Hi,

We use POV-Ray images to generate animations from a structural
impact modeling tool that we develop (Objexx-SISAME-3D).

I am having some trouble with cylinder and sphere bounding boxes
becoming visible when viewed through a semi-transparent box. The
problem appears when I have two copies of some of the shapes that
are closely overlapped but not coincident.  Increasing 
max_trace_level did not help.

An example of this can be seen in the file I posted to
povray.text.scene-files  (news:40ca3772@news.povray.org).  If you
look at the right rear wheel you can see the wheel and hub sphere
bounding boxes.

Any suggestions would be greatly appreciated!

--

Stuart
http://www.objexx.com

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> I am having some trouble with cylinder and sphere bounding boxes
> becoming visible when viewed through a semi-transparent box. The
> problem appears when I have two copies of some of the shapes that
> are closely overlapped but not coincident.  Increasing 
> max_trace_level did not help.
Didn't look at your code, but if you got intersecting (semi-) 
transparent objects, try to merge them using

merge {
	object { MyObject1 }
	object { MyObject2 }
}

this removes all inner surfaces. Be aware that it can increase render 
time, though.

HTH,
Florian

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Thanks!  Using merge did improve things but it really hurts rendering
time, as you said.  A reliable and fast way to get rid of the problem 
is to scale the second copy by .999 and thus eliminate any coincident
surfaces -- I had missed that there were still some of these.

Stuart

"Florian Brucker" <tor### [at] torfboldcom> wrote in message
news:40cc6fbf$1@news.povray.org...
| > I am having some trouble with cylinder and sphere bounding boxes
| > becoming visible when viewed through a semi-transparent box. The
| > problem appears when I have two copies of some of the shapes that
| > are closely overlapped but not coincident.  Increasing 
| > max_trace_level did not help.
| Didn't look at your code, but if you got intersecting (semi-) 
| transparent objects, try to merge them using
| 
| merge {
| object { MyObject1 }
| object { MyObject2 }
| }
| 
| this removes all inner surfaces. Be aware that it can increase render 
| time, though.
| 
| HTH,
| Florian

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