21st June 2002, 12:16  #1 
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Platonic Solids
try to do an Tetrahedron
but i can only rotate around the Y Axis and why are the green lines behind of the blue ones? 
21st June 2002, 12:22  #2 
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the same prob. with an Octahedron:

21st June 2002, 15:45  #3 
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You're using replace mode, so the next superscope will overwrite the previous one. You can use additive/maximum to get around this, but to do actual depthculling is very difficult unless you shade by depth (z) and use maximum mode.

21st June 2002, 17:11  #4 
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sometimes i hate avs like this
<( LOL ) 
21st June 2002, 18:22  #5 
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Well, that last one looks pretty good.
Stoke me a clipper. I'll be back for Christmas.  Arnold Rimmer Red Dwarf 
21st June 2002, 18:35  #6 
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Circle segments
I think the 3 partitions would look better as circle segments rather than triangles though...

21st June 2002, 22:06  #7 
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i just try it!
here is the work in progess overwiew pac, btw. same prob. (can !only! rotate with x or y Axis) GEEEKS Help määän! (before i try a supermäään logo!) 
21st June 2002, 22:54  #8 
Major Dude

I like all the Radioaktiv presets except for the first and last one...
I can see the limited rotation... Your best bet to make it at least more dynamic  Use getosc/getspec on the OnBeat section. I'll look into the coding some more and see if I can solve the prob... [soon to leave, sirs] 
22nd June 2002, 00:01  #9 
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hmm need a onbeatfunction to move the 3 triangels around the YAxis (10°20° back and forward (vY^)+(^Yv)).
then I don't need to redesign the 3 triangels! can somone explain getosc/getspec variable settings a bit more plz?! 
22nd June 2002, 10:30  #10 
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You seem to have some trouble getting the 3 sideshapes right. Try this in one superscope:
if (i < 0.5) draw circlearc (30°) clockwise at radius 90% if (i > 0.5) draw circlearc (30°) counterclockwise at radius 20% That should get you what you need. On top of that, you can easily rotate this shape by adding a phaseangle to the circlearcs' begin and endpoints Here's the scoop on getosc (same applies to getspec): v = getosc(point,width,channel); point is a value from 0...1 that defines which oscilloscope point you want width is a smoothing parameter. a value of 0 means no smoothing (normal behaviour), a value of 0.1 means that the surrounding values that are in the range of 10% will be blended. For example getosc(0.3,0.1,0) will grab all the values between 0.25 and 0.35 and average them. This is useful if you want a shape to be sound responsive, but not get too distorted by high frequencies (rapid changes). channel sets which soundchannel you need, 0=center, 1=left, 2=right 
22nd June 2002, 19:25  #11 
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TILT!
sorry, need a break! perhaps I will try to fix this later?! 
24th June 2002, 18:39  #12 
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its like potstrike: it becomes warmer

25th June 2002, 20:05  #13 
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 fixed the Octahedron
 make a Cuboctahedron, a Torus + a cell: 
30th June 2002, 06:34  #14 
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All this math is *WHOOSH* above my head
I just started learnind Dynamic Movements 
1st July 2002, 21:35  #15 
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yea, do this and tell me how to use them

3rd July 2002, 19:44  #16 
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Well...As for the rotation, you could just apply the scope(s) to a normal 3D rotation (I explained this in my Primer, but no one seems to be downloading it it's probably at the bottom of the forum by now )
BTW, sorry, but I haven't actually looked at the preset, I don't have WA on this comp (nor do I have access to a comp with WA). I'm just catching up with the forums while I'm away... "guilt is the cause of more disauders than history's most obscene marorders" E. E. Cummings 
9th October 2002, 18:14  #17 
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my last work: (sorry, it is not perfect!)
http://mitglied.lycos.de/llldino/Bilder/NUKE.jpg <<!nuke.ace>> 
9th October 2002, 18:55  #18 
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Your radioactive threefoil sign looks perfect

9th October 2002, 21:09  #19  
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Quote:


