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From: Anthony Bennett
Subject: Q: Displacement maps.
Date: 27 Mar 1999 09:07:29
Message: <36FCDA10.B750D742@panama.phoenix.net>
Hi everybody. I was wondering why POV doesn't have a displacement maps
feature like other 3d packages. This would allow cool stuff like
spherical heightfields and what-not. Could such a thing be implemented
in POV? If not, why?

Thanks.


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From: Rick
Subject: Re: Displacement maps.
Date: 27 Mar 1999 10:02:33
Message: <36fcf309.0@news.povray.org>
This would be excellent!!!

Anthony Bennett wrote in message <36FCDA10.B750D742@panama.phoenix.net>...
>Hi everybody. I was wondering why POV doesn't have a displacement maps
>feature like other 3d packages. This would allow cool stuff like
>spherical heightfields and what-not. Could such a thing be implemented
>in POV? If not, why?
>
>Thanks.
>


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From: Anthony Bennett
Subject: Re: Q: Displacement maps.
Date: 27 Mar 1999 11:58:30
Message: <36FD02C0.4F3166E6@panama.phoenix.net>
I'm not a good programmer so this is out of my league, but maybe somebody
would like to have a look as this postscript paper I found on displacement
mapping.

Site         http://graphics.stanford.edu/papers/displace/
Paper      http://graphics.stanford.edu/papers/displace/displace.ps


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From: Margus Ramst
Subject: Re: Displacement maps.
Date: 27 Mar 1999 20:48:25
Message: <36fd8a69.0@news.povray.org>
I think this has been discussed before some time ago, but I dont' remember
the thread. Anyway, the main problem is that displacement mapping would
require the object to be converted into a mesh (like the current height
field). This is by no means easy, and I think it's impossible with objects
like julia fractals.
Object meshing would also allow non-linear transformations like twisting,
bending and other cool things.

Margus

Anthony Bennett wrote in message <36FCDA10.B750D742@panama.phoenix.net>...
>Hi everybody. I was wondering why POV doesn't have a displacement maps
>feature like other 3d packages. This would allow cool stuff like
>spherical heightfields and what-not. Could such a thing be implemented
>in POV? If not, why?
>
>Thanks.
>


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From: Lance Birch
Subject: Re: Displacement maps.
Date: 27 Mar 1999 21:49:43
Message: <36fd98c7.0@news.povray.org>
Well, it could be done... all you have to do is specify the bounds of an
object and an XYZ threshold.  If there is an object intersection routine in
POV-Ray (which there has to be somewhere!) then you could make a patch of
POV-Ray to allow keyword access to such a function.  Then all you have to do
is an ordered test from the top of the bounding box to the bottom calling
the routine.  If it returns 1 then you know that the point lies on the
surface of the object, so you can join the previous row of triangles to the
current and so on...  And there you have it, a MESH!  WOO HOO!!!

There is a plug-in for MAX called MAXMath which does exactly that.  I've
also made a small program that does it.  It's not that hard (well, I've
never done the meshing before, but I'm sure some talented programmer out
there could).

Not sure about fractals though... Hmm........

Anyway, hope this helps!  Oh, and also, you'd have to make some new mapping
modes, like shrink-wrap to make it realy useful for displaycement mapping,
or alternatively, you can have it as part of the texture statement.

--
Lance.


---
For the latest 3D Studio MAX plug-ins, images and much more, go to:
The Zone - http://come.to/the.zone


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From: Bob Hughes
Subject: Re: Displacement maps.
Date: 28 Mar 1999 03:02:34
Message: <36FDE214.8BD4DFF4@aol.com>
Believe you've got the mesh thing right; that is, about it being the
reason the displacement hasn't been used.
Most primitives in POV being non-polygon and that conversion you mention
necessary means extra computing.
Anyone want to bet someone more in the know backs me up? Or maybe I will
lose my shirt in this gamble.
Hey, we'll all have computers beyond these puny 500MHz, 256Meg RAM
machines someday though, right? ha-ha, ah, uh...


