Celestia Forums

I need a disk model with a central hole in order to create an Alderson Disk for Celestia - The perfect compliment to my Dyson Sphere model and the ringworld somebody else made (As you can see I have a thing for megastructures)

I have looked all over the internet for a cd-rom model that I could modify, but to no avail.

Is there a way to punch a hole in the middle of a disk using anim8or? Or am I stuck?

I had a bit of experience with anim8or, and it sounds like you could make a thin rectangle and make an open lathe over the y-axis. Sorry if it doesn't work, but like I said, I only had a bit of experience.

Rectangle? I'd much prefer the hole to be circular.

Whenever I try to lathe a hole in the middle of a disk with a cylinder it give me some stupid error message about a path (?)

Doh! Silly me! I managed to work it out.

Can you simply use a png file (to texture a square for example) and define the zone you need with transparency??

Bye

NoXion wrote:Doh! Silly me! I managed to work it out.

An easy way using Anim8or is to;

1. To make the "main ring", Build a Primative N-gon, say with 30+ sides to make a smooth circle.

2. Drag the mouse to form the circle to the required diameter.

3. To make the centre "cut-out", Build another Primative N-gon with the same number of sides.

4. Drag the mouse to form the inner circle to your required diameter.

5. Select both circles then go into the Build menu and select Join Spilnes.

6. Click on either circle (it will highlight both) and go back to the Build menu, and select Extrude.

7. Choose your required Extrude Parameters for length, and number of segments.
Make sure you have checked the Cap boxes, Start and End.
Make sure the Don't Tesselate Caps box is unchecked.
Then extrude along the z-axis.

After this, you should have a disk with a hole in it.

cheers,
TERRIER

TERRIER wrote:

NoXion wrote:Doh! Silly me! I managed to work it out.

An easy way using Anim8or is to;

1. To make the "main ring", Build a Primative N-gon, say with 30+ sides to make a smooth circle.

2. Drag the mouse to form the circle to the required diameter.

3. To make the centre "cut-out", Build another Primative N-gon with the same number of sides.

4. Drag the mouse to form the inner circle to your required diameter.

5. Select both circles then go into the Build menu and select Join Spilnes.

6. Click on either circle (it will highlight both) and go back to the Build menu, and select Extrude.

7. Choose your required Extrude Parameters for length, and number of segments.
Make sure you have checked the Cap boxes, Start and End.
Make sure the Don't Tesselate Caps box is unchecked.
Then extrude along the z-axis.

After this, you should have a disk with a hole in it.

cheers,
TERRIER

Thank you very much!

Applying the textures was a bit of a puzzle at first, but I used polar coordinates in photoshop and got satisfactory results:

http://img281.echo.cx/img281/7823/disk10vv.jpg

I hope you agree.

NoXion wrote:Thank you very much!

No problem !

NoXion wrote:Applying the textures was a bit of a puzzle at first, but I used polar coordinates in photoshop and got satisfactory results:

http://img281.echo.cx/img281/7823/disk10vv.jpg

I hope you agree.

I've got to admit that textures are not really my forte.
But yours looks very effective.

One thing you might need to check on your disk, is the surface normals to the "central core". Using my method to make it may well have them facing the wrong way, so they may need to be flipped.

regards,
TERRIER