# Thread: regular polyhedra and cameyo´s zplace

1. ## regular polyhedra and cameyo´s zplace

here is a method to do in zbrush, using cameyos zplace, a regular polyhedron, which can be used for example for gems ...

there are 5 regular polyhedra : tetraeder, cube, oktaeder, dodekaeder and ikosaeder. here, polyhedra.zip, you can find those 4 not contained in zbrush as default tool.

i present a method which produces an ikosaeder, a mathematician would certainly not call regular, but for graphic purposes we are save to call it so

(if you like you can produce the same way with the obvious changes, the simplest one seemed to me the oktaeder, then the tetraeder, then dodekaeder and finally the ikosaeder.)

so we are not going to calculate rotation angles but rather eyeball them. for better accuracy, i recommend increasing the canvas size, i used here 1280x960. but the default size works also (though you have to play around a little to find the correct values for zplace.)

1. we need a regular triangle. i did first make one from a plane rotating the borders, but i like michaels (stonecutter) method better as it is easier. here it is : take the cylinder tool, initialise it with x-size=y-size=100, z-size=0, hdivide=3, v-divide=0 and deaktivate the smooth settings sh and sv. this gives more polygons than the plane method, but who cares.

2. we need to rotate the triangle conviniently, and put the objectcenter. we rotate by z-axes 90 degree and then offset in positive y direction so that it looks like in image 1

(again, the y-offset is done by eyeballing, as the preview window is rather small its easier draw the tool for that on your canvas, really big, and activate move, the gyro center is where the object center is, now use deformation slider until the gyro center in on the lower boundry. distance could be calculated, but thats unconvinient as zbrush uses relative scaling system, so we wont bother calculate)

for later use we do a clone of our triangle too.

3. if you work with my canvas size you can take from now on my values, otherwise you need to experiment a little to find the proper ones for you. ok, we rotate the triangle now on x-axes about -11 degree. store that.

4. ready to start cameyos zplace

5. having chosen the triangle put the following values in the array area as in image 2. press p-array and you obtain like image 3.

6. now choose the mm-tool and make polymesh.

7. now delete the markers, choose your new polymesh tool, place it on the canvas (large for accuracy), snapshot, mark, rotate by 180 degree, move one pixel down (so the second marker gets a differnt y coordinate), mark again, should look like image 4. choose mm tool, draw on canvas, check if it looks ok, then make polymesh.

8. remove the markers, choose the clone triangle we made, rotate it by 52 degree on x-axes. for more accuacy you can play around with this value as long as your patience last ok, use the settings from image 2 again, press p-array. you obtain image 5. choose mm-tool, check and make polymesh.

9. remove markers, draw the first polymesh we did on canvas, mark it, put the second on top and mark it, like image 6 (again, just eyeballing rotaion by z-axes and size). choose mm-tool, check, make polymesh.

10. same as 9, with the third and sesond polymesh, you get image 7. this goes a little easier when we rotate the 2 polymeshes with the deform palettte around z axes and put center like in image 8 and 9 (so in 8 the lower edge is horizontal, while in 9 the upper edge clothed to you is horizontal.)

happy making polyhedra

2. Hi Kokoro
A new true gem of the use of Cameyo's Script
That's could interest StoneCutter too
Have happy gemming
Pilou

3. yes i know, since he was the one to make me try ...

4. That is very interesting. With the flattening option under Tool>Modifiers>Deformation>Flatten, you could create a truncated icosahedron, or football (soccer ball) or Bucky ball, or whatever you call it. Unless there is an easier way...

Maybe not...The mesh is not right.

5. Hi Kokoro
Do you know this guy ?
Some images
Have funny surfing anf Zplacing!
Pilou

6. kaz, yes i know, thats also interesting. here the focus howeever was on the regularity, this made the problem.

frenchy, no i never heard of him. but interesting surfing. thanks. - i do come from a different area, so to speak. i just got interested in stonecutters problem on doing icosaeder for his hiv-virus image...because he mentioned the patience needed...

7. Hi Kokoro
Geometry is on everywhere
Pilou

8. Hi kokoro,
very useful info.

cameyo

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