View Full Version : Circular Hole in a Cylinder ?

03-05-2003, 12:37 PM
Here is a doozie!

How would I create a circular hole in a circular platform?

The end result would resemble a coin with hole in the centre.

RichDiesal has a tutorial on creating a circular Hole in the Floor/Ceiling
(Curves 201: Lesson 3) at


Which is a good start, but this would give me a square with a round hole in the center.

What would be the best way of fixing up the area around the square to turn it into a circle?

Any input and ideas are appreciated.



03-05-2003, 01:00 PM
Ah, yes...yet another mapper seeks to enter the Cult of the Patch... BWAHAHAHA!!!

Okay, first, make an outer cylinder, the one you will put a "hole" in, matrix facing out. Don't cap it. Make a smaller cylinder, the size of the hole, inside the larger one, matrix facing in. THat was easy. Now, make a brush that's tall and skinny. To make things easier, make it as wide as the difference in radii of the cylinders (so it fits between them), and a little taller than half the outer cylinder's diamter. Click Curves > Simple patch mesh, and then select a 3 x 3 patch. Your brush will turn into a "flat curve," with 3 vertices in each dimension. Now you hit V to enter vertex editing mode, and you'll see the vertices appear on your mesh. Drag them around until the patch curves along between the two cylinders.

There's no way to explain how to do that in words, pictures are much better. You will probably find my patch mesh reference sheet (http://wso.williams.edu/~jshoer/patches.htm) useful. Look under "3x3 Patches," and what you're interested in is the "Quarter-Arc." Make four of those and rotate them into position. Alternatively, you could make two "Half-Arcs" or one "Donut," but those are much trickier to manipulate.

03-05-2003, 01:16 PM
Originally posted by wedge2211
Ah, yes...yet another mapper seeks to enter the Cult of the Patch... BWAHAHAHA!!!

lol, wedge2211 you are a riot!

Thanks for the help and the link to your site.

Cult of the Patch... tee hee hee

Oh, and by the way, just to let other people know, some patches can be a good way to keep down the complexity and fps of a map. For example, if you play the bespin multiplayer map in devmap mode, and you turn on the showtriangles, you will notice that the some of the stairs are not brushes but made up of patches.

To see the triangles the game engine renders (for those who don't know how)

Shift ~ (Brings up the console)
sv_pure 0 (Run in Pure Server Mode)
devmap ffa_bespin (Run the MP Bespin Map)
developer 1 (Turn Developer Mode on)
r_showtris 1 (Turn On the Triangles)

r_showtris 0 (Turn Off the Triangles)

Enter the Matrix... :)

Have Fun.


Leslie Judge
03-05-2003, 02:56 PM
So developer 1 is the key. :) Good to know.