On Tue, 10 Jun 2008 13:44:56 +0200, "Thomas de Groot"
<t.d### [at] internlDOTnet> wrote:

>About your second comment: It might depend on the type of space involved. 
>The present setting would be rather claustrophobic, depending on the size 
>relationship with human beings. 

And the local gravity ;)

>I am not too concerned about this now, 

I didn't think so :)

-- 

Regards
     Stephen

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"Bill Pragnell" <bil### [at] hotmailcom> schreef in bericht 
news:web.484e748d7b589d73731f01d10@news.povray.org...
> Not to blow my own trumpet too blatantly, but I think this looks much 
> better!
> Although that's partly because you've also got the lichen texturing just 
> right
> - it looks really realistic. How do the render times compare?

I am very satisfied with your macros, Bill. It does an excellent job where 
my previous experiments with isosurfaces grinded to a halt because of 
excessive render time. This scene parses and renders in about 20 minutes, of 
which about 12 or 13 is parsing. But of course, the mesh objects are already 
done. The parsing of the column segment takes about 3 to 4 minutes with a 
resolution of 300.

>
> "Thomas de Groot" <t.d### [at] internlDOTnet> wrote:
>> took some experimenting until the shape came out right,
>
> I find this to be the case also.

Size and position of the inner shape are crucial in relation to displacement 
depth. And the resolution of course :-)

>
>> Another difficulty is the base of the column which consists of a flat CSG 
>> of
>> torus and cylinder. I have not (yet) been able to approximate that 
>> correctly
>> with the macro.
>
> Don't forget, you can relocate the object to be eroded before calling the 
> macro.
> If you move it upwards slightly it may improve things (the underside won't 
> look
> nice, but obviously that's not visible!). Another thing to try is the 
> inner
> shape - a wide rounded cylinder could well work better than the default
> squashed sphere.
>
Yes, I am aware of the relocation posibillities and have used those 
extensively (min_extent and max_extent are pretty helpful here) and have 
used also a cylinder as inner shape which works better for these column 
segments.
My problem for the time being is with the column base which consists of a 
complex CSG of toruses and cylinders. I probably have to think about a 
complex inner shape too, especially as the object is very flat.

Thomas

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"Thomas de Groot" <t.d### [at] internlDOTnet> wrote:
> I am very satisfied with your macros, Bill. It does an excellent job where
> my previous experiments with isosurfaces grinded to a halt because of
> excessive render time. This scene parses and renders in about 20 minutes, of
> which about 12 or 13 is parsing. But of course, the mesh objects are already
> done. The parsing of the column segment takes about 3 to 4 minutes with a
> resolution of 300.

I'm very glad to hear it. Render speed was my primary motivation.

> Yes, I am aware of the relocation posibillities and have used those
> extensively (min_extent and max_extent are pretty helpful here) and have
> used also a cylinder as inner shape which works better for these column
> segments.

Good, I was just checking!

> My problem for the time being is with the column base which consists of a
> complex CSG of toruses and cylinders. I probably have to think about a
> complex inner shape too, especially as the object is very flat.

I can't quite make out the cross-section in your image. You could try merging a
vertically-stretched torus with a flat cylinder, if that makes sense. I guess
you've probably thought of all this already... good luck with it, and I'd be
interested in your eventual solution!

Bill

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Bill Pragnell napsal(a):
> "Thomas de Groot" <t.d### [at] internlDOTnet> wrote:
>> I am very satisfied with your macros, Bill. It does an excellent job where
>> my previous experiments with isosurfaces grinded to a halt because of
>> excessive render time. This scene parses and renders in about 20 minutes, of
>> which about 12 or 13 is parsing. But of course, the mesh objects are already
>> done. The parsing of the column segment takes about 3 to 4 minutes with a
>> resolution of 300.
> 
> I'm very glad to hear it. Render speed was my primary motivation.
> 
>> Yes, I am aware of the relocation posibillities and have used those
>> extensively (min_extent and max_extent are pretty helpful here) and have
>> used also a cylinder as inner shape which works better for these column
>> segments.
> 
> Good, I was just checking!
> 
>> My problem for the time being is with the column base which consists of a
>> complex CSG of toruses and cylinders. I probably have to think about a
>> complex inner shape too, especially as the object is very flat.
> 
> I can't quite make out the cross-section in your image. You could try merging a
> vertically-stretched torus with a flat cylinder, if that makes sense. I guess
> you've probably thought of all this already... good luck with it, and I'd be
> interested in your eventual solution!
> 
> Bill
> 
> 
You may try a vertically squashed superellipsoid (rounded cylinder)

-- 
the ultimate time-killer:
+a0.0 +am2 +r9

Johnny D

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"Bill Pragnell" <bil### [at] hotmailcom> schreef in bericht 
news:web.484ea28a7b589d73731f01d10@news.povray.org...
>
> I can't quite make out the cross-section in your image. You could try 
> merging a
> vertically-stretched torus with a flat cylinder, if that makes sense. I 
> guess
> you've probably thought of all this already... good luck with it, and I'd 
> be
> interested in your eventual solution!
>

I am sorry for the very bad composition of this image, but it is just a test 
to show what I am talking about. The red object is the original column base, 
the green object is obtained with a cylinder as inner shape. Not good yet, 
as I more or less expected. I tried with a scaled down copy as inner shape, 
but that was not satisfying either. Next, I want to try with an adapted copy 
of the original.

If you want to experiment, I attached the original inc file to this message.

Thomas

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Attachments:
Download 'BP_meshdemo.jpg' (29 KB) Download 'IonianColumnBase.inc.txt' (2 KB)

Preview of image 'BP_meshdemo.jpg'

"Thomas de Groot" <t.d### [at] internlDOTnet> wrote:
> If you want to experiment, I attached the original inc file to this message.

It is not surprising that you're having trouble; there are too many gaps in the
base object. Look at the cross-section in the image below!

You need to close these gaps, especially the thin gap across the centre and the
concave underside. Unless the square peg-hole has some special purpose I'd plug
this too. And don't forget to make sure it's a merge, not a union, or the
internal surfaces get hit first!

A default flattened sphere as inner object should work OK once you've filled the
gaps.

Hope this helps!

Bill

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Attachments:
Download 'coltest.jpg' (30 KB)

Preview of image 'coltest.jpg'

"Bill Pragnell" <bil### [at] hotmailcom> schreef in bericht 
news:web.484fad347b589d73731f01d10@news.povray.org...
>
> It is not surprising that you're having trouble; there are too many gaps 
> in the
> base object. Look at the cross-section in the image below!

Of course! You warned exactly against this, and I never thought to check the 
internal aspect of the object! Thank you, Bill, I totally overlooked this 
:-)
A clear case not only of RTFM, but also of : Apply TFM!

>
> You need to close these gaps, especially the thin gap across the centre 
> and the
> concave underside. Unless the square peg-hole has some special purpose I'd 
> plug
> this too. And don't forget to make sure it's a merge, not a union, or the
> internal surfaces get hit first!
>
> A default flattened sphere as inner object should work OK once you've 
> filled the
> gaps.
>

Yes, I am going to do that...

Thomas

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"Bill Pragnell" <bil### [at] hotmailcom> schreef in bericht 
news:web.484fad347b589d73731f01d10@news.povray.org...
>
> It is not surprising that you're having trouble; there are too many gaps 
> in the
> base object.

I closed the gaps, and this is the result (with rounded cylinder as inner 
shape). The square hole (used for transport of stone blocks and/or anchoring 
of column segments) does not really interfere, so I left it in place.

Thomas

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Attachments:
Download 'BP_meshdemo.jpg' (33 KB)

Preview of image 'BP_meshdemo.jpg'

"Thomas de Groot" <t.d### [at] internlDOTnet> wrote:
> I closed the gaps, and this is the result (with rounded cylinder as inner
> shape). The square hole (used for transport of stone blocks and/or anchoring
> of column segments) does not really interfere, so I left it in place.

Much better :-)

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"Thomas de Groot" <t.d### [at] internlDOTnet> wrote:
> I have also put my teeth into Bill Pragnell's Mesh Approximator macros,
> revisiting the ruined place I had been working on earlier.
>

I'm just now becoming aware of Bill's macro(s).  (Where have I been??) What an
extremely useful tool.  Nice work, Thomas! Can't wait to see more.

Ken W.

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