I'm working on a logo for a company. They gave me an EPS file and told me
they wanted part of it to rotate. Fine, I thought. I took the part that was
to be rotated (line art), converted it to a png, and extruded it as a
height_field. I also intersected the height field with a cube to "fill-in"
the back side (now it's not hollow). HOWEVER, when I rotate the object and
view it "on edge" (90 degree rotation), it appears black. Is there anything
I can do about this? I'd post an image of it in p.b.i, but the firewall
here is pretty Nazi, and the web version doesn't allow image posts. Here's
the code snippet, though. It should do the same with most any solid black
and white png. The object should be centered on <0,0,0> for easy viewing.

intersection{
  box { <-.5, -.5, -.5>, <.5, .5, .4>
    texture {pigment {color rgb <0,77/255,0>}}
  }
  height_field {
    png
    "logo.png"
    smooth
    water_level .005
    texture {pigment {color rgb <0,77/255,0>}}
    rotate x*-90
    translate <-.5,-.5,.5>
  }
  scale z*.5
  //rotate y*clock
  rotate y*270
}

Any ideas? I've tried more point lights, area lights, pretty much everything
but radiosity because I'll need this done some time this week.  : )

Thanks All,
Dirk

PS: should you wish to email me, yoink out the caps and the following dot.

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For starters, try applying double_illuminate to the heightfield. If it
doesn't help, then we can think of something else.

-- 
#macro M(A,N,D,L)plane{-z,-9pigment{mandel L*9translate N color_map{[0rgb x]
[1rgb 9]}scale<D,D*3D>*1e3}rotate y*A*8}#end M(-3<1.206434.28623>70,7)M(
-1<.7438.1795>1,20)M(1<.77595.13699>30,20)M(3<.75923.07145>80,99)// - Warp -

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Warp wrote:
>  For starters, try applying double_illuminate to the heightfield. If it
>doesn't help, then we can think of something else.
>
>#macro M(A,N,D,L)plane{-z,-9pigment{mandel L*9translate N color_map{[0rgb x]
>-1<.7438.1795>1,20)M(1<.77595.13699>30,20)M(3<.75923.07145>80,99)// - Warp -
>

Grr...
Tried the double_illuminate; still the same issue. Would an image or two
posted to a web server help describe what I'm seeing?

Dirk

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"D. Stark" <dir### [at] GODHOWIHATESPAMlemongeckoorg> wrote in message
news:web.3d5134ea37bb2ad9746942040@news.povray.org...
>
> intersection{
>   box { <-.5, -.5, -.5>, <.5, .5, .4>
>     texture {pigment {color rgb <0,77/255,0>}}
>   }
>   height_field {
>     png
>     "logo.png"
>     smooth
>     water_level .005
>     texture {pigment {color rgb <0,77/255,0>}}
>     rotate x*-90
>     translate <-.5,-.5,.5>
>   }
>   scale z*.5
>   //rotate y*clock
>   rotate y*270
> }
>

Odd - take out the "smooth" and everything is okay, but double_illuminate has no
effect, wherever you place it.

Hmm, is smooth a "real" effect or just an illusion (like a normal). If it's just
an illusion, maybe the whole concept is a-about-face (like expecting a diff. of
an object with a heavy normal to follow the contour of the normal).

I dunno. Looks like a bug. Anyone got a magnifying glass and some sunshine? Lets
kill it.

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On Wed,  7 Aug 2002 10:55:38 EDT, "D. Stark"
<dir### [at] GODHOWIHATESPAMlemongeckoorg> wrote:

>I also intersected the height field with a cube to "fill-in"
>the back side (now it's not hollow).

I think this shows your problems - height fields don't always work
with CSG because they were never meant to. I had the exact same
problem just a couple of days ago and ended up using an isosurface
instead.


Peter Popov ICQ : 15002700
Personal e-mail : pet### [at] vipbg
TAG      e-mail : pet### [at] tagpovrayorg

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>I think this shows your problems - height fields don't always work
>with CSG because they were never meant to. I had the exact same
>problem just a couple of days ago and ended up using an isosurface
>instead.

Crep. I was hoping I could just extrude the logo into 3D. How's the learning
curve on isosurfaces?  0_o

I just removed the smooth, and now that I've stepped through the animation,
it doesn't look so bad. I also peppered the scene with point lights, and
that helped a few other artifacts. It'll do, especially since the intended
resolution is 100x100, maybe.

Dirk

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On Wed, 07 Aug 2002 20:03:58 +0300, Peter Popov wrote:
> On Wed,  7 Aug 2002 10:55:38 EDT, "D. Stark"
><dir### [at] GODHOWIHATESPAMlemongeckoorg> wrote:
> 
>>I also intersected the height field with a cube to "fill-in"
>>the back side (now it's not hollow).
> 
> I think this shows your problems - height fields don't always work
> with CSG because they were never meant to. I had the exact same

That's not true.  You just have to understand the insideness rules.

-- 
plane{-z,-3normal{crackle scale.2#local a=5;#while(a)warp{repeat x flip x}rotate
z*60#local a=a-1;#end translate-9*x}pigment{rgb 1}}light_source{-9red 1rotate 60
*z}light_source{-9rgb y rotate-z*60}light_source{9-z*18rgb z}text{ttf"arial.ttf"
"RP".01,0translate-<.6,.4,.02>pigment{bozo}}light_source{-z*3rgb-.2}//Ron Parker

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D. Stark <dir### [at] godhowihatespamlemongeckoorg> wrote:
> Would an image or two
> posted to a web server help describe what I'm seeing?

  It's possible.

-- 
#macro N(D)#if(D>99)cylinder{M()#local D=div(D,104);M().5,2pigment{rgb M()}}
N(D)#end#end#macro M()<mod(D,13)-6mod(div(D,13)8)-3,10>#end blob{
N(11117333955)N(4254934330)N(3900569407)N(7382340)N(3358)N(970)}//  - Warp -

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On 7 Aug 2002 13:58:18 -0400, Ron Parker <ron### [at] povrayorg>
wrote:

>> I think this shows your problems - height fields don't always work
>> with CSG because they were never meant to. I had the exact same

>That's not true.  You just have to understand the insideness rules.

I do, unless it has it has changed from "everything below goes in" or
unless I've become really stupid since I taught this very trick in the
groups.


Peter Popov ICQ : 15002700
Personal e-mail : pet### [at] vipbg
TAG      e-mail : pet### [at] tagpovrayorg

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On Wed, 07 Aug 2002 23:07:56 +0300, Peter Popov wrote:
> On 7 Aug 2002 13:58:18 -0400, Ron Parker <ron### [at] povrayorg>
> wrote:
> 
>>> I think this shows your problems - height fields don't always work
>>> with CSG because they were never meant to. I had the exact same
> 
>>That's not true.  You just have to understand the insideness rules.
> 
> I do, unless it has it has changed from "everything below goes in" or
> unless I've become really stupid since I taught this very trick in the
> groups.

I'm afraid we can't rule out the second possibility...

-- 
#local R=rgb 99;#local P=R-R;#local F=pigment{gradient x}box{0,1pigment{gradient
y pigment_map{[.5F pigment_map{[.3R][.3F color_map{[.15red 99][.15P]}rotate z*45
translate x]}]#local H=pigment{gradient y color_map{[.5P][.5R]}scale 1/3}[.5F
pigment_map{[.3R][.3H][.7H][.7R]}]}}}camera{location.5-3*z}//only my opinions

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