I'm sorry to ask this but I suspect this is one of my big problems with 
making scenes look realistic...

When I define an object (let's use a round stand), I would do something 
like:

A vertical cylinder to represent the top of the stand
a torus to round the edges of the stand
a vertical cylinder to represent the side of the stend.

I'm doing all this to give the shape soft/rounded edges

(hope this makes sense) but although I can do it in simple cases, to do it 
for (say) a box would require 3 boxes, 12 cylinders and 8 spheres.

Is this the only way? Is this how it was done for individual blocks in the 
P.b-i "Yet Another CGSphere Entry" post ? or is there some way to "erode" ?

Any help greatly appreciated

Thanks in advance
S

Post a reply to this message

Ok, so I meant "newbie" :P


"Simon" <povray@*NOSPAM*SOWare.co.uk> wrote in message 
news:46739cc9$1@news.povray.org...
> I'm sorry to ask this but I suspect this is one of my big problems with 
> making scenes look realistic...
>
> When I define an object (let's use a round stand), I would do something 
> like:
>
> A vertical cylinder to represent the top of the stand
> a torus to round the edges of the stand
> a vertical cylinder to represent the side of the stend.
>
> I'm doing all this to give the shape soft/rounded edges
>
> (hope this makes sense) but although I can do it in simple cases, to do it 
> for (say) a box would require 3 boxes, 12 cylinders and 8 spheres.
>
> Is this the only way? Is this how it was done for individual blocks in the 
> P.b-i "Yet Another CGSphere Entry" post ? or is there some way to "erode" 
> ?
>
> Any help greatly appreciated
>
> Thanks in advance
> S
>

Post a reply to this message

Wasn't it Simon who wrote:
>I'm sorry to ask this but I suspect this is one of my big problems with 
>making scenes look realistic...
>
>When I define an object (let's use a round stand), I would do something 
>like:
>
>A vertical cylinder to represent the top of the stand
>a torus to round the edges of the stand
>a vertical cylinder to represent the side of the stend.
>
>I'm doing all this to give the shape soft/rounded edges
>
>(hope this makes sense) but although I can do it in simple cases, to do it 
>for (say) a box would require 3 boxes, 12 cylinders and 8 spheres.
>
>Is this the only way? Is this how it was done for individual blocks in the 
>P.b-i "Yet Another CGSphere Entry" post ? or is there some way to "erode" ?

If you take a look at the shapes.inc documentation you'll find some
predefined macros that create rounded boxes, cylinders and cones. They
do it the same way that you would do it: a rounded cylinder is two
cylinders and two toruses, a rounded box is 3 boxes, 12 cylinders and 8
spheres.

It's not the only way. You could do something with isosurfaces, but it
would probably run quite a bit slower. You can also create things that
look something like rounded boxes and cylinders with the superellipsoid
object, but again it tends to be slower than using unions of simple
objects.

-- 
Mike Williams
Gentleman of Leisure

Post a reply to this message

Have you had a look at this site - there  are lots of pre-defined shapes and
things and I found the downloads very useful.
http://www.f-lohmueller.de/pov_tut/objects/obj_000e.htm
Zog
"Simon" <povray@*NOSPAM*SOWare.co.uk> wrote in message
news:46739cc9$1@news.povray.org...
> I'm sorry to ask this but I suspect this is one of my big problems with
> making scenes look realistic...
>
> When I define an object (let's use a round stand), I would do something
> like:
>
> A vertical cylinder to represent the top of the stand
> a torus to round the edges of the stand
> a vertical cylinder to represent the side of the stend.
>
> I'm doing all this to give the shape soft/rounded edges
>
> (hope this makes sense) but although I can do it in simple cases, to do it
> for (say) a box would require 3 boxes, 12 cylinders and 8 spheres.
>
> Is this the only way? Is this how it was done for individual blocks in the
> P.b-i "Yet Another CGSphere Entry" post ? or is there some way to "erode"
?
>
> Any help greatly appreciated
>
> Thanks in advance
> S
>
>

Post a reply to this message

"Simon" <povray@*NOSPAM*SOWare.co.uk> wrote:
> Is this the only way? Is this how it was done for individual blocks in the
> P.b-i "Yet Another CGSphere Entry" post ? or is there some way to "erode" ?

The blocks in that image were created using none of the methods mentioned
above. I wrote a macro to create "eroded" bricks as mesh2 objects -
basically a 'rounded' cuboid made purely of triangles which can then be
perturbed using pigment functions not dissimilar to those used in
isosurfaces.

I just need to tidy this macro up and then I'll post it. :-)

Bill

Post a reply to this message

web.46740c8bb9b3baa3fd8b0db80@news.povray.org...
> The blocks in that image were created using none of the methods mentioned
> above. I wrote a macro to create "eroded" bricks as mesh2 objects -
> basically a 'rounded' cuboid made purely of triangles which can then be
> perturbed using pigment functions not dissimilar to those used in
> isosurfaces.

Clever!

>
> I just need to tidy this macro up and then I'll post it. :-)

Yumm :-p--

Marc

Post a reply to this message

Thank you all for your replies - it's helped me a great deal.

Bill: I'd like to see that macro whenever you've got it to a state you're 
happy with - I'm curious how you've done the optimisations.

I need to learn about isosurfaces. I've done degree level engineering so 
have a firm math foundation but never really touched onthem beyond "this is 
the eqn for a sphere"... so if anyone could point me in the right direction 
for some reading material, I'd be greateful!

Again, thank you all

-Simon
"Simon" <povray@*NOSPAM*SOWare.co.uk> wrote in message 
news:46739cc9$1@news.povray.org...
> I'm sorry to ask this but I suspect this is one of my big problems with 
> making scenes look realistic...
>
> When I define an object (let's use a round stand), I would do something 
> like:
>
> A vertical cylinder to represent the top of the stand
> a torus to round the edges of the stand
> a vertical cylinder to represent the side of the stend.
>
> I'm doing all this to give the shape soft/rounded edges
>
> (hope this makes sense) but although I can do it in simple cases, to do it 
> for (say) a box would require 3 boxes, 12 cylinders and 8 spheres.
>
> Is this the only way? Is this how it was done for individual blocks in the 
> P.b-i "Yet Another CGSphere Entry" post ? or is there some way to "erode" 
> ?
>
> Any help greatly appreciated
>
> Thanks in advance
> S
>

Post a reply to this message

"Simon" <povray@*NOSPAM*SOWare.co.uk> wrote:
> Bill: I'd like to see that macro whenever you've got it to a state you're
> happy with - I'm curious how you've done the optimisations.
On its way. Not sure what optimisations you mean, but it's on its way!

> I need to learn about isosurfaces. I've done degree level engineering so
> have a firm math foundation but never really touched onthem beyond "this is
> the eqn for a sphere"... so if anyone could point me in the right direction
> for some reading material, I'd be greateful!
Well, if Mike's not going to blow his own trumpet I'll certainly blow it for
him. Whenever I get confused about isosurfaces his tutorial is my first port
of call:

http://www.econym.demon.co.uk/isotut/

Bill

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"Simon" <povray@*NOSPAM*SOWare.co.uk> wrote:
> Ok, so I meant "newbie" :P
Lol, that shed a whole new light on "newbie". :-D

Post a reply to this message

"Simon" <povray@*NOSPAM*SOWare.co.uk> wrote in message 
news:46739cf4@news.povray.org...
> Ok, so I meant "newbie" :P

  Heh, welcome aboard the PoV-Ray train, Simon. You've already bought your 
first-class ticket, so enjoy the ride!


       ~Steve~

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