I was reading up in 3D Graphics and Animatino (@ Barnes and Nobles) and
thumbed through a section the described actually denting the surface of
an object, unlike a normal map which just simulates this effect. Bump
maps are wonderful, but sometimes I need something a little more. For
example, sometimes I need real water. I've been told many ways to get
around bump maps (ie using height fields, etc), but I was wondering if
anything was planned in POV-Ray's future, or if anything did, in fact,
exist, that did physically indent the surface. I realize this would slow
down rendering time (by quite a lot in some cases), but it would be a
nice feature when needed....

Just curious,
Tim Soderstrom
TigerHawk

Post a reply to this message

TigerHawk <Tig### [at] sitcnet> wrote:
: I was reading up in 3D Graphics and Animatino (@ Barnes and Nobles) and
: thumbed through a section the described actually denting the surface of
: an object, unlike a normal map which just simulates this effect. Bump
: maps are wonderful, but sometimes I need something a little more. For
: example, sometimes I need real water. I've been told many ways to get
: around bump maps (ie using height fields, etc), but I was wondering if
: anything was planned in POV-Ray's future, or if anything did, in fact,
: exist, that did physically indent the surface. I realize this would slow
: down rendering time (by quite a lot in some cases), but it would be a
: nice feature when needed....

  I can think only two ways to achieve this:

  1) Making non-linear transformations to the rays. This would be wonderful
but hardly possible.
  2) Creating thousands or millions of triangles around the object. It may
work, but it would require lots of memory. Also placing triangles on the
surface of mathematical objects is a non-trivial task.

  Don't forget that povray models mathematical surfaces. It doesn't model
polygons like scanline renderers do.

-- 
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

Hmm....well that makes sense. I just wasn't sure.  But thinking of that, (when
you mentioned triangles) I've been wondering about the exactness of a smooth
triangle mesh. With primitives, you can get as close as you want and still
retain quality, but what about smoothed meshes? Would the be, for the most
part, true for the mesh also? The reason I ask is I want to make more complex
objects that would be almost impossible to do using CSG and primitives, but
sPatch isn't always what I'm looking for.

Thanks very much for the help,
Tim Soderstrom
TigerHawk

>
>   1) Making non-linear transformations to the rays. This would be wonderful
> but hardly possible.
>   2) Creating thousands or millions of triangles around the object. It may
> work, but it would require lots of memory. Also placing triangles on the
> surface of mathematical objects is a non-trivial task.
>
>   Don't forget that povray models mathematical surfaces. It doesn't model
> polygons like scanline renderers do.
>
> --
> 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 imagine that you could come up with some really cool effects with blobs,
but I wouldn't know exactly how to do that... but I've seen tight blobs and
well controlled blobs posted on this server.

TigerHawk wrote:

> I was reading up in 3D Graphics and Animatino (@ Barnes and Nobles) and
> thumbed through a section the described actually denting the surface of
> an object, unlike a normal map which just simulates this effect. Bump
> maps are wonderful, but sometimes I need something a little more. For
> example, sometimes I need real water. I've been told many ways to get
> around bump maps (ie using height fields, etc), but I was wondering if
> anything was planned in POV-Ray's future, or if anything did, in fact,
> exist, that did physically indent the surface. I realize this would slow
> down rendering time (by quite a lot in some cases), but it would be a
> nice feature when needed....
>
> Just curious,
> Tim Soderstrom
> TigerHawk

--
Joshua English
eng### [at] spiritonecom
IQC: 1946299
"It's a thankless job, but I've got a lot of Karma to burn off."

Post a reply to this message

That's not a bad idea at all....though for huge objects, wow. I think most of
the things I need to do I will try and do with sPatch. Right now I am still
learning how to make it work right (I found the hide function today,
yay!)....I'm having trouble figuring out how to do indentions in an already
created surface...I just haven't used it enough, but it is the only modeller
I have liked thus far (it still gives me the pov edit-by-hand freedom, but
allows me to create complex and curvy shapes....

Thanks for the idea though! For future blob-dudes, I may use that concept!

Tim Soderstrom
TigerHawk


Josh English wrote:

> I imagine that you could come up with some really cool effects with blobs,
> but I wouldn't know exactly how to do that... but I've seen tight blobs and
> well controlled blobs posted on this server.

