Hopefully somebody out there can help wit this.

As a part of some of my scenes i'm working on, I want to have a cutaway iew.

the most obvious thing was to just difference a part of the model like so:

  difference
   {
    union
     {
      object { TANK }
      object { TankBuzbee translate <wide*19,0,-wide*4>}
     }
    box { <-1,-1,wide*75> <60,tall*11,-wide*25> rotate <0,45,0>  texture {l3g0_white}
}
    bounded_by { box { <-wall,-wall,-wall> <wide*55,tall*11,wide*55> } }
   }

where the object TANK is a VERY complex model (100,000 + objects)

This works but its inordnately SLOW.

any ideas on how to speedup this  process?

Thanks,
Jon

http://www.apc.net/jon/

Post a reply to this message

jon### [at] apcnet wrote:
: where the object TANK is a VERY complex model (100,000 + objects)

: This works but its inordnately SLOW.

: any ideas on how to speedup this  process?

  If you don't need a surface on the cutted part, you should use a
clipped_by instead of the difference. I think it's faster. (note that
clipped_by works like intersection, not like difference)

-- 
                                                              - Warp. -

Post a reply to this message

Off the top of my head, it seems that you could probably specify a visibility flag,
like
so:

#declare cutaway=x

The x in this case would represent weather or not you were doing a cutaway
perspective.
You can then (for portions of the object that would be entirely obscured), insert a
simple
#if ... #endif structure to eliminate these shapes entirely.  Then, when you insert
the
bounding box, there are less objects accounted for that are not rendered.

I don't know how much faster that will go, but it's something to experiment with, at
any
rate.

jon### [at] apcnet wrote:

> Hopefully somebody out there can help wit this.
>
> As a part of some of my scenes i'm working on, I want to have a cutaway iew.

Post a reply to this message

In article <110### [at] defaultcemediaonenet>,
	jon### [at] apcnet writes:
>Hopefully somebody out there can help wit this.
>any ideas on how to speedup this  process?

Try clipped_by and/or bounded_by instead. Think that is faster.

/Michael

Post a reply to this message

Michael Lundahl <d93### [at] efdlthse> wrote:
: Try clipped_by and/or bounded_by instead. Think that is faster.

  bounded_by will not clip the object if the camera is looking at the
clip surface.

-- 
                                                              - Warp. -

Post a reply to this message

Nieminen Mika <war### [at] assaricctutfi> wrote:

>Michael Lundahl <d93### [at] efdlthse> wrote:
>: Try clipped_by and/or bounded_by instead. Think that is faster.

>  bounded_by will not clip the object if the camera is looking at the
>clip surface.

Thanks everyone for your suggestions!

I forgot about clipped_by.  Turns out its at least 3 times faster than
difference.   I'll post links when the image is done.  Its still
rendering but at least it will be done before the year 2000 :>

Jon.

Post a reply to this message