Hi, I'm new to povray. I'm designing a 3V geodesic dome and for checking I got
all the angles and coordinates right, I rendered my design in povray. Now I
want to include an image of the three different strut lengths with their so
called "compound cuts". This turned out more difficult then I expected. What is
the best way to create an image like
http://northernhomestead.com/wp-content/uploads/Geodome6.jpg.

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"Janne" <arc### [at] mecom> wrote:
Now I
> want to include an image of the three different strut lengths with their so
> called "compound cuts". This turned out more difficult then I expected.

I'll bet   ;)
Last I recall, there's lots of nested cosines or something.

I'd start by searching woodworking or geodesic forums, or even those "sacred
geometry" sites to see if anyone's got some good charts or spreadsheets or PDF's
or something.
I could swear that there's something like this for POV-Ray - maybe check out
Friederich Lohmueller's site forst, and then see if was done by someone else
after that.
Some stuff might even be right in the Insert Menu.

> What is
> the best way to create an image like
> http://northernhomestead.com/wp-content/uploads/Geodome6.jpg.

Can't see it:


Access denied
What happened?
The owner of this website (northernhomestead.com) does not allow hotlinking to
that resource (/wp-content/uploads/Geodome6.jpg).

security by CloudFlare"

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Am 2016-05-12 18:24, also sprach Bald Eagle:

> Can't see it:
>

> Access denied

WORKSFORME


-- 
dik

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On 12/05/16 23:24, Bald Eagle wrote:
> "Janne" <arc### [at] mecom> wrote:
> 
>> What is
>> the best way to create an image like
>> http://northernhomestead.com/wp-content/uploads/Geodome6.jpg.
> 
> Can't see it:
> 

> Access denied
> What happened?
> The owner of this website (northernhomestead.com) does not allow hotlinking to
> that resource (/wp-content/uploads/Geodome6.jpg).

> security by CloudFlare"
> 

No problems on this side of the pond.
Attached is a scaled copy of the original illustration ..under Fair Use
provisions of various copyright acts.

John
-- 
Protect the Earth
It was not given to you by your parents
You hold it in trust for your children

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Attachments:
Download 'geodome6.jpg' (78 KB)

Preview of image 'geodome6.jpg'

> Hi, I'm new to povray. I'm designing a 3V geodesic dome and for checking I got
> all the angles and coordinates right, I rendered my design in povray. Now I
> want to include an image of the three different strut lengths with their so
> called "compound cuts". This turned out more difficult then I expected. What is
> the best way to create an image like
> http://northernhomestead.com/wp-content/uploads/Geodome6.jpg.
>
>
>

Assuming that +X is to the right, +Y is up and +Z is forward. That's the 
standard left handed coordinate system that POV-Ray use.

Start with a box.
Use a difference with two smaller boxes at each end.
For the part that you show, the two box need to be rotates first by 

The best way, in my view, would be to start with the main box going 
toward +X and centered around the X axis.
Next, have a smaller box that you rotate as follow:
rotate<-4.71, 55/2, 0>
Make two copies, the second copy will scalled as follow to make it into 
a mirror image:
scale<1,1, -1>
Finaly, translate those toward the end of the main box.

Try to keep the smaller cutter boxes as small as possible.



Alain

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Alain <kua### [at] videotronca> wrote:

> Start with a box.
.....
> Finaly, translate those toward the end of the main box.
>
> Try to keep the smaller cutter boxes as small as possible.

Yep, that'll give the graphical or geometric solution.
Always easier to do that if you just want to get the result and display it.

Or start with the dome itself and cut toward the center, bisecting the angles,
and that should show the angles of the joint.

http://jansson.us/jcompound.html
http://www.practicalmachinist.com/vb/metrology/compound-angles-167024/
http://www.pdxtex.com/canoe/compound.htm
http://www.waterfront-woods.com/festool/Compound_Miter.pdf
http://www.blocklayer.com/compoundmitereng.aspx

and on and on and on....