Lance Birch wrote:
> 
> Well, it could be done... all you have to do is specify the bounds of an
> object and an XYZ threshold.  If there is an object intersection routine in
> POV-Ray (which there has to be somewhere!) then you could make a patch of
> POV-Ray to allow keyword access to such a function.  Then all you have to do
> is an ordered test from the top of the bounding box to the bottom calling
> the routine.  If it returns 1 then you know that the point lies on the
> surface of the object, so you can join the previous row of triangles to the
> current and so on...  And there you have it, a MESH!  WOO HOO!!!
> 
> There is a plug-in for MAX called MAXMath which does exactly that.  I've
> also made a small program that does it.  It's not that hard (well, I've
> never done the meshing before, but I'm sure some talented programmer out
> there could).
> 
> Not sure about fractals though... Hmm........
> 
> Anyway, hope this helps!  Oh, and also, you'd have to make some new mapping
> modes, like shrink-wrap to make it realy useful for displaycement mapping,
> or alternatively, you can have it as part of the texture statement.
> 
> --
> Lance.
> 
> ---
> For the latest 3D Studio MAX plug-ins, images and much more, go to:
> The Zone - http://come.to/the.zone

-- 
 omniVERSE: beyond the universe
  http://members.aol.com/inversez/homepage.htm
 mailto:inv### [at] aolcom?Subject=PoV-News


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From: Lance Birch
Subject: Re: Displacement maps.
Date: 28 Mar 1999 03:59:06
Message: <36fdef5a.0@news.povray.org>
Well, it shouldn't be TOOOOOO system intensive really...  I mean, that's
what MAX does, it uses all triangles afterall... The displacements are
really quite quick... It's not hard for it to compute it necessarily, but it
will use a fair bit of memory.

--
Lance.


---
For the latest 3D Studio MAX plug-ins, images and much more, go to:
The Zone - http://come.to/the.zone


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From: Ken
Subject: Re: Displacement maps.
Date: 28 Mar 1999 04:50:33
Message: <36FDFA5C.BDC312BD@pacbell.net>
Lance Birch wrote:
> 
> Well, it shouldn't be TOOOOOO system intensive really...  I mean, that's
> what MAX does, it uses all triangles afterall... The displacements are
> really quite quick... It's not hard for it to compute it necessarily, but it
> will use a fair bit of memory.
> 
> --
> Lance.
> 
> ---
> For the latest 3D Studio MAX plug-ins, images and much more, go to:
> The Zone - http://come.to/the.zone

  I can write a pov scene that has a camera, lights and 2,000,000
spheres in a file that takes up less that 200 bytes on my hard drive.
Can you honestly say you can do that with Max ?

-- 
Ken Tyler

mailto://tylereng@pacbell.net


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From: Lance Birch
Subject: Re: Displacement maps.
Date: 28 Mar 1999 05:01:01
Message: <36fdfddd.0@news.povray.org>
Yes, I can.  It's called MAXScript.  Just like a macro in POV-Ray.

--
Lance.


---
For the latest 3D Studio MAX plug-ins, images and much more, go to:
The Zone - http://come.to/the.zone


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From: Gordon
Subject: Re: Displacement maps.
Date: 28 Mar 1999 07:47:39
Message: <36fe24eb.0@news.povray.org>
But the problem would be the fact that they are meshes with the problems
inherent in meshes. Mainly straight segments on the edges of things that are
smooth like spheres. This is one of the beauties of POVRay and similar
programs, when you specify a sphere, you can zoom in as close as you like
and it is still a sphere, no straight edges.

MAX is so much faster than POVRay because it is not a ray-tracer. This has
nothing to do with meshes/primitives. I have nothing against MAX, I just
prefer ray-tracing and real primitives.

I'll re-issue Ken's challenge, but the proviso is that I can zoom to any
position and never see a straight line without having to fiddle the scene!

Regards
Gordon
<gbe### [at] birdcameroncomau>


Lance Birch wrote in message <36fdfddd.0@news.povray.org>...
>Yes, I can.  It's called MAXScript.  Just like a macro in POV-Ray.
>
>--
>Lance.
>
>
>---
>For the latest 3D Studio MAX plug-ins, images and much more, go to:
>The Zone - http://come.to/the.zone
>
>


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