# Joining two lines(3D) with a circular arc fillet

1. Aug 11, 2007

### velanvela

Hi all,
I have two lines in three dimensional form [P1(x1,y1,z1),P2(x2,y2,z2), and P3(x3,y3,z3), P4(x4,y4,z4) ] joined by a fillet, with known radius. i want to know the, start of the fillet(bend), end of the fillet, center of the fillet in a mathematical expression. with the above solution, i can formulate in a C program for further use. Thanks in advance.

regards
velan

2. Aug 11, 2007

### dontdisturbmycircles

Please read or at least glimpse over all the stickies in the sub-forums for which you post for the first time. Problems like these belong in the homework help subforums.

3. Aug 11, 2007

### velanvela

Hi all,
I have two lines in three dimensional form [P1(x1,y1,z1),P2(x2,y2,z2), and P3(x3,y3,z3), P4(x4,y4,z4) ] joined by a fillet, with known radius. i want to know the, start of the fillet(bend), end of the fillet, center of the fillet in a mathematical expression. with the above solution, i can formulate in a C program for further use. Thanks in advance.

regards
velan

4. Aug 11, 2007

### uart

Hi velanvelam, are the two lines assumed to be co-planar (that is, are they known to intersect).

Last edited: Aug 11, 2007
5. Aug 12, 2007

### Dick

If by fillet you mean an arc segment tangent to the two segments, what makes you think such a thing even exists if the two segments aren't coplanar?

6. Aug 13, 2007

### velanvela

No, the two lines are not in the same plane.

regards
velan

7. Aug 13, 2007

### HallsofIvy

Staff Emeritus
Since this is also posted in the homework thread, I am joining the two.

8. Aug 13, 2007

### Dick

The arc itself defines a plane. If the two segments are not coplanar then the arc can't be tangent to both.