masking errors using CUTPOLYA and REVOLVE

[Anonymous]

I am trying to punch holes using CUTPOLYA in a dome shape created with the REVOLVE command. I cannot mask the sides of the cut holes. I cut the same holes in a flat prism and the sides masked properly, so the problem must be in the revolve command. No matter which masking value I use I cannot see the sides of the hole. Any help would be appreciated.

Steve

[Anonymous]

Steve,
We need to know which version of AC you are using because
CUTPOLYA has changed from AC 6.5 & AC 7 to AC 8 and again
from AC 8 to AC 9.
We also need to know when you say "mask the sides of the cut holes"
do you mean the surfaces of the sides
or do you mean the edges of the sides of the holes ?
Thank you,
Peter Devlin

[Anonymous]

Peter,

I am using 8.1 r2. The half/dome shape created by REVOLVE has a mask of 63. So the edges of the dome are masked( it appears as though the dome is solid.) However when I cut a hole elsewhere in the dome the dome appears hollow (You can see the inside surface of the dome through the hole). I have placed a simple prism in the path of the CUTPOLYA and the holes in the prism are masked correctly ( the prism appears solid). I also checked to make sure that the points comprising the CUTPOLYA are outside of the REVOLVE shape. The points for the CUTPOLY are stored in an array. All points in CUTPOLYA have a mask of 15. Here is a link to the image http://www.domus-usa.com/mask_problem.jpg Here is link to the code http://www.domus-usa.com/mask_problem.txt

Thanks in advance

Steve[/img]

[Anonymous]

Peter,

I have discovered that if I REVOLVE NSP/3, 360,63, GET(NSP) instead of 180 degrees the holes mask correctly. Is this a bug?

[Anonymous]

Steve,
Please try these three experiments.

Pull a section through the dome shape
to see if it shows as solid in S/E window.

Draw a marquee in plan that cuts through the dome and view in 3D
to see if it is solid.

Use the dome as operator on another object as target
in an SEO to see if it behaves as a solid.

The reason I suggest this is that the problem my not be with
CUTPOLYA but with the dome.
I have found sometimes in AC 8.1 that some elements that
should be solid sometimes are not.
Thank you,
Peter Devlin

[Anonymous]

Peter,

I solved the problem by revolving 360 and then chopping it in half to 180. I also checked with the Marquee and it looks ok. Thanks for all your help!

Steve

[Anonymous]

Steve,
It appears that you have discovered that the dome is not solid
as I suspected.
No I do not think it is a bug.
Check the description of REVOLVE in the manual.
Note what it says about mask values.
Thank you,
Peter Devlin

[Anonymous]

Revolve, tube, sweep, and the other polyline commands are not solid and don't cut nicely. A while back I made a bizarre shape for a Architectural Uni student and I had all sorts of problems. He was never happy with it because it didn't have a think wall. It would be nice if there was a command to make them solid and if the solid operations worked on them within the GDL script. Or have they fixed this in 9?

Julia

[Anonymous]

Julia,
Your statement "Revolve, tube, sweep, and
the other polyline commands are not solid" puzzles me.
In AC 8.1 and AC 9.0 I have found the "shapes generated from
polylines", namely the commands
EXTRUDE, PYRAMID, REVOLVE, TUBE, and MASS are solid,
while RULED, SWEEP, and COONS are surface only.

When I say "solid" I mean that any element that passes the
following two tests is solid.
One, when cut with a section line and viewed in the S/E window
the section contour pen is the library parts own section contour pen
or the one assigned in the sections pen settings.
Two, except for "degenerate" objects, the element as operator
does SEO with other objects as target.

The commands I list as "solid" all pass the two tests.
There is one caveat and that is the parameters of some commands
if set a certain way cause the command to become a surface only.

What am I missing ?
Peter Devlin

[Anonymous]

Peter wrote:
Julia,
The commands I list as "solid" all pass the two tests.
There is one caveat and that is the parameters of some commands
if set a certain way cause the command to become a surface only.

What am I missing ?
Peter Devlin

It is probably me missing something, the objects I have done (that I have actually cared enough to notice) tend to be surfaces. I know I had to find a work around for cutting holes in a bench top to put a vanity basin in that was made as a revolve.