Search found 78 matches

by guy
Sun Aug 07, 2011 7:09 pm
Forum: Polyhedron Models
Topic: Wall Thickness
Replies: 10
Views: 25912

I presume that question's for Guy? I only make models from paper. Just wanted to answer the part of the question I could :) No, I don't post images of real models (except the odd icosahedron in a museum that I think may have been made by H.T. Flather of Coxeter, Du Val, Flather and Petrie fame). An...
by guy
Thu Jul 28, 2011 8:30 pm
Forum: Polyhedron Models
Topic: Wall Thickness
Replies: 10
Views: 25912

Well, the wood will be thinnest in the corners and thickest at the centre of each piece. Assuming you want at least 1/2" everywhere, you need to: Take the difference between the inradius (radius of the sphere tangent to the faces at their centres) and the out- or exradius (of the sphere tanget to th...
by guy
Wed Jun 08, 2011 8:30 pm
Forum: Stella Feature Requests
Topic: Eliminate lighting effects
Replies: 3
Views: 10734

Stella uses OpenGL (the Open Graphics Library) for rendering. AFAIK this is just like the real world in that it needs a light source or everything looks black. The 3D rotation, perspective and stuff is also handled by OpenGL, so decoupling the colour from the rest of the software might be a problem....
by guy
Mon Jun 06, 2011 5:17 pm
Forum: Stella Feature Requests
Topic: Eliminate lighting effects
Replies: 3
Views: 10734

I'm guessing that with no light source, things would get pretty black. I'm also guessing that any polychromatic light source will have consequences for one form of colour-blindness or another. How about an option for a monochromatic light source to match the raw pixels - choice of red, green or blue.
by guy
Sat Jun 12, 2010 8:00 pm
Forum: Stella Forum
Topic: Stella image in New York Review of Books
Replies: 8
Views: 15446

You must be feeling eight miles high (though I prefer the 20 minute live version on the untitled album).
by guy
Wed Jun 09, 2010 3:42 pm
Forum: Stella Forum
Topic: Stella image in New York Review of Books
Replies: 8
Views: 15446

You have your X, Y and Z axes. How do you go beyond these? Mathematically it is really easy, you just add a W axis at right angles to all the others. When you project a 3-D object onto the X-Y plane (say a computer screen), you just forget the Z dimension. Similarly, to project a 4-D object onto th...
by guy
Tue May 18, 2010 8:53 pm
Forum: Stella Forum
Topic: Stella image in New York Review of Books
Replies: 8
Views: 15446

Around a century ago, when extra dimensions first became popularised, people investigated these issues. There is some evidence that Picasso used time and cubism as analogues of the fourth dimension - he was certainly fascinated by it. One painting has a succession of figures as if caught in multiple...
by guy
Sun Apr 25, 2010 9:23 pm
Forum: Polyhedron Models
Topic: Double Tabs.
Replies: 6
Views: 23082

Sounds like the paper is too thin and/or the glue too watery. Depending on the ink, different glues have different effects on the lines. I use a thick art paper or even thin card, and a non-water-based quick-drying glue such as Bostik. But I have to be careful with laser printers, because Bostik dis...
by guy
Sun Apr 25, 2010 8:46 am
Forum: Polyhedron Models
Topic: Cricut paper cutting machine
Replies: 2
Views: 14077

Rob, doesn't Stella offer svg vector output for nets and perspectives? These can be displayed directly in any modern web browser, or printed off, and crucially at any scale without loss of detail. They are even cross-platform. Sorry I can't check my own copy, I no longer run Windows and am not yet c...
by guy
Sat Feb 06, 2010 10:21 pm
Forum: Polyhedra
Topic: Tintin-R
Replies: 1
Views: 9450

Lovely! It reminds me of the rocket in the Tintin story, "Destination Moon".
by guy
Mon Jan 25, 2010 7:21 pm
Forum: General
Topic: MazeRunner
Replies: 7
Views: 23870

robertw wrote:Not sure how saleable another maze program would be though!
Well, how saleable was yet another minesweeper program?
by guy
Mon Jan 11, 2010 3:36 pm
Forum: Polyhedron Models
Topic: Geometric Christmas Ornaments
Replies: 4
Views: 20344

Yes, there are many such polyhedra, known as deltahedra. See for example the Wikipedia
Deltahedron article.
by guy
Sun Jan 10, 2010 1:36 pm
Forum: Polyhedra
Topic: Miller's Monster
Replies: 8
Views: 22537

According to Wenninger, there are 30 pairs of squares. They are diametral or "hemi" faces, so there is no parallel pair. To colour each pair differently would need 30 colours. That makes 6+10+30=46 colours in all. Ouch! Wenninger describes a simpler colour scheme. He uses a simplified set of 5 colou...
by guy
Sun Jan 10, 2010 12:50 pm
Forum: Polyhedron Models
Topic: Geometric Christmas Ornaments
Replies: 4
Views: 20344

Hi, those are beautiful. I wish you all success. What about offering other shapes, such as the stella octangula, rhombic dodecahedron and maybe even small stellated dodecahedron? I have a large-ish model of a small stellated dodecahedron made of shiny golden card that I bring out every Christmas: ju...
by guy
Sun Jan 10, 2010 12:41 pm
Forum: Polyhedra
Topic: Do you ever make polyhedra for other people?
Replies: 7
Views: 22463

I once gave away a great stellated dodecahedron - once I pointed out the pentagonal star faces, my neighbour was fascinated by it.