul 2005 19:22:12 GMT

TUBE needs 'phantom' points beyond the beginning and end points. The angle between these and the 'real' beginning/end points determines the miters. In other words, the first and last segments are invisible, but they still miter with the 2nd and next-to-last segments.

I assume you want square ends.

In your code, the miters are pointing down to meet the first and last points where you have z=0. But you also need to change the values of X in the first point and Y in the last. So all the Zs are 5, and the first X is in line with the angle from Xsub2 to Xsub3, and the last Y is in line with the angle from Ysub4 to Ysub3.


TUBE 4, 5, 1+2+16+32, 

-1", -4", 0, 
1", -4", 0, 
1", 4", 0, 
-1", 4", 0, 

-1,0,5,0, !-1 is 'behind' 0 from the point of view of 3
0, 0, 5, 0, 
3, 0, 5, 0, 
3, 4, 5, 0, 
3, 5, 5, 0 !5 is 'beyond' 4 from the point of view of 0

One more thing. If it was me, I would make all the Zs 0 and use ADDz to jump up before making the tube. I would rather have more transformations and simpler tube code.

Re: Tube

Anonymous — Wed, 06 Jul 2005 19:33:11 GMT

Wow.....

Thank you very much

Re: Tube

Anonymous — Wed, 06 Jul 2005 23:36:47 GMT

James

TUBE confuses me, too.

If you have moment could you help me with the following:

I want a non-circular tube with, say, 7 points in the 'poly' where I am limiting the maximum Y to be about .3M and Maximum X to be about 1.5M.

The tube is to be formed such that the inner radius is not likely to be less than .6m but could be as much as, say, 20M. The angle subtended by the tube would small, perhaps only 2 degrees in some cases (depending on the radius), because I want these to be elements rotated about the center of the inner radius, so as to form individual components within a larger object.

Of course, the planes of ends of the tube need to be along the radii.

There is no increment in the Z coordinate.

At prseent I have formed the objects using REVOLVE, but I need to add PLANE at the start, and end, of the array of the rotated objects i.e. only two PLANEs.

Re: Tube

David Collins — Thu, 07 Jul 2005 06:15:30 GMT

Or as it's so beautifully explained in the Manual:

"Note: The path comprises two points more than the number of generated sections. The first and the last points determine the position in space of the first and the last surfaces belonging to the TUBE. These points only play a role in determining the normal of the surfaces, they are not actual nodes of the path. The orientation of the surfaces is the same as that of the surfaces that would be generated at the nodes nearest to the two endpoints, if the TUBE were continued in the directions indicated by these.)"

Re: Tube

James Murray — Wed, 13 Jul 2005 15:11:26 GMT

MikeS wrote:
TUBE confuses me, too.

If you have moment could you help me with the following:

Eek. Image/diagram/screenshot maybe? Happy to give it a shot.

Are you talking about imitating TOLER? That is, changing the segment quantity depending on the radius? I figured that out once, I would have to dig it up.