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2023-09-29
08:29 AM
- last edited on
2023-10-04
01:50 PM
by
Laszlo Nagy
Is it possible to create an elliptical hemisphere like the image with GDL commands?
If so, what command should I use?
2023-09-29 08:37 AM
You could use a SPHERE and cut it in half.
Or better still there is an ELLIPS command that is half a sphere where you can control the height independent of the radius.
But in either case to elongate one axis, you will need to use the MUL command.
Barry.
2023-09-29 09:21 AM - edited 2023-09-29 09:31 AM
For the shape presented, ELLIPS would not work as that would create tangents along the cut rather than a Spherical Cap.
For the presented shape 3 variables would need to be defined. R1 you circles radius, R2 to distort it using MUL and H, used in conjunction with R1 to calculate R3, your spheres radius.
R3 = ( R1^2 + H^2 ) / 2H
With R3 in hand, you can then subtract H to set your CUTPLANE. OR better, offset your sphere into your cutplane.
Ling.
ps. Curious what would require such a shape... something that requires an object to be scripted...
AC22-23 AUS 7000 | Help Those Help You - Add a Signature |
Self-taught, bend it till it breaks | Creating a Thread |
Win11 | i9 10850K | 64GB | RX6600 | Win10 | R5 2600 | 16GB | GTX1660 |
2023-09-29 12:48 PM - edited 2023-09-29 12:52 PM
If you don't want to use GDL an alternative would be to use the Shell tool.
Basically you would draw a half ellipse and rotate it around the long axis by 180 degrees.
2023-09-29 01:40 PM
Or just use the 'ellipsoid' primitive shape object in the default library.
It even has a cutting plan for half an ellipsoid.
Barry.
2023-09-29 02:37 PM
🤔 I can't believe the primitives are localised but I'm not seeing that split option in the UKI library...
2023-10-01 12:33 PM
I only have 22 open at the moment.
This is what I see (AUS library).
Unless it has changed in later versions?
Barry.
2023-10-01 12:45 PM
I just checked 26 and no there is no cutting plane option or hollow shell.
Why do they take options away?
There is a semi-sphere object, but you can not stretch it.
That ellipsoid I have in 22 may even be from an older library still.
It has no license restrictions or author information I can see, so I have attached it here.
Barry.
2023-10-02 03:49 AM
Yep, Ellipsoid 22 does not have the option...
AC22-23 AUS 7000 | Help Those Help You - Add a Signature |
Self-taught, bend it till it breaks | Creating a Thread |
Win11 | i9 10850K | 64GB | RX6600 | Win10 | R5 2600 | 16GB | GTX1660 |
2023-10-02 04:30 AM
I checked out the origin of that object I posted and it looks like it is from version 10.
It seems newer amended objects are not always better (did someone say 'cabinets' ? )
Barry.