Post a reply to this message

In article <37B4E33B.5CBBB22F@sitc.net>, TigerHawk <tig### [at] sitcnet> wrote:
>That's not a bad idea at all....though for huge objects, wow. I think most of
>the things I need to do I will try and do with sPatch. Right now I am still
>learning how to make it work right (I found the hide function today,
>yay!)....I'm having trouble figuring out how to do indentions in an already
>created surface...I just haven't used it enough, but it is the only modeller

I think what you're going to need to do is split up the surface and move the 
points on the spline where you moved it, for instance if you have a piece of 
paper:

+--------+
 |         |
 |         |
 |         |
+--------+

You'll need to add some additional sections to it like:

+--+--+--+
 |   |   |   |
+--+--+--+
 |   |   |   |
+--+--+--+
 |   |   |   |
+--+--+--+

and move the points in the middle to bend the surface. If the surface isn't in 
the x, y, or z planes you'll have a real hard time doing this (getting the 
points lines up). sPatch could use a user drawing plane, but then again, 
AutoCAD spoiled me years ago with it.

Hope that is of some help....

PHIL

-----[ to reply, the domain name is "concentric.net" ]-----
Spelling mistakes brought to you courtesy of the
Allentown Public School System.

Post a reply to this message

Have you given any thought to using isosurfaces in the pov super patch?
I have seen planet surfaces, faces, engraved rings, rocks and a
spectacular set of clouds, all done with isosurfaces.
Check the p.b.i ng for examples

TigerHawk wrote:

> I was reading up in 3D Graphics and Animatino (@ Barnes and Nobles) and
> thumbed through a section the described actually denting the surface of
> an object, unlike a normal map which just simulates this effect. Bump
> maps are wonderful, but sometimes I need something a little more. For
> example, sometimes I need real water. I've been told many ways to get
> around bump maps (ie using height fields, etc), but I was wondering if
> anything was planned in POV-Ray's future, or if anything did, in fact,
> exist, that did physically indent the surface. I realize this would slow
> down rendering time (by quite a lot in some cases), but it would be a
> nice feature when needed....
>
> Just curious,
> Tim Soderstrom
> TigerHawk

Post a reply to this message

Yes, it is quite a bit of help. The only thing I must do now is learn to
USE spatch, as it can be time-consuming and very frustrating at times...

Thanks for the help
Tim Soderstrom
Tig### [at] SticNet

Philip Bartol wrote:

> I think what you're going to need to do is split up the surface and move the
> points on the spline where you moved it, for instance if you have a piece of
> paper:
>
> +--------+
>  |         |
>  |         |
>  |         |
> +--------+
>
> You'll need to add some additional sections to it like:
>
> +--+--+--+
>  |   |   |   |
> +--+--+--+
>  |   |   |   |
> +--+--+--+
>  |   |   |   |
> +--+--+--+
>
> and move the points in the middle to bend the surface. If the surface isn't in
> the x, y, or z planes you'll have a real hard time doing this (getting the
> points lines up). sPatch could use a user drawing plane, but then again,
> AutoCAD spoiled me years ago with it.
>
> Hope that is of some help....
>
> PHIL
>
> -----[ to reply, the domain name is "concentric.net" ]-----
> Spelling mistakes brought to you courtesy of the
> Allentown Public School System.

Post a reply to this message

I've given some thought to it, but I have never used iso surfaces before
(though I know what they are). The only thing about iso surfaces is they seem
rather low quality to me. Without a multitude of points, won't you get some
polygonal entities in your Pov-Ray scenes?

Tim Soderstrom
Tig### [at] SticNet

"Mr. Art" wrote:

> Have you given any thought to using isosurfaces in the pov super patch?
> I have seen planet surfaces, faces, engraved rings, rocks and a
> spectacular set of clouds, all done with isosurfaces.
> Check the p.b.i ng for examples
>

Post a reply to this message

In article <37BC7A42.76A41ECC@stic.net>, TigerHawk <tig### [at] sticnet> wrote:
>Yes, it is quite a bit of help. The only thing I must do now is learn to
>USE spatch, as it can be time-consuming and very frustrating at times...
>
>Thanks for the help

Hey, no problem... check out the sPatch tutorials on Dom's site... goto the 
sPatch site and follow the link, it's on the main page (I've got my bookmark 
for it in Netscape, if you need I can E-mail it to you. Once I have some more 
memory I can keep a couple things open at once). They are a big help in 
learning sPatch.

BTW, check out my cup in the binaries.images group, I did that with sPatch in 
the 1st day of using it (but remember that I also spent two years in school 
for CADD <GRIN>) Creating the cup in sPatch was much easier than it would have 
been in AutoCAD years ago.

Any questions you have about sPatch you can E-mail me, I'm not an expert, but 
I should be able to help.

PHIL

---------------------------------------------------

Post a reply to this message