9th October 2002, 22:38  #20 
Forum King

WTF? How the hell did I miss this one?
Anyway, I better check out these presets. Xion, .ace is a zip alternative. Last edited by jheriko; 9th October 2002 at 22:56. 
10th October 2002, 16:47  #21 
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>Xion got to => http://www.winace.com/ (i think, winzip also support acefiles)
>jheriko, do you make your icosahedron pic with an ssc? >UnConeD: "Your radioactive threefoil sign looks perfect " Thanks, Yes but i like to cange: 1. the rotation, (x/y/z & reaction on beat) 2. add yellow or green Fog, 3. filled shapes (darkgreen or black). please, give me some tips! >http://cage.rug.ac.be/~hs/polyhedra/6to12anim.gif who will try to do this? >If you have VRML installed, check this: Tetraeder Spirale 
10th October 2002, 18:05  #22 
Forum King

Yup, its a ssc.
The reason I was a bit surprised at seeing this thread is because I released a minipack containing presets centred around the Platonic solids which contains a preset for each of them, 4 of them use filled faces made from scopes and one of them uses wireframe. If you are interested I have also made a rhombic dodecahedron which features in my Pack VI. My next pack will probably feature a couple of other solids, I did make a cuboctahedron but that ones already been done so I'm working on a icosidodecahedron (triacontrahedron with pentagonal and hexagonal faces  like a soccer ball) by using the golden ratio do determine its vertices and a rhombic triacontrahedron by using powers of the golden ratio. Here are links to my the packs I mentioned above: Purely Platonic Jheriko  Pack VI If you really want that animated gif as an AVS preset, I could do probably do it in wireframe, doing it solid would require that the vertices were ordered in a specific way (clockwise or anticlockwise) but it is possible, I may give it a pop if I'm feeling mathematical later on... Yeah your radioactive symbol was very good, if you want to fill it in I can give you some recommendations. To fill the circle the easiest way is probably to make your ssc go from the centre to one of the circle points, then back again, then to the next point on the circle... by using an alternating variable per point. I'd recommend that if you are going to do it, NOT to do it that way since although it is easy to code it will look like poo without a very high number of points, it would be better to make lines that zigzag across the circle by spliting it into two equal curves (vertical semicircle then mirror it with x=x would proably be easiest) and use an alternating variable to make it draw lines from the first point on one curve to the second point on the other back to the third on the first... and so on. You could fill the other shapes by mathematically defining them in a similar way since they are all symetrical, and since they are made of lines and circle arcs it shouldn't be too difficult to figure out. 
10th October 2002, 23:28  #23 
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jheriko
very nice pacs! hope, i will get more time for avs (shool work sucks! ) some nice links: http://www.polyedergarten.de/klintro.htm http://www.georgehart.com/virtualpolyhedra/vp.html http://www.georgehart.com/ http://astronomy.swin.edu.au/~pbourke/ 
10th October 2002, 23:50  #24 
Forum King

I don't suppose you happen to have any links which list polyhedral vertex coordinates, I'm gettig really sick of working them out, some of the larger ones take ages, especially when they have very little symmetry since you have to work out practically every vertex individually.

11th October 2002, 00:34  #25 
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Maybe you could model them in CAD/3DSMAX and export the coordinates as a textfile?

11th October 2002, 01:10  #26 
Forum King

Sounds like a good idea, but would those coords be nice numbers? Probably some hashed up messy skank using square roots every which way...
Then again I could just divide them all by varying powers of phi to make them nicer. Thats mainly so tht the code is easier to type in and nicer to look at otherwise I'd end up with something like: x1=if(equal(q,3),1.078912323,x1); y1=if(equal(q,3),2.414276302,y1); ... which is hassle if you have to type out numbers like that 90 times. 
11th October 2002, 08:19  #27 
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3 decimals should be enough...

11th October 2002, 09:43  #28 
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I guess as a mathematician I have some kind of bizarre desire to see numbers being expressed as accurately as possible... I did a few web searches to find coordinates and I managed to find a few sites with coordinates for the platonic solids and some other shapes defined in terms of numbers like sqrt(2) and phi so I'm going to be lazy and use some of them. Thanks for the tip though.
If any one else is interested: http://www.rwgrayprojects.com/Lynn/C...s/coord01.html This one saved me the trouble of figuring out the rest of the rhombic triacontahedron. It also has a few more coords. 
11th October 2002, 10:23  #29 
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As an engineering student I see math as the tool I need to solve certain problems. If you don't need anymore accuracy, why bother?
At 320 width, one pixel is 0.00625 AVS units wide. So for a 2D scope you don't need any more than 3 decimals in your constants. Given the fact that in 3D scopes, you divide by Z (> 1) most of the time, usually you can settle for 2 decimals. 
12th October 2002, 14:08  #30  
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Quote:
http://users.pandora.be/novokaine/pi/32000.txt Jesus loves you [yes, you] so much, he even died for you so that you will not need to die, but live forever 

13th October 2002, 07:49  #31 
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31,769 signifigant digits. DAMN.
"guilt is the cause of more disauders than history's most obscene marorders" E. E. Cummings 
13th October 2002, 09:55  #32 
Forum King

Pi and e to 100000 decimal places, courtesy of Mathematica. It took about 3 seconds to calculate it. I would have done them to 1000000 but that would have probably taken about half an hour.

13th October 2002, 12:13  #34 
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The only reason that huge amount of significant digits is useful is for statistical analysis for randomness and such. For most practical purposes, 3.1415 is enough precision (whenever I say this to a mathematician, they usually attempt to come up with some excuse why a larger precision would really be better!).

13th October 2002, 13:32  #35 
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Don't usually find myself over here, but my eye was caught by the title.
Has anyone tried any concave polyhedra yet. May I suggest the Great Dodecahedron  it is formed from just 12 intersecting pentagons and looks easy ( but what do I know ). It also breaks the Euler formula that links vertices, edges and faces. Sorry to intrude, please carry on UJ 
13th October 2002, 14:24  #36 
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The only problem is that you need a good way of depthculling each face against the others. This isn't easy in AVS. You could simulate a zbuffer as color value (using maximum blend), but then you'd need to tesselate each face into short line segments to get any sort of accuracy.
Or you could split it up in nonintersecting triangles, guaranteed to be fun :P. 
14th October 2002, 00:26  #37 
Forum King

A relatively simple way to not draw hidden faces is to make sure that the coordinates are entered in a certain order, clockwise or anticlockwise, then to see if from the perspective of the viewport the coordinates are being place clockwise or anticlockwise, if they are in the wrong order then you don't draw the face. The only problem with that method is that it only works 100% for convex objects.
As for pi I can remember being told something like 'if the universe were a perfect sphere and its radius was the distance from us to the furthest known object, then you could calculate it volume to within a cubic meter of accuracy by using pi to 10dp'. I can't remeber the exact number, it could have been 15 or 20dp but it was definately a lot less than 30000. EDIT: The other thing is that if you are doing a calculation where you need to multiply pi several times then the error will increase more and more. 
14th October 2002, 07:56  #38 
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Jher: I guess I should've used a different term. If you look at that great dodecahedron you can see every face intersects practically every other face. Traditional culling isn't going to work here, you need zbufferish techniques to handle that. And getting a smoothly shaded pentagon isn't easy either.
By the way, I haven't actually encountered powers of pi in any formula. I know about pi^2/6 as the limit of some expression, but that's about it. 
14th October 2002, 08:12  #39 
Forum King

Yeah, but you could split it into triangles like you said. I'm sure that the normal back face culling method would work fine then, although i remember reading somewhere that it fails for certain convex objects.
I'll let the powers of pi thing slip though, and just pretend that you didn't say that (any trig function working in degrees/graduations). I'll admit that having pi to any excessively large accuracy serves no practical purpose yet. 
14th October 2002, 09:17  #40 
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Number of parsecs (Smallest possible unit, WITHOUT involving quantum physics) between 2 edges of universe = Digits required.


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