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"Bald Eagle" <cre### [at] netscapenet> wrote:
> "Janne" <arc### [at] mecom> wrote:
> Now I
> > want to include an image of the three different strut lengths with their so
> > called "compound cuts". This turned out more difficult then I expected.
>
> I'll bet   ;)
> Last I recall, there's lots of nested cosines or something.
>
> I'd start by searching woodworking or geodesic forums, or even those "sacred
> geometry" sites to see if anyone's got some good charts or spreadsheets or PDF's
> or something.
> I could swear that there's something like this for POV-Ray - maybe check out
> Friederich Lohmueller's site forst, and then see if was done by someone else
> after that.
> Some stuff might even be right in the Insert Menu.
>
> > What is
> > the best way to create an image like
> > http://northernhomestead.com/wp-content/uploads/Geodome6.jpg.
>
> Can't see it:
>

> Access denied
> What happened?
> The owner of this website (northernhomestead.com) does not allow hotlinking to
> that resource (/wp-content/uploads/Geodome6.jpg).

> security by CloudFlare"

Hi Bald Eagle,
Sorry fot the not working link. It's just an image of a compound cut. I've done
all the calculations for the dome but showing an image of a compound cut seemed
more difficult then doing the whole dome.

Post a reply to this message

Alain <kua### [at] videotronca> wrote:

> > Hi, I'm new to povray. I'm designing a 3V geodesic dome and for checking I got
> > all the angles and coordinates right, I rendered my design in povray. Now I
> > want to include an image of the three different strut lengths with their so
> > called "compound cuts". This turned out more difficult then I expected. What is
> > the best way to create an image like
> > http://northernhomestead.com/wp-content/uploads/Geodome6.jpg.
> >
> >
> >
>
> Assuming that +X is to the right, +Y is up and +Z is forward. That's the
> standard left handed coordinate system that POV-Ray use.
>
> Start with a box.
> Use a difference with two smaller boxes at each end.
> For the part that you show, the two box need to be rotates first by

> The best way, in my view, would be to start with the main box going
> toward +X and centered around the X axis.
> Next, have a smaller box that you rotate as follow:
> rotate<-4.71, 55/2, 0>
> Make two copies, the second copy will scalled as follow to make it into
> a mirror image:
> scale<1,1, -1>
> Finaly, translate those toward the end of the main box.
>
> Try to keep the smaller cutter boxes as small as possible.
>
>
>
> Alain


Hi Alain, Thank you for your reply. I'll give It a try after the weekend. Doing
the whole dome was much more straightforward then showing an image of a compound
cut though.

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On 5/13/2016 7:24 AM, Janne wrote:
> Sorry fot the not working link. It's just an image of a compound cut. I've done
> all the calculations for the dome but showing an image of a compound cut seemed
> more difficult then doing the whole dome.

You could have used a PovRay generated image. ;-)

And welcome. :-)

-- 

Regards
     Stephen

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"Janne" <arc### [at] mecom> wrote:

> Hi Bald Eagle,
> Sorry fot the not working link. It's just an image of a compound cut.

nbd - the issue seems to be on my end or somewhere in between me and the url.

> I've done
> all the calculations for the dome but showing an image of a compound cut seemed
> more difficult then doing the whole dome.

If I understand it all well enough, the calculations for laying out the dome
itself are different than laying out the compound angles of the joints as you
want.

I'd say that the POV-Ray / graphical / geometric solution will be the fastest
and easiest, though will leave you without knowing what angles to cut IRL on a
saw, if that's what is eventually intended.

I'd say you could _start_ there, while you work on the mathematical solution, so
you can get the scene file working and ready for a side-by-side comparison or a
full 3D overlay.

If you're going to use the difference {} approach, then I'd suggest that you
define your cutter boxes as separate objects    "Cutter_1 = box { .... }, etc.
That way you can do any rotations and translations on it and THEN do
difference {
Board
Cutter_1
}
to get your "cut", but the advantage is that you can then add into your SDL
something like object {Cutter_1 pigment {rgbt <1,0,0,0.7>}}
to see exactly where you're actually placing the cutter for the difference.

It helps when you're trying to figure out what went wrong, as so often happens,
but the cutters are essentially invisible.

Feel free to post WIPs so we can help you puzzle this out, and as Stephen said:
"Welcome!"   :)

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