Hello, everyone.

I'm having a bit of a problem I was hoping you could help me with.

I am attempting to model a room with some windows.  I started by
defining the room as a basic object, hollow mind you, and then subtract
boxes from the object through using the difference function.

I've tried speicifying the boxes as hollow, only the boxes as hollow,
only the room as hollow, and everything not hollow.

Instead, all I get are some black boxes exactly where the difference
should be.

Here's the code:

merge {
  difference {
    cylinder {
      <0, 0, 0>
      <0, 200, 0>
      100
      hollow on
      pigment {
        Grey
      }
      finish {
        ambient 0.5
      }
    }

    box {
      <-110, 70, -4>
      <-90, 80, -2>
      hollow on
    }

    box {
      <-110, 70, 4>
      <-90, 80, 2>
      hollow on
    }
  }
}

Thanks in advance for the help.

Post a reply to this message

Chad Kruger wrote:
> 
> Hello, everyone.
> 
> I'm having a bit of a problem I was hoping you could help me with.
> 
> I am attempting to model a room with some windows.  I started by
> defining the room as a basic object, hollow mind you, and then subtract
> boxes from the object through using the difference function.
> 
> I've tried speicifying the boxes as hollow, only the boxes as hollow,
> only the room as hollow, and everything not hollow.

A common mistake. The "hollow" keyword DOES NOT make an object hollow.
It is there purely for the purposes of the media feature (You will use
"hollow" when you need to use an object as a container for media.)

See:
http://www.students.tut.fi/~warp/povVFAQ/languageVFAQ.html#hollowobjects

 What you need to do is make a box the size you want your room,
difference a slightly smaller box (to define the thickness of
the walls) from the inside of that, and then use your "windows"
boxes to make the window openings.

Again See:
http://www.students.tut.fi/~warp/povVFAQ/languageVFAQ.html#hollowobjects

-- 
Ken Tyler - 1400+ POV-Ray, Graphics, 3D Rendering, and Raytracing Links:
http://home.pacbell.net/tylereng/index.html http://www.povray.org/links/

Post a reply to this message

Ken <tyl### [at] pacbellnet> wrote:
: A common mistake. The "hollow" keyword DOES NOT make an object hollow.
: It is there purely for the purposes of the media feature

  And fog :)

  That is why I have strongly fighted for a change to this keyword.
Something like media_container, container, allow_media, etc would be fine.

-- 
main(i,_){for(_?--i,main(i+2,"FhhQHFIJD|FQTITFN]zRFHhhTBFHhhTBFysdB"[i]
):5;i&&_>1;printf("%s",_-70?_&1?"[]":" ":(_=0,"\n")),_/=2);} /*- Warp -*/

Post a reply to this message

If the boxes used to make the window openings do not have pigments or
textures, the inside of the opening would be black (or the color of the
background?).
Brendan Ryan

>  What you need to do is make a box the size you want your room,
> difference a slightly smaller box (to define the thickness of
> the walls) from the inside of that, and then use your "windows"
> boxes to make the window openings.

Post a reply to this message

"Andrea Ryan" <ary### [at] global2000net> wrote in message
news:394D65BE.6E997F9E@global2000.net...
| If the boxes used to make the window openings do not have pigments or
| textures, the inside of the opening would be black (or the color of the
| background?).

The typical thing to do would be to add the room texture at the end of the
CSG, unless the outside walls are to be different than inside.  If everything
is to be different textures then of course a unique texture would go into each
part of the CSG constituents.  'union' the window parts together and put a
texture for them at the end of that union statement, then that would go after
the room box 'difference' but within that statement and then the rooms texture
at the end of that differencing statement.  The window textures will be
retained.  Outer wall and inner wall can have their own textures too but then
you can skip the final texturing statement if so, unless you intend to
difference anything more away from the room object.
Anyhow, it's all in how the textures are applied, previously or afterward.

| >  What you need to do is make a box the size you want your room,
| > difference a slightly smaller box (to define the thickness of
| > the walls) from the inside of that, and then use your "windows"
| > boxes to make the window openings.

Post a reply to this message

Andrea Ryan <ary### [at] global2000net> wrote:
: If the boxes used to make the window openings do not have pigments or
: textures, the inside of the opening would be black (or the color of the
: background?).

  This statement can be a bit misleading.
  If you have this:

difference
{ object { Room }
  object { WindowHole }
  texture { WallTexture }
}

it might seem that the WindowHole object does not have a texture (there is
no texture block inside that object block, is there?).
  However, it has a texture applied to it: The WallTexture.

  The problem only arises in this case:

difference
{ object { Room texture { WallTexture } }
  object { WindowHole }
}

but here it's more clear that only the Room object has a texture. And I think
povray issues a warning anyways.

-- 
main(i,_){for(_?--i,main(i+2,"FhhQHFIJD|FQTITFN]zRFHhhTBFHhhTBFysdB"[i]
):5;i&&_>1;printf("%s",_-70?_&1?"[]":" ":(_=0,"\n")),_/=2);} /*- Warp -*/

Post a reply to this message

I got it now.  Thanks a lot, everyone!

Post a reply